Learner GuideCambridge IGCSE®
Biology
0610
Cambridge Secondary 2
Cambridge International Examinations retains the copyright on all its publications. Registered Centres are permitted to copy material from this booklet for their own internal use. However, we cannot give permission to Centres to photocopy any material that is acknowledged to a third party even for internal use within a Centre.
® IGCSE is the registered trademark of Cambridge International Examinations.
© Cambridge International Examinations 2015
Version 2
Contents
How to use this guide ........................................................................................................ 3Section 1: How will you be tested?Section 2: Examination adviceSection 3: What will be tested?Section 4: What you need to knowSection 5: Useful websitesSection 6: Appendices
Section 1: How will you be tested? ..................................................................................... 5About the theory papersAbout the practical papers
Section 2: Examination advice ............................................................................................. 7General adviceExamination questions and marks Command wordsThe style of questionsPaper 1 and Paper 2 advicePaper 3 advicePaper 4 advicePaper 5 and Paper 6
Section 3: What will be tested? ......................................................................................... 27
Section 4: What you need to know ...................................................................................29How to use the table
Section 5: Useful websites .............................................................................................. 101
Section 6: Appendices .................................................................................................... 103Other important information
2 Cambridge IGCSE Biology 0610
How to use this guide
3 Cambridge IGCSE Biology 0610
How to use this guide
It can be used to help you to plan your revision programme for the theory examinations and will explain what we are looking for in the answers you write. It can also be used to help you revise by using the tick boxes in Section 4, ‘What you need to know’, to check what you know and which topic areas of Cambridge IGCSE® Biology you have covered.
The guide contains the following sections:
S ection 1: How will you be tested?This section will give you information about the different types of theory and practical examination papers that are available.
Section 2: Examination adviceThis section gives you advice to help you do as well as you can. Some of the ideas are general advice and some are based on the common mistakes that candidates make in exams.
Section 3: What will be tested?This section describes the areas of knowledge, understanding and skills that you will be tested on.
Section 4: What you need to knowThis shows the syllabus content in a simple way so that you can check:
• the topics you need to know about
• how the Extended syllabus (Supplement) differs from the Core syllabus
• details about each topic in the syllabus
• how much of the syllabus you have covered
Section 5: Useful websites
Section 6: AppendicesThis section covers the other things you need to know, including:
• information about the mathematical skills you need
• information about terminology, units and symbols, and the presentation of data
• the importance of the command words the examiners use in the examination papers
Not all the information will be relevant to you. For example, you will need to select what you need to know in Sections 1 and 3, by fi nding out from your teacher which examination papers you are taking.
How to use this guide
4 Cambridge IGCSE Biology 0610
Section 1: How will you be tested?
5 Cambridge IGCSE Biology 0610
Se ction 1: How will you be tested?
About the papersYou will be entered for three examination papers, two theory papers and one practical paper.
You will need to ask your teacher which practical paper you are taking. Nearer the time of the examination, you will also need to ask which theory papers you are being entered for:
• If your teacher thinks that you should enter for the examination based on the Core syllabus, you will take Paper 1 (theory), Paper 3 (theory) and one of the practical Papers (5 or 6).
• If your teacher thinks that you should enter for the examination based on the Extended syllabus, you will take Paper 1 (theory), Paper 4 (theory) and one of the practical Papers (5 or 6).
Whether you take the Core or Extended papers will depend on the progress your teacher thinks you have made and which option most suits your particular strengths. You should discuss this with your teacher.
About the theory papersThe table gives you information about the theory papers.
Paper How long and how many marks?
What’s in the paper? What’s the % of the total marks?
Paper 1 45 minutes (40 marks)
40 multiple-choice questions. You choose one answer you consider correct from a choice of four possible answers. The paper tests the Core syllabus.
30% (you do either Paper 1 or Paper 2)
Paper 2 45 minutes (40 marks)
40 multiple-choice questions. You choose one answer you consider correct from a choice of four possible answers. The paper tests the Extended syllabus (Core plus Supplement topics).
30% (you do either Paper 1 or Paper 2)
Paper 3 1 hour 15 minutes(80 marks)
Short-answer questions and structured questions. You should write your answers in the spaces provided. The paper tests the Extended syllabus (Core plus Supplement topics).
50% (you do either Paper 3 or Paper 4)
Paper 41 hour 15 minutes(80 marks)
Short-answer questions and structured questions. Questions will be based on the Extended syllabus content (Core and Supplement).
50%
Section 1: How will you be tested?
6 Cambridge IGCSE Biology 0610
About the practical papersTwenty percent of the marks for Cambridge IGCSE Biology are for practical work. Practical work is not based on specifi c syllabus content. You will need to practise the experimental skills listed in the syllabus, and any other information you need will be given in the questions.
You will do one of the practical papers shown in the table. Your teacher will tell you which practical paper you will do.
Paper How long and what it’s marked out of?
What’s iin the test/paper?
Paper 5 Practical Test
1 hour 15 minutes(40 marks)
You do a practical exam, which is supervised by a teacher. There are usually two questions testing fi ve skill areas.
Paper 6 Alternative to Practical
1 hour (40 marks)
You answer a written paper about practical work. There are usually two or three questions, which test the same skill areas as Paper 5.
Here is some more detail about each of the practical papers. If you are unsure of anything, ask your teacher.
Paper 5 Practical TestYou do a practical exam, which is supervised by a teacher. In the exam you are given an instruction sheet which enables you to carry out the experiments, handle the data and draw appropriate conclusions. You may be asked to:
• carefully follow a set of instructions in a particular order.
• use familiar and unfamiliar methods to record observations and make deductions from them by performing simple tests, for example tests for food substances, using hydrogen carbonate indicator, litmus and Universal Indicator paper.
• use a scalpel or razor blade, forceps, scissors and mounted needles skilfully.
• use a hand lens to observe and record information about biological specimens.
• make clear line drawings of specimens.
• perform simple arithmetical calculations. E.g. the magnifi cation of a drawing.
Paper 6 Alternative to PracticalThis is a written paper. You may be asked to:
• carefully follow a set of instructions in a particular order.
• follow familiar and unfamiliar methods to record observations and make deductions from simple tests, for example tests for food substances, using hydrogen carbonate indicator, litmus and Universal Indicator paper.
• observe and record information about biological specimens from images.
• make clear line drawings of specimens from photographs or micrographs.
• perform simple calculations, including the magnifi cation (enlargement) of a drawing.
Section 2: Examination advice
7 Cambridge IGCSE Biology 0610
Section 2: Examination advice
How to use this advice Much of this advice is given in response to the types of answers that candidates have written in the past. The advice is presented under various subheadings to help you when you prepare for your examinations. Some examples of questions and answers are included to illustrate some of the advice.
• Make sure you read all the general advice. These can be important in any of the papers that you take.
• Have a copy of the syllabus to look at as you read through these tips. Note the different columns – the left hand side has all the Core topics; the right hand side has the Supplement topics.
• Make sure you know which examination papers you are taking before you look at the advice for the different papers.
○ You will take a multiple choice paper, either Paper 1, which is set on the Core syllabus, or Paper 2, which is set on the Core and Supplement.
○ You will take EITHER Paper 3, which is set on the Core syllabus, OR Paper 4 which is set on the Core and the Supplement.
○ You will take EITHER Paper 5, which is the Practical Examination, OR Paper 6, which is the written paper about practical work known as the Alternative to Practical (often called the ATP).
General advice• Use your syllabus all the time while you are revising and preparing for the examination papers.
• You must know which topics you will be tested on.
• Make sure you have all the equipment you will need for the exam in a clear, plastic container. You need two pens, pencils (preferably HB or B), a clean eraser, a ruler (which measures in mm), a pencil sharpener and a calculator.
Answering questions
• The questions are meant to let you show the biology that you have studied. When you are writing your answers remember that another person has to be able to read it.
○ Do not waste time by writing out the question before you start to answer.
○ Keep your handwriting clear and legible.
○ Keep your answers on the lines on the question paper. Do not write in the left hand side of the paper or in the column marked For Examiner’s use. This is because papers are scanned and the examiners mark them online. If you write in the margin your answers may not be visible.
○ If you wish to change an answer, cross out your fi rst answer and rewrite. Do not write over what you have already written.
○ If you have to cross out something, put a line through it, do not scribble over it.
○ If you run out of space, use white space on another part of the exam paper for a continuation answer; do not try to squeeze in your answer by using very small writing.
○ If you have to use a different space for a rewritten another answer or to continue an answer, put a note to tell the examiner where it is, e.g. ‘see page 5’.
Section 2: Examination advice
8 Cambridge IGCSE Biology 0610
○ Always try to write accurately using the correct biological terms. Candidates often lose marks because they do not use the vocabulary of biology correctly.
○ Do not use words like ‘it’, ‘they’, ‘effect’, ‘affect’ without any more explanation. A sentence like ‘It has an effect on the body’ or ‘They affect the process’ does not say anything.
Example 1
QuestionState why magnesium ions are important for healthy plant development. [1]
Answers: – “They are needed by the plant” is true but too vague.
– “They are needed by the leaves” is still too vague.
If these are the fi rst answers that come into your head, ask yourself: What is it or they? What is the “need”? – “Magnesium is needed to make chlorophyll” is a better answer and would gain the mark
– “Magnesium is part of each chlorophyll molecule” Good answer, one mark!
○ If you want to use the word ‘it’ or ‘they’ – think ‘what is it?’ or ‘what are they?’ and then phrase your answer more precisely.
○ If you want to use the word ‘affect’ or ‘effect’ – think ‘how do they affect’ or ‘what is the effect that they have?’
Terms
• These are the names used in biology. Many of them are given in the syllabus. These terms will be used in questions. You should make sure you use them correctly in your examination. Ask your teacher if you are unsure of the meanings of the biological terms used in the syllabus and in any textbook you are using. It is a good idea to write your own biological dictionary using the glossaries at the back of books. You will notice that many terms are defi ned in the syllabus, so that is a good place to start when making your own dictionary.
○ Try to use the correct spelling. The person marking your answer will try to recognise what word you mean, but if the spelling is too far out or ambiguous, then they cannot allow you a mark.
○ Some biological terms have very similar spelling. One example is ‘ureter’, urethra’ and ‘uterus’. If the answer is ureter and your mis-spelling is ‘uretus’, it is not clear enough as you could have thought the answer is ‘uterus’. Other common examples are ovum/ova, ovary and ovule; testes and testa; sucrose and sucrase. Make sure you write clearly and always try to spell as accurately as you can.
○ Do not try to mix the spellings of two words when you are not sure which of them is the correct answer. For example, you might write ‘meitosis’ when you are not sure whether the answer is mitosis or meiosis, or urether, when you are not sure if the answer is ureter or urethra. In both cases you would not get the mark.
○ You need to check carefully that you have used the right word when similar terms are used in the same topic, e.g. urea and urine, ureter and urethra, semen and sperm.
Section 2: Examination advice
9 Cambridge IGCSE Biology 0610
Writing in your own words.
• You sometimes have to write two or more sentences to answer a question.
○ Use short sentences. If you write long sentences you can become confused and your meaning is lost. You might also write something contradictory. It is hard for the examiner to fi nd correct statements in a muddled answer.
○ You are often asked to write down something you have learned. Make sure you have learnt the meanings of the common terms used in biology, e.g. photosynthesis, osmosis and fermentation.
○ In the revision checklist there is a list of the terms which you should be able to defi ne. You also need to be able to write down the meaning of more complicated ideas, e.g. levels of organisation, natural selection, artifi cial selection, global warming and eutrophication.
Examination questions and marks
Example 2
It helps to highlight the main features of a question. You cannot use a highlighter pen, so the best thing to do is to underline or circle key words in the questions.
Question
Name the tissue that transports the sugars made by photosynthesis to other parts of the plant [1]
This tells you that should write a one word answer about plant transport of sugars. Underline the command word (which is not always at the start of the question) and the biological terms as you read the question.
• Make sure you know which part of your biology is being tested.
• Read the whole of a question including all the stimulus material and parts (a), (b), (c) (i) and (c) (ii), etc. carefully before you begin to answer. Some of the parts have similar answers so you need to work out the differences between them. If you write exactly the same thing in different parts of the same question, then only one of them might be a correct answer.
• There is often stimulus material for each question. This might be a photograph, diagram, drawing, fl ow chart, table of data, graph or just some text. Read all of this information carefully and study any pictures, tables or graphs that are included. All of it is relevant to the questions.
• The stimulus material is often about something you have not studied. Do not panic. There will be enough information in the question for you to work out an answer. You are being tested on your ability to apply your knowledge to new information.
• All the different parts of a question may be about the same topic, e.g. digestion or photosynthesis, but you should be prepared for questions that test different topics, e.g. digestion, enzymes and assimilation.
• Look for clues in the words of the question. For example, if you see the word mammal in the question, you know that the animals are warm blooded and have biological systems like ours.
• If you are only given a Latin name or a name you do not recognise, e.g. eland, look to see if you are told anything about it. If you are told that an eland is a herbivore, then you know it eats plants.
• Answer each question as far as you can. Do not spend a long time staring at a question.
• If you do not know the answer or how to work it out, then leave it and come back to it later. It is best to put a mark by the side of the question so you can fi nd it easily. An asterisk (*) is a good idea or a large question mark against the letter of the part question. Not all part questions have answer lines so you
Section 2: Examination advice
10 Cambridge IGCSE Biology 0610
may not see a question that you have left out when you turn through your script towards the end of the examination.
• Try not to leave blanks. Always check through your script towards the end of the examination. When you come back to a question you may remember what to write as an answer to a question that you left out earlier in the exam.
• Do not waste time by writing about things unrelated to the question.
• In Papers 1 and 2 there is one mark for each question.
• The number of marks is printed on the examination papers for Papers 3, 4, 5 and 6. The mark available for each part question is printed in square brackets, e.g. [2]. The number of marks helps you decide how much to write. The total number of marks for each question is printed at the end of the last question, e.g. [Total: 12].
• The number of marks is a guide to how long to spend on each question or parts of a question.
• Do not waste time and write a long answer for a question which has one or two marks. You will not get any extra marks even if your answer is full of many correct and relevant statements.
• If there are two or more marks do not write the same thing in two different ways, e.g. “The leaf is very large. The leaf has a large surface area”. Notice that the second sentence is more accurate and is preferable to the fi rst one.
Command words• These are called command words and tell you what to do.
• You can fi nd all the command words in the Glossary of terms used in science papers which is at the end of your syllabus.
• If a question asks you to ‘Name’ or ‘State’ two things only the fi rst two will be marked. Use the numbered lines for your answers if they are given on the question paper. If you write more than two and the fi rst is correct, the second one is wrong, and the third one correct, you will only get one mark.
• Some questions have two commands in the question, for example ‘Predict and explain’. This means you have to say what you think will happen AND then say why you think it will happen. Usually the word and is printed in bold type to help you. See the section below for advice about answering questions that have two command terms and require an extended answer.
• The table on the following page has a list of terms used in biology papers to tell you what to do in an answer. Make sure you know what you should do in response to each command word.
Example 3
Question 1
Name the process by which green plants make sugars. [1]All you need to write for your answer is ‘photosynthesis’.
Question 2
Defi ne the term photosynthesis. [2]This requires a full sentence:
‘The process by which green plants make carbohydrates from raw materials using energy from light’. This is very similar to the defi nition given in the syllabus so would easily gain both marks.
Section 2: Examination advice
11 Cambridge IGCSE Biology 0610
• You can fi nd out more about command terms in the ‘Glossary of terms used in science papers’ towards the end of the syllabus. These notes should help you know how to respond to each of the command words.
Command words What you should do in response to each command word
Defi ne Give a defi nition – use the defi nitions given in the syllabus
What do you understand by the term .....?
Give a defi nition or a fairly brief explanation of what the term means. You can use an example to illustrate if this seems appropriate
State Brief answer – maybe one word or a phrase
List A number of brief answers should be given; usually you are asked for a specifi c number of points. You do not gain extra marks by writing more than the number stated
Describe You may have to describe the steps in a process or describe the appearance of a biological structure
You may also have to describe some data given in a table or a graph. Make sure you have the correct vocabulary for such a description. Use the words increase, decrease, constant, peak, maximum, minimum, etc.
Explain This is not the same as describe. You should give an answer that has some reasons. You may have to explain why something happens or how it happens
Discuss You may be asked to discuss advantages and disadvantages – so make sure you give some of both. Much depends on the type of question, but ‘discuss’ usually means you should give different sides of a story or an argument
Outline This is not the same as describe. You should give the main important points without any detail
Predict This means you should state what you think will happen. You may be asked to justify your prediction or explain it; explanation is not required if all the question says is “predict....”
Suggest This is often used when there is no single correct answer; you should look through the information you have been given for some clues as to what to ‘suggest’ in response to the question. Many problem-solving questions use this command word
Calculate This is obvious; make sure you know how to calculate percentages, percentage changes, rates and ratios (for genetics). Always give your working even if not asked. Always make sure you use the correct units
Measure You should use a suitable measuring instrument to take a reading. Usually this involves using a ruler to measure to the nearest mm. Make sure you write down the unit after the numerical answer
Section 2: Examination advice
12 Cambridge IGCSE Biology 0610
Command words What you should do in response to each command word
Determine This is not the same as ‘measure’. Either you should explain how an experiment should be set up to take measurements or how you should make a calculation from some results or data given in a table or graph
Estimate You do not have to give an accurate answer – but your answer (which is usually numerical) should only be approximate
Sketch This is usually used about graphs. You should put a line (straight or curved) on a pair of axes. This may be a graph that has a line on it already or it may be pair of axes printed on the exam paper without a line or curve
The style of questionsIdentify features of cells, tissues, organs or other structures• You may be expected to name some structures that are identifi ed by letters on a diagram or drawing.
• You may have to put labels on a diagram using label lines.
Example 4
QuestionUse label lines to identify the following on the drawing of a fl ower: petal, sepal and stamen. [3]To answer this question: • You have to know the structure of a fl ower.
• You also have to be able to fi nd the structures on a diagram of a fl ower that you may never have studied.
• You then have to draw a label line to the structure and write the name next to the labelling line. If you do not draw a label line you may not get any marks even if you have found the correct structure.
Use information given in the question• Questions may ask you to ‘Use examples from...’ or ‘Use only the information in ....’ or ‘With reference
to Fig. 6.2’. If you read instructions like these, fi nd out what you are expected to use as examples or take information from. You will not get any marks if you use examples from somewhere else. The information can be given to you in different ways:
○ a diagram, such as a food web, a set of apparatus or a biological structure;
○ a graph, which could be a line graph, a bar chart or a histogram – always check the headings and units carefully;
○ a table – always read carefully the headings of the columns and/or rows and look for any units.
Section 2: Examination advice
13 Cambridge IGCSE Biology 0610
Example 5
You may have to give examples to show that you understand an idea in biology.
Question that includes a food web as its stimulus material.
Name one example of each of the following from the food web: producer, primary consumer and tertiary consumer.
• To answer this question you have to know defi nitions of producers, primary consumers and tertiary consumers. Then you have to show that you understand how these terms apply to the food web shown in the diagram. If you put examples from other food webs you have learned, you will not get any marks.
Example 6
Question that includes a diagram of a cross section of a leaf.
Describe and explain the advantage of the distribution of chloroplasts in leaves, as shown in the diagram.
• To answer this question you have to observe the diagram and describe which cells have the most chloroplasts. Then you have to work out why this arrangement might help photosynthesis. If you only write about the functions of chloroplasts you will not get any marks.
Interpreting tables and graphs• The stimulus material may be in the form of a table, line graph, bar chart or histogram.
• Always read the introductory text very carefully before you study the table or graph. Underline key points in the information that you are given. In Paper 4, there may be quite a bit of introductory text explaining how the information was collected, e.g. from an investigation.
Tables
• Look at the column and row headings in a table and make sure you understand them. If you have read the introduction carefully, then you will.
• Find the units that have been used. Make sure you use them if you give any fi gures in your answer.
• Use a ruler to help read the table. Start on the left with the fi rst column. This should be the independent variable and should increase in steps. Now put the ruler to the right of the next column and look at the fi gures in this second column. Look for a pattern or trend in the fi gures. Identify the pattern or trend fi rst before thinking of an explanation. Move the ruler across to the right of the third column if there is one and continue in the same way. It may help to sketch a little graph on the exam paper to help you identify any pattern or trend.
Line graphs
• Look carefully at the x-axis which is the independent variable and make sure you understand what has been changed. Look carefully at the y-axis which is the dependent variable. Both variables should be described in the introduction to the question.
• Put your ruler against the y -axis and move it gradually across the graph from left to right. Follow the pattern or trend of the line (or each line if there is more than one). Mark on the graph where something signifi cant happens. For example, the line might show that the dependent variable becomes constant (gives a fl at horizontal line).
Section 2: Examination advice
14 Cambridge IGCSE Biology 0610
Bar charts and histograms
• Look carefully at the x-axis and the y-axis to see what has been plotted. Again, it is a good idea to move a ruler across the bar graph or histogram to help you concentrate on one aspect at a time. You can identify the highest and lowest fi gures and see if there is any pattern.
• You should make yourself some notes about the table, graph or histogram before answering the questions.
• On Papers 3 and 4, you might be asked to complete a graph, bar chart or histogram. If so, you should look carefully at the question to see what you are being asked to do. You may have to add one or more points to a line graph and then add a suitable line. There is advice about how to draw lines on line graphs in the section of general advice for Papers 5 and 6.
Calculations• If you are asked to do a calculation:
○ You may have to fi nd the fi gures from a table or graph.
○ Write out all the working for your calculation. If you make a mistake and give the wrong answer, you may well be given marks for showing how to do the calculation.
○ Make sure that you show the units in the calculation.
○ If the units are not given on the answer line, then make sure you write them after your numerical answer.
○ Often you will be asked to carry out a calculation and add the result to a table. Always express your answer in the same way as the fi gures given in the table. If the other fi gures are 5.6 and 4.6, then your answer should be given to one decimal place, even if the answer is a whole number where you should write 7.0, not 7.
○ If you use a calculator, round up or down the fi gures – do not copy all the fi gures after the decimal point.
Equations ○ If you are taking Paper 3, then you should know word equations for photosynthesis, aerobic and
anaerobic respiration. If you are taking Paper 4, then you should also know the chemical equations and be able to use the chemical symbols correctly. You should know the correct formulae for the compounds involved.
○ If you are asked to give either a word or a symbol equation, do not combine symbols and words in the same answer.
Section 2: Examination advice
15 Cambridge IGCSE Biology 0610
Example 7
Question Write the word equation for anaerobic respiration in yeast [2]
Correct answer:
glucose → carbon dioxide + ethanol + energy
This is an incorrect answer: “glucose → CO2 + ethanol and energy”, as there is a mixture of words and symbols. It would probably get one mark out of two.
Question Write the chemical equation for anaerobic respiration in yeast [2]
Correct answer:
C6H12O6 → 2C2H5OH + 2CO2 + energy
Note that you should use subscripts correctly when writing out the formulae of glucose, alcohol (ethanol), carbon dioxide, lactic acid and water in these equations.
Section 2: Examination advice
16 Cambridge IGCSE Biology 0610
Example 8
Question State two ways in which arteries differ from veins. [2]
Correct answer:1 Arteries have thicker walls than veins.2 Veins have semi-lunar valves, but arteries do not.
Ambiguous answer:1 They have thick walls.2 They don’t have valves.
No marks would be given to the second answer as the comparisons have not been made.
QuestionComplete the table to compare the structure of arteries with the structure of veins [2]Correct answer
Arteries Veins
has thick wall has thin wall
thick muscle layer very thin muscle layer
Incorrect answers as the comparisons are not made between the same features.
Arteries Veins
thick wall thick elastic layer
no valves small amount of muscle
In cases like this, it is much better to have an extra column that gives the features to be compared:
Feature Arteries Veins
thickness of wall thicker thinner
valves absent present
This ensures that you make direct comparisons in each row of the table. You can always add a fi rst column if it is not included in the question.
Section 2: Examination advice
17 Cambridge IGCSE Biology 0610
Making comparisons • If you are asked to compare two things make sure you make it clear which thing you are writing about.
○ The question may ask you to compare two structures or two processes that you have learnt about. Sometimes you may be expected to do this on answer lines in which case you must make clear the items that you are comparing (see Example 8).
○ You may be given a table to complete. This may be blank and you have to fi ll it in, or it may already have some entries and you complete it.
○ If you are given lines to make the comparison, it is perfectly acceptable to draw a table for your answer.
○ A question may give a table of data and then ask you about it. Make sure you only use information from the table; for example, in a table that shows the composition of normal breast milk and colostrum, you can see which milk contains more fat, protein and sugar. Your answers should start with ‘colostrum has more …….. than breast milk’ or ‘breast milk has more …… than colostrum’. Do not put ‘It has more protein’.
• Extended writing. You are required to write longer answers to questions that have four or more marks. There are more of these questions in Paper 4 than in Paper 3.
Example 9
QuestionExplain what happens if excess nitrogen fertiliser is washed into a stream or pond [4]
The mark scheme for a question like this will have a list of points that the examiner will be looking for in your answer. There will be more points than there are marks, so you do not need to put them all in your answer. The points for this question could be:
– Algae and aquatic plants grow faster using the fertiliser.
– Algae cover the water surface.
– Light cannot pass to aquatic plants lower down.
– These plants die.
– Bacteria/decomposers, decay or feed on the dead plants.
– Bacteria/decomposers, increase in numbers.
– Bacteria/decomposers use aerobic respiration.
– They use up oxygen.
– There is not enough oxygen for the respiration of other organisms which live in the water.
– These organisms die.
– The process is called eutrophication.
If your answer is something like ‘The fertiliser causes low oxygen and it affects animals in the water’ you will not get any marks. The answer is much too short and too vague. If your answer is something like ‘The animals do not have enough oxygen for their respiration and they die’ you may get two marks.
Section 2: Examination advice
18 Cambridge IGCSE Biology 0610
○ When you answer these questions always use full sentences if you can. If you fi nd it helps to write bullet points, then make sure each bullet point is a full sentence. If you abbreviate your answer too much by writing notes, then you may not convey enough information to gain the marks.
○ If you are giving a sequence of events (as in Example 9), then you should make sure they are in a logical order. If you are explaining a biological principle or making comparisons, then give the main points fi rst.
○ If you are describing something that moves from one place to another, then make sure you include the direction of movement. For example, ‘water moves by osmosis’ is unlikely to gain a mark unless you include the direction; ‘water enters the cell by osmosis’ is a much better answer.
Paper 1 and Paper 2 advice• You have about one minute to read and answer each question. Each question tests just one topic.
• Some questions test what you know and understand. For example: What tissue in the eye detects light?
• Some questions test if you can apply what you have learned to understand new data. These questions will often have a diagram, graph or table to use.
• Try to decide what the question is testing as you are reading it. The sequence of questions usually follows the sequence of topics in the syllabus.
Example 10
QuestionFour blood vessels are labelled as A, B, C and D on a diagram of the human circulatory system. This is followed by the question:In which vessel will absorbed alcohol fi rst be found?
You need to think about what the question is asking • Is it about digestion?
• Is it about excretion (of alcohol)?
• Is it about the circulation?
The question is asking about something absorbed from the gut to be transported, so it is about circulation. • Which vessel carries substances absorbed by the gut?
• Answer ‘The Hepatic Portal Vein’.
So you have to decide whether the vessel is an artery or a vein, then realise that it is a vein taking blood away from the organ that absorbs alcohol.
Then choose the letter which labels the hepatic portal vein.
Section 2: Examination advice
19 Cambridge IGCSE Biology 0610
• Do not try to fi nd a pattern in the order of your answers (e.g. A, B, C, D, A, B....)
○ The same letter could be the correct answer for several questions in a row.
○ Letter A might be the correct answers for more questions than B, C or D. Or there could be fewer correct answers shown by letter D than any of the others.
○ Do not let what you have chosen for the previous questions infl uence which letter you choose.
Paper 3 advice• Most of the questions require short answers. This means that you write mainly one word or one
sentence answers worth one mark.
• Longer answers will need two or three sentences with two or three different ideas. Always look at the number of marks for each part question to help you decide how much to write.
• Look at the number of command words: ask yourself ‘do you have to do one or two things?’
• Use the lines given. Stick to the point and do not write too much.
• Only give the number of answers that are asked. Use the numbered lines and give one answer per line.
• There will only be a few parts of questions that need extended writing. These will have four [4] or [5] marks. The question will often be related to some information you are given. You will need to write four or fi ve sentences in a sequence that makes sense. You can think of it like ‘telling a story with a beginning, a middle and an end’. Remember to refer to any information you are given.
Paper 4 advice• There is more to read in this paper than in Papers 1, 2 or 3.
• Many questions will be based on one, two or three sentence answers. Always look carefully at the number of marks for each part question.
• Look carefully at the number of command words – do you have to do one or two things, for example describe and explain.
• Look carefully to see if you are asked for an actual number of answers. Only give that number. Use the numbered lines and give one answer per line.
• There are questions that may start in one part of the syllabus and link to another, e.g. the information could be about the animals in a particular habitat and what they eat. The fi rst parts of the question might be about the food chains or food webs which include these animals. A later part of the question could be about teeth or about factors in the environment.
• You are likely to be asked to interpret unfamiliar data, e.g. results from an experiment that you may not have carried out or could not be carried out in a school. Do not be put off. Follow the same advice as before. There will always be enough information in the question for you to answer it.
• You are likely to have questions about events and situations that are new to you. Do not be put off. The question will tell you all you need to know. Read the information carefully and if it is not immediately apparent, look for clues that will tell you which part of the syllabus the question is about.
Section 2: Examination advice
20 Cambridge IGCSE Biology 0610
Paper 5 and Paper 6
General advice
• Read through the questions carefully, looking to see how many marks are given for each question.
• In Paper 5, you have to follow a set of instructions. Read these to the end fi rst, before you start.
• In Paper 6, you will have to read some information about an experiment. Again, read these very carefully.
• Divide the time of your examination in proportion to the marks given.
• If you are taking Paper 6, make sure that you have done plenty of practical work so you can imagine what has happened to obtain the results that you will process, analyse and interpret in the questions.
• Make sure that you have a sharp pencil to use for making drawings and drawing graphs and charts. Do not draw in ink because you cannot make changes as you can when using a pencil.
• Make sure you have a good, clean eraser for rubbing out your pencil lines if necessary. Do not press too hard when using a pencil for making drawings, graphs or charts. Sometimes it is hard for an examiner to tell which is your fi nal line on a scanned script.
Recording your observationsIn both papers you are expected to make observations and record them.
• You can record your observations:
○ as statements in writing
○ in tables
○ by using drawings
○ by constructing tally charts
• You can process your observations by:
○ carrying out calculations, e.g. percentages and percentage changes
○ plotting graphs – line graphs, bar charts and histograms.
• Use all the space available on the paper for your observations.
• Do not write an explanation until the question asks for one.
• Use a sharp HB or B pencil. It can be rubbed out easily if you need to correct a mistake. Use a good eraser as traces of pencil lead are detected when your paper is scanned.
• Do not forget headings for the columns and the rows in tables and in axes on graphs. Do not forget to include the units.
• Make drawings as big as the space allows.
• Use a ruler for labelling lines.
• Label in pencil.
• Use one clear continuous outline not an artistic drawing. Do not shade other than using very light dots.
Section 2: Examination advice
21 Cambridge IGCSE Biology 0610
Drawing tables
• If you are asked to draw a table:
○ Use a ruler and a pencil to draw the table. Make sure you rule lines for the columns and the rows.
○ Write headings for each column and/or row of the table.
○ Write in units if they are needed, e.g. volume of water/cm3, mass of seed/g. The unit should be written after the oblique line (forward slash).
○ Do not put units in the table spaces where you write numbers.
• Make sure you use the same number of decimal places in each column and/or row.
○ If you are asked to draw and/or complete a tally chart for recording data:
○ Make sure that you rule up a table and use clear headings.
○ Record the numbers by using strokes and putting an oblique line to represent 5: /// = 3; //// = 4 and //// = 5
○ Include a column to show the total numbers.
Drawing line graphs
• If you are asked to draw a graph:
○ Choose a scale which uses most of the grid provided on the exam paper.
○ Choose a simple scale, e.g. one large square is equal to 1, 2, 5 or 10 units in the data. Do not make it diffi cult to plot the data by using a scale such as one large square = 3 or 6.
○ Write the name of each axis and the correct unit, e.g. rate of water loss/g per h, temperature/°C, time/s.
○ Plot the points exactly using a sharp pencil. Draw the points lightly so that you can rub them out if you need to. Make them more defi nite when you are sure they are right.
○ Use a cross (x) or a dot in a circle ( ) for your plot points. Do not use a single dot as it may not be seen after you have drawn your line.
○ If you have to plot two lines on a graph, use two different symbols for the plot points. You can use a cross, a dot in a circle or a plus sign (+). Label each line carefully or use a key. Use a pencil for both lines; do not use a blue or black pen or different colours as these do not show up on scanned scripts.
○ Read the question carefully before you put a line in the graph. Look carefully at the points. You have to decide whether to use a straight line of best fi t, a smooth curve of best fi t or join the points by straight lines. Always use a sharp pencil.
○ Remember that lines of best fi t do not have to pass through the point where the two axes meet (the origin). If you are sure that 0, 0 is a point then you can include it. For example, in an investigation of the effect of the concentration of enzyme on enzyme activity 0, 0 means that there is no enzyme present. If there is no enzyme there can be no activity, so 0, 0 could be included.
• Do not extend your line graph beyond the last plotted point.
Bar charts have separate columns that do not touch – there are gaps in between; histograms have columns that do touch each other. Bar charts are used to show data on discontinuous variables, for example blood groups, eye colour, etc.; histograms are used to show data on continuous variables, e.g. length, mass, speed, volume, etc.
Section 2: Examination advice
22 Cambridge IGCSE Biology 0610
Drawing bar charts
• You may have to draw a bar chart (Papers 5 or 6) or add some data to a bar chart (Papers 3 and 4). You draw a bar chart when you have different categories, such as the numbers of six different species in a habitat.
○ Choose a scale which uses most of the grid provided on the exam paper; do not make the chart too small.
○ Draw the chart in pencil.
○ Rule the columns evenly so that they are all the same width.
○ Take care to rule the top of each block in the correct place – double check with the table of data each time.
○ The spaces between the columns on the x-axis should be identical; they should be the same length, e.g. one large square on graph paper.
○ The y-axis should be properly scaled with equal intervals just as in a line graph.
○ The y-axis should be labelled with units.
○ The lines or blocks can be arranged in any order, but to make comparisons it helps if they are arranged in descending or ascending order of size.
○ You should identify each block by putting a label directly underneath each block. Do not shade the blocks or colour code them.
Drawing histograms
• Histograms are ways of displaying the variation in a particular feature, for example the lengths of leaves on a tree. If you measure the lengths of leaves you would have to divide the data into classes, such as 50–54 mm, 55–59 mm, 60–64 mm, etc. The numbers would be recorded in a tally table.
○ Choose a scale which uses most of the grid provided on the exam paper; do not make the histogram too small.
○ Draw the histogram in pencil. The x-axis represents the independent variable and is continuous. It should be properly scaled and labelled with appropriate units.
○ The blocks should be drawn touching.
○ The area of each block is proportional to the size of the class. It is usual to have similar-sized classes (as in the example above) so the widths of the blocks are the same.
○ The blocks should be labelled either by putting the class ranges (e.g. 60–64, 65–69 etc.) underneath each block or by putting the lowest number in each range (e.g. 60, 65, 70, etc.) under the left-hand side of the relevant block.
○ The y-axis represents the number or frequency and should be properly scaled with equal intervals. It should be labelled with appropriate units.
Section 2: Examination advice
23 Cambridge IGCSE Biology 0610
Planning investigations
Sometimes you are asked to suggest a way of carrying out an investigation or to improve the method that is in the question paper.
• When you read through an investigation try to work out three main things:
1. What is being changed – this is called the independent variable.
2. What is being measured – this is called the dependent variable.
3. What is being kept the same – these are the control variables.
Example 11
In a question to investigate the effect of temperature on enzyme activity:
• the independent variable is temperature.
• the dependent variable may be the time taken for a solution of the substrate to change its appearance.
• the key control variables are the concentration of the enzyme solution, the volume of the enzyme solution, the concentration of the substrate solution and the volume of the substrate solution. These are the variables that must be kept constant if you are to fi nd out the effect of changes in temperature.
• Some investigations need to have two parts:
○ The experimental – which measures the process being studied and contains the living organism, part of an organism (e.g. a leaf) or enzyme being tested.
○ The control – which will be exactly the same as the experimental except that the living organism will be missing or replaced by something non-living. The control shows that the results are due to the activity of the living organism and is not due to the apparatus or an environmental factor.
• All investigations should be repeated to increase the reliability of the results. If the same results are achieved (or the results are very similar) then they are reliable.
• The precision of results taking may not be very good. For example, if you are measuring using a syringe or measuring cylinder it may be diffi cult to measure to the nearest cm3. You should think about ways in which the precision can be improved.
• Give quantities in appropriate terms – avoid the use of term ‘amount’ as this does not convey precise meaning to any specifi c quantity. ‘Amount’ could mean volume, mass or concentration. Always be precise and use these words; avoid writing the word ‘amount’. For example, you can give the volume in cm3, mass in grams and concentration in an appropriate unit such as grams per 100 cm3.
Paper 5 adviceIn Paper 5 you are following instructions, using laboratory equipment, making observations, recording results and drawing conclusions.
• Start by reading the entire fi rst question.
• Think about the apparatus that you will use for each step and imagine using it in your mind.
• Check the time to be allowed and imagine following the instructions.
• Do the same when you are ready to begin the next question.
Section 2: Examination advice
24 Cambridge IGCSE Biology 0610
Following the instructions
• Follow the instructions for practical methods exactly. If you make a change in the method you might alter the results.
• Do not take short cuts.
• Always label test tubes and other containers to help you remember which is which.
• If you are told to ‘Wash the apparatus thoroughly after each use’ make sure you do. If there is anything left in the apparatus the next stage may not work.
• If you have to measure a specimen make sure you draw a line on your drawing to show where you made your measurement.
• It is a good idea to put a tick by the side of each instruction when you have completed it. This helps you to fi nd the right place in the instructions, so that you do not leave out a step or repeat a step when it is not required.
• Keep your exam paper on a part of the bench which you can keep dry. Do not pour liquids or use syringes or pipettes over your exam paper. If you keep our exam paper away from the ‘wet’ part of your bench you are unlikely to spill anything on it.
Recording your observations
• Do not forget that observations can be seen, heard, felt and smelled, e.g. colour, fi zzing, warming, smell of a fl ower, texture (feel) of a fruit.
• You can always fi nd something to observe, so make sure you record something for each observation.
• Write down exactly what you observe.
• e.g. if you add a drop of iodine solution to a drop of starch solution on a white tile, the colour changes.
○ You should write ‘the colour changed from yellow to blue-black’.
○ If you write ‘it turned black’ you have not given all the information.
○ If you add iodine solution to a drop of water on a white tile, you should write down ‘the colour stayed yellow’. If you write ‘the colour stayed the same’, or ‘no change’, you have left out important information.
Drawings
These will be from specimens or photographs.
• Read the question carefully, the drawing may have to be an accurate size e.g. twice the original.
• Make each drawing as big as the space allows.
• Use a ruler for labelling lines.
• Label in pencil.
• Use one clear continuous outline not an artistic drawing. Do not shade other than using very light dots.
• Observe details carefully, such as number of seeds in a seed case, thickness of a layer in a shell, etc. Show these accurately on your drawing.
Section 2: Examination advice
25 Cambridge IGCSE Biology 0610
Taking measurements
• Make your measurements as accurate as you can. Measure to the nearest unit, e.g. mm. Do not try and ‘guess’ 0.5 mm.
• Make sure you put units! Use the correct SI units, do not use other units; for example measure in millimetres not inches.
• Always measure in millimetres, not centimetres.
• If you have to make calculations on your measurements, use the blank pages within the paper but indicate if the answer is continued elsewhere on the blank pages. Do not write in the margins.
• Write neatly and show your working. The person marking your paper might be able to give you marks for knowing what to do if you make a mistake or do not fi nish the calculation.
Conclusions
• Use your own results for your conclusions.
• Before planning what to write for a conclusion, turn back to the beginning of the question and read the introduction. You may have forgotten what you were told about the investigation you have just carried out. Think about the theory and apply it to the results you have obtained.
• Sometimes you are expected to make conclusions about some other data, not the data you have collected.
• Do not write the conclusion you have learned from a class experiment or from theory.
Paper 6 adviceThe topics on Paper 6 will be very similar to those on Paper 5, so the advice is very much the same as for that paper. Because you are not doing any practical work, there is usually a third question.
In this paper you are making observations from information given in the paper, recording results and drawing conclusions. Try to imagine doing the practical which has produced the results in the questions and look very carefully at the information you are given as it will almost certainly be unfamiliar to you.
Recording observations
• Some of your observations are based on photographs or diagrams on the paper.
• Write down exactly what you see – as differences or similarities. Measurements may need to be made and magnifi cations calculation.
• Look carefully at photomicrographs as these will be enlarged, e.g. x 100. If you are asked to calculate a magnifi cation follow these steps:
○ measure the structure in the photograph in millimetres (not centimetres).
○ look for the actual size of the object – you will be given this.
○ divide the length of the structure in the photograph (in mm) by the actual size (in mm).
○ the answer is the magnifi cation; round up or down the answer from your calculator.
○ usually magnifi cations are given as whole numbers, so do not give the answer to one or more decimal places.
Section 2: Examination advice
26 Cambridge IGCSE Biology 0610
If you are asked to calculate an actual size follow these steps:
○ measure the structure in the photograph in millimetres (not centimetres).
○ look for the magnifi cation – you will be given this.
○ divide the length of the structure in the photograph (in mm) by the magnifi cation.
○ the answer is the actual size in millimetres; round up or down the answer from your calculator.
○ actual sizes could be given as whole numbers or you could include one or two decimal places, but no more.
Section 3: What will be tested?
27 Cambridge IGCSE Biology 0610
Section 3: What will be tested?
The examiners will take account of the following areas in your examination papers:
• your knowledge (what you remember) and understanding (how you use what you know and apply it to unfamiliar situations).
• how you handle information and solve problems.
• your use of experimental skills.
These areas of knowledge and skills are called assessment objectives. The theory papers (Papers 1 and 3, or Papers 2 and 4) test mainly Assessment Objective 1 (knowledge with understanding) and Assessment Objective 2 (handling information and problem solving). The purpose of the practical paper (Paper 5 or 6) is to test Assessment Objective 3 (experimental skills). Your teacher will be able to give you more information about how each of these is used in the examination papers.
The table shows you the range of skills you should try to develop:
Assessment Objective
What the skill means?
What you need to be able to do?
AO1 Knowledge with understanding
remembering facts and applying these facts to new situations
1. use scientifi c ideas, facts and theories 2. know scientifi c defi nitions e.g. what is excretion? 3. know about biological apparatus and how it works 4. know about S I units, quantities (e.g. mass) and
symbols (e.g. dm3) 5. understand the importance of science in everyday
life
AO2 Handling information and problem solving
how you extract information and rearrange it in a sensible pattern and how you carry out calculations and make predictions
1. select and organise information from graphs, tables and written text
2. change information from one form to another, e.g. draw chart and graphs from data
3. arrange data and carry out calculations 4. identify patterns from information given and draw
conclusions 5. explain scientifi c relationships, e.g. changes in heart
rate in relation to activity 6. make predictions and develop scientifi c ideas 7. solve problems
AO3 Experimental skills
planning and carrying out experiments and recording and analysing information
1. set up and use apparatus safely 2. make observations and measurements and record
them 3. analyse experimental results and suggest how valid
they are 4. plan and carry out your own experiment and
describe to what extent your plan worked and suggest improvements
Section 3: What will be tested?
28 Cambridge IGCSE Biology 0610
Section 4: What you need to know
29 Cambridge IGCSE Biology 0610
Section 4: What you need to know
The table describes the things you may be tested on in the examination. It is arranged in 21 topic areas. If you are studying only the Core material (Papers 1 and 3), you will need to refer only to the column headed Core material. If you are studying the Extended syllabus (Papers 2 and 4), you will need to refer to both the Core and Supplement material columns. Read Section 1 if you are unsure about which material to use.
How to use the table You can use the table throughout your course to check the topic areas you have covered. You can also use it as a revision aid. When you think you have a good knowledge of a topic, you can tick the appropriate box in the checklist column. The main headings in the topic areas are usually followed by the details of what you should know.
Test yourself as follows:
• cover up the details with a piece of paper.
• try to remember the details.
• when you have remembered the details correctly, put a tick in the appropriate box.
If you use a pencil to tick the boxes, you can retest yourself whenever you want by simply rubbing out the ticks. If you are using the table to check the topics you have covered, you can put a tick in the topic column next to the appropriate bullet point.
The column headed ‘Comments’ can be used:
• to add further information about the details for each bullet point.
• to add learning aids.
• to highlight areas of diffi culty/things which you need to ask your teacher about.
Section 4: What you need to know
30 Cambridge IGCSE Biology 0610
Top
icC
ore
mat
eria
l S
up
ple
men
t m
ater
ial
Yo
u s
ho
uld
be
able
to
: C
hec
klis
t C
om
men
ts
Yo
u s
ho
uld
be
able
to
: C
hec
klis
tC
om
men
ts
1.
Ch
arac
teri
stic
s an
d c
lass
ifi c
atio
n o
f liv
ing
org
anis
ms
1.1
Cha
ract
eris
tics
of li
ving
or
gani
sms
• D
escr
ibe
the
char
acte
ristic
s of
liv
ing
orga
nism
s by
defi
nin
g th
e te
rms:
– m
ovem
ent a
s an
act
ion
by a
n or
gani
sm c
ausi
ng a
cha
nge
of
posi
tion
or p
lace
– re
spira
tion
as t
he c
hem
ical
re
actio
ns in
cel
ls t
hat
brea
k do
wn
nutr
ient
mol
ecul
es a
nd
rele
ase
ener
gy
– se
nsiti
vity
as
the
abili
ty
to d
etec
t an
d re
spon
d to
ch
ange
s in
the
env
ironm
ent
– gr
owth
as
a pe
rman
ent
incr
ease
in s
ize
• D
efi n
e th
e te
rms:
– m
ovem
ent a
s an
act
ion
by a
n or
gani
sm o
r pa
rt o
f an
org
anis
m c
ausi
ng
a ch
ange
of
posi
tion
or p
lace
– re
spira
tion
as t
he
chem
ical
reac
tions
in
cel
ls t
hat
brea
k do
wn
nutr
ient
m
olec
ules
and
re
leas
e en
ergy
for
met
abol
ism
– se
nsiti
vity
as
the
abili
ty to
det
ect
or
sens
e st
imul
i in
the
inte
rnal
or
exte
rnal
en
viro
nmen
t an
d to
m
ake
appr
opria
te
resp
onse
s
– gr
owth
as
a pe
rman
ent
incr
ease
in
siz
e an
d dr
y m
ass
by a
n in
crea
se in
cel
l nu
mbe
r or
cel
l siz
e or
bot
h
Section 4: What you need to know
31 Cambridge IGCSE Biology 0610
Top
icC
ore
mat
eria
l S
up
ple
men
t m
ater
ial
Yo
u s
ho
uld
be
able
to
: C
hec
klis
t C
om
men
ts
Yo
u s
ho
uld
be
able
to
: C
hec
klis
tC
om
men
ts
– re
prod
uctio
n as
the
pr
oces
ses
that
mak
e m
ore
of
the
sam
e ki
nd o
f or
gani
sm
– ex
cret
ion
as re
mov
al f
rom
or
gani
sms
of to
xic
mat
eria
ls
and
subs
tanc
es in
exc
ess
of
requ
irem
ents
– nu
triti
on a
s ta
king
in o
f m
ater
ials
for
ener
gy, g
row
th
and
deve
lopm
ent
– ex
cret
ion
as re
mov
al
from
org
anis
ms
of
the
was
te p
rodu
cts
of m
etab
olis
m
(che
mic
al re
actio
ns
in c
ells
incl
udin
g re
spira
tion)
, to
xic
mat
eria
ls,
and
subs
tanc
es
in e
xces
s of
re
quire
men
ts
– nu
triti
on a
s ta
king
in
of
mat
eria
ls fo
r en
ergy
, gro
wth
and
de
velo
pmen
t; p
lant
s re
quire
ligh
t, c
arbo
n di
oxid
e, w
ater
and
io
ns; a
nim
als
need
or
gani
c co
mpo
unds
an
d io
ns a
nd u
sual
ly
need
wat
er
Section 4: What you need to know
32 Cambridge IGCSE Biology 0610
Top
icC
ore
mat
eria
l S
up
ple
men
t m
ater
ial
Yo
u s
ho
uld
be
able
to
: C
hec
klis
t C
om
men
ts
Yo
u s
ho
uld
be
able
to
: C
hec
klis
tC
om
men
ts
1.2
Con
cept
an
d us
e of
a
clas
sifi c
atio
n sy
stem
• S
tate
tha
t or
gani
sms
can
be
clas
sifi e
d in
to g
roup
s by
the
fe
atur
es t
hat
they
sha
re
• D
efi n
e sp
ecie
s as
a g
roup
of
orga
nism
s th
at c
an r
epro
duce
to
prod
uce
fert
ile o
ffsp
ring
• D
efi n
e an
d de
scrib
e th
e bi
nom
ial
syst
em o
f na
min
g sp
ecie
s as
an
inte
rnat
iona
lly a
gree
d sy
stem
in
whi
ch t
he s
cien
tifi c
nam
e of
an
orga
nism
is m
ade
up o
f tw
o pa
rts
show
ing
the
genu
s an
d sp
ecie
s
• E
xpla
in t
hat
clas
sifi c
atio
n sy
stem
s ai
m t
o re
fl ect
ev
olut
iona
ry r
elat
ions
hips
• E
xpla
in t
hat
clas
sifi c
atio
n is
tra
ditio
nally
bas
ed o
n st
udie
s of
mor
phol
ogy
and
anat
omy
• E
xpla
in t
hat
the
sequ
ence
s of
bas
es in
D
NA
and
of
amin
o ac
ids
in p
rote
ins
are
used
as
a m
ore
accu
rate
mea
ns o
f cl
assi
fi cat
ion
• E
xpla
in t
hat
orga
nism
s w
hich
sha
re a
mor
e re
cent
anc
esto
r (a
re
mor
e cl
osel
y re
late
d)
have
bas
e se
quen
ces
in D
NA
tha
t ar
e m
ore
sim
ilar
than
tho
se t
hat
shar
e on
ly a
dis
tant
an
cest
or
Section 4: What you need to know
33 Cambridge IGCSE Biology 0610
Top
icC
ore
mat
eria
l S
up
ple
men
t m
ater
ial
Yo
u s
ho
uld
be
able
to
: C
hec
klis
t C
om
men
ts
Yo
u s
ho
uld
be
able
to
: C
hec
klis
tC
om
men
ts
1.3
Feat
ures
of
orga
nism
s•
List
the
fea
ture
s in
the
cel
ls o
f al
l liv
ing
orga
nism
s, li
mite
d to
cy
topl
asm
, cel
l mem
bran
e an
d D
NA
as
gene
tic m
ater
ial
• Li
st t
he m
ain
feat
ures
use
d to
pl
ace
anim
als
and
plan
ts in
to t
he
appr
opria
te k
ingd
oms
• Li
st t
he m
ain
feat
ures
use
d to
pl
ace
orga
nism
s in
to g
roup
s w
ithin
the
ani
mal
kin
gdom
, lim
ited
to:
– th
e m
ain
grou
ps o
f ve
rteb
rate
s: m
amm
als,
bird
s,
rept
iles,
am
phib
ians
, fi s
h
– th
e m
ain
grou
ps o
f ar
thro
pods
: myr
iapo
ds,
inse
cts,
ara
chni
ds,
crus
tace
ans
• Li
st t
he f
eatu
res
in
the
cells
of
all l
ivin
g or
gani
sms,
lim
ited
to
ribos
omes
for
pro
tein
sy
nthe
sis
and
enzy
mes
in
volv
ed in
res
pira
tion
• Li
st t
he m
ain
feat
ures
us
ed t
o pl
ace
all
orga
nism
s in
to o
ne
of t
he fi
ve k
ingd
oms:
A
nim
al, P
lant
, Fun
gus,
P
roka
ryot
e, P
roto
ctis
t
• Li
st t
he m
ain
feat
ures
us
ed t
o pl
ace
orga
nism
s in
to g
roup
s w
ithin
the
pl
ant
king
dom
, lim
ited
to f
erns
and
fl ow
erin
g pl
ants
(dic
otyl
edon
s an
d m
onoc
otyl
edon
s)
• Li
st t
he f
eatu
res
of
viru
ses,
lim
ited
to p
rote
in
coat
and
gen
etic
mat
eria
l
1.4
Dic
hoto
mou
s ke
ys•
Con
stru
ct a
nd u
se s
impl
e di
chot
omou
s ke
ys b
ased
on
easi
ly id
entifi
abl
e fe
atur
es
Section 4: What you need to know
34 Cambridge IGCSE Biology 0610
Top
icC
ore
mat
eria
l S
up
ple
men
t m
ater
ial
Yo
u s
ho
uld
be
able
to
: C
hec
klis
t C
om
men
ts
Yo
u s
ho
uld
be
able
to
: C
hec
klis
tC
om
men
ts
2.
Org
anis
atio
n o
f th
e o
rgan
ism
2.1
Cel
l st
ruct
ure
and
orga
nisa
tion
• D
escr
ibe
and
com
pare
the
st
ruct
ure
of a
pla
nt c
ell w
ith a
n an
imal
cel
l, as
see
n un
der
a lig
ht
mic
rosc
ope,
lim
ited
to c
ell w
all,
nucl
eus,
cyt
opla
sm, c
hlor
opla
sts,
va
cuol
es a
nd lo
catio
n of
the
cel
l m
embr
ane
• S
tate
the
fun
ctio
ns o
f th
e st
ruct
ures
see
n un
der
the
light
m
icro
scop
e in
the
pla
nt c
ell a
nd in
th
e an
imal
cel
l
• S
tate
tha
t th
e cy
topl
asm
of
all
cells
con
tain
s st
ruct
ures
, lim
ited
to
ribos
omes
on
roug
h en
dopl
asm
ic r
etic
ulum
an
d ve
sicl
es
• S
tate
tha
t al
mos
t al
l cel
ls,
exce
pt p
roka
ryot
es, h
ave
mito
chon
dria
and
rou
gh
endo
plas
mic
ret
icul
um
• Id
entif
y m
itoch
ondr
ia
and
roug
h en
dopl
asm
ic
retic
ulum
in d
iagr
ams
and
imag
es o
f ce
lls
• S
tate
tha
t ae
robi
c re
spira
tion
occu
rs in
m
itoch
ondr
ia
• S
tate
tha
t ce
lls w
ith h
igh
rate
s of
met
abol
ism
re
quire
larg
e nu
mbe
rs o
f m
itoch
ondr
ia t
o pr
ovid
e su
ffi c
ient
ene
rgy
Section 4: What you need to know
35 Cambridge IGCSE Biology 0610
Top
icC
ore
mat
eria
l S
up
ple
men
t m
ater
ial
Yo
u s
ho
uld
be
able
to
: C
hec
klis
t C
om
men
ts
Yo
u s
ho
uld
be
able
to
: C
hec
klis
tC
om
men
ts
2.2
Leve
ls o
f or
gani
satio
n•
Rel
ate
the
stru
ctur
e of
the
fo
llow
ing
to t
heir
func
tions
:
– ci
liate
d ce
lls –
mov
emen
t of
muc
us in
the
tra
chea
and
br
onch
i
– ro
ot h
air
cells
– a
bsor
ptio
n
– xy
lem
ves
sels
– c
ondu
ctio
n an
d su
ppor
t
– pa
lisad
e m
esop
hyll
cells
–
phot
osyn
thes
is
– ne
rve
cells
– c
ondu
ctio
n of
im
puls
es
– re
d bl
ood
cells
– t
rans
port
of
oxyg
en
– sp
erm
and
egg
cel
ls –
re
prod
uctio
n
• D
efi n
e tis
sue
as a
gro
up o
f ce
lls
with
sim
ilar
stru
ctur
es, w
orki
ng
toge
ther
to
perf
orm
a s
hare
d fu
nctio
n
• D
efi n
e or
gan
as a
str
uctu
re m
ade
up o
f a
grou
p of
tis
sues
, wor
king
to
geth
er t
o pe
rfor
m s
peci
fi c
func
tions
• D
efi n
e or
gan
syst
em a
s a
grou
p of
org
ans
with
rel
ated
fun
ctio
ns,
wor
king
tog
ethe
r to
per
form
bod
y fu
nctio
ns
• S
tate
exa
mpl
es o
f tis
sues
, org
ans
and
orga
n sy
stem
s fr
om s
ectio
ns
6 to
16
Section 4: What you need to know
36 Cambridge IGCSE Biology 0610
Top
icC
ore
mat
eria
l S
up
ple
men
t m
ater
ial
Yo
u s
ho
uld
be
able
to
: C
hec
klis
t C
om
men
ts
Yo
u s
ho
uld
be
able
to
: C
hec
klis
tC
om
men
ts
• Id
entif
y th
e di
ffer
ent
leve
ls
of o
rgan
isat
ion
in d
raw
ings
, di
agra
ms
and
imag
es o
f fa
mili
ar
mat
eria
l
• Id
entif
y th
e di
ffer
ent
leve
ls o
f or
gani
satio
n in
dra
win
gs, d
iagr
ams
and
imag
es o
f un
fam
iliar
m
ater
ial
2.3
Siz
e of
sp
ecim
ens
• C
alcu
late
mag
nifi c
atio
n an
d si
ze
of b
iolo
gica
l spe
cim
ens
usin
g m
illim
etre
s as
uni
ts
• C
alcu
late
mag
nifi c
atio
n an
d si
ze o
f bi
olog
ical
sp
ecim
ens
usin
g m
illim
etre
s an
d m
icro
met
res
as u
nits
3.
Mo
vem
ent
in a
nd
ou
t o
f ce
lls
3.1
Diff
usio
n•
Defi
ne
diff
usio
n as
the
net
m
ovem
ent
of p
artic
les
from
a
regi
on o
f th
eir
high
er
conc
entr
atio
n to
a r
egio
n of
the
ir lo
wer
con
cent
ratio
n do
wn
a co
ncen
trat
ion
grad
ient
, as
a re
sult
of t
heir
rand
om m
ovem
ent
• D
escr
ibe
the
impo
rtan
ce o
f di
ffus
ion
of g
ases
and
sol
utes
• S
tate
tha
t su
bsta
nces
mov
e in
to a
nd o
ut o
f ce
lls b
y di
ffus
ion
thro
ugh
the
cell
mem
bran
e
• S
tate
tha
t th
e en
ergy
for
di
ffus
ion
com
es f
rom
the
ki
netic
ene
rgy
of r
ando
m
mov
emen
t of
mol
ecul
es
and
ions
• In
vest
igat
e th
e fa
ctor
s th
at in
fl uen
ce d
iffus
ion,
lim
ited
to s
urfa
ce
area
, tem
pera
ture
, co
ncen
trat
ion
grad
ient
s an
d di
stan
ce
Section 4: What you need to know
37 Cambridge IGCSE Biology 0610
Top
icC
ore
mat
eria
l S
up
ple
men
t m
ater
ial
Yo
u s
ho
uld
be
able
to
: C
hec
klis
t C
om
men
ts
Yo
u s
ho
uld
be
able
to
: C
hec
klis
tC
om
men
ts
3.2
Osm
osis
• S
tate
that
wat
er d
iffus
es t
hrou
gh
part
ially
per
mea
ble
mem
bran
es
by o
smos
is
• S
tate
tha
t w
ater
mov
es in
and
out
of
cel
ls b
y os
mos
is t
hrou
gh t
he
cell
mem
bran
e
• In
vest
igat
e an
d de
scrib
e th
e ef
fect
s on
pla
nt t
issu
es o
f im
mer
sing
the
m in
sol
utio
ns o
f di
ffer
ent
conc
entr
atio
ns
• S
tate
tha
t pl
ants
are
sup
port
ed b
y th
e pr
essu
re o
f w
ater
insi
de t
he
cells
pre
ssin
g ou
twar
ds o
n th
e ce
ll w
all
• D
efi n
e os
mos
is a
s th
e ne
t m
ovem
ent
of w
ater
m
olec
ules
fro
m a
reg
ion
of h
ighe
r w
ater
pot
entia
l (d
ilute
sol
utio
n) t
o a
regi
on o
f lo
wer
wat
er
pote
ntia
l (co
ncen
trat
ed
solu
tion)
, thr
ough
a
part
ially
per
mea
ble
mem
bran
e
• E
xpla
in t
he e
ffec
ts
on p
lant
tis
sues
of
imm
ersi
ng t
hem
in
solu
tions
of
diff
eren
t co
ncen
trat
ions
by
usin
g th
e te
rms
turg
id, t
urgo
r pr
essu
re, p
lasm
olys
is
and
fl acc
id
• E
xpla
in t
he im
port
ance
of
wat
er p
oten
tial a
nd
osm
osis
in t
he u
ptak
e of
w
ater
by
plan
ts
• E
xpla
in t
he im
port
ance
of
wat
er p
oten
tial a
nd
osm
osis
on
anim
al c
ells
an
d tis
sues
• E
xpla
in h
ow p
lant
s ar
e su
ppor
ted
by t
he t
urgo
r pr
essu
re w
ithin
cel
ls, i
n te
rms
of w
ater
pre
ssur
e ac
ting
agai
nst
an in
elas
tic
cell
wal
l
Section 4: What you need to know
38 Cambridge IGCSE Biology 0610
Top
icC
ore
mat
eria
l S
up
ple
men
t m
ater
ial
Yo
u s
ho
uld
be
able
to
: C
hec
klis
t C
om
men
ts
Yo
u s
ho
uld
be
able
to
: C
hec
klis
tC
om
men
ts
3.3
Act
ive
tran
spor
t•
Defi
ne
activ
e tr
ansp
ort a
s th
e m
ovem
ent
of p
artic
les
thro
ugh
a ce
ll m
embr
ane
from
a r
egio
n of
lo
wer
con
cent
ratio
n to
a r
egio
n of
hi
gher
con
cent
ratio
n us
ing
ener
gy
from
res
pira
tion
• D
iscu
ss t
he im
port
ance
of
act
ive
tran
spor
t as
a
proc
ess
for
mov
emen
t ac
ross
mem
bran
es:
– e.
g. io
n up
take
by
roo
t ha
irs a
nd
upta
ke o
f gl
ucos
e by
ep
ithel
ial c
ells
of
villi
an
d ki
dney
tub
ules
• E
xpla
in h
ow p
rote
in
mol
ecul
es m
ove
part
icle
s ac
ross
a m
embr
ane
durin
g ac
tive
tran
spor
t
4.
Bio
log
ical
mo
lecu
les
• Li
st t
he c
hem
ical
ele
men
ts t
hat
mak
e up
:
– ca
rboh
ydra
tes
– fa
ts
– pr
otei
ns
• S
tate
tha
t la
rge
mol
ecul
es a
re
mad
e fr
om s
mal
ler
mol
ecul
es,
limite
d to
:
– st
arch
and
gly
coge
n fr
om
gluc
ose
– ce
llulo
se f
rom
glu
cose
– pr
otei
ns f
rom
am
ino
acid
s
– fa
ts a
nd o
ils f
rom
fat
ty a
cids
an
d gl
ycer
ol
Section 4: What you need to know
39 Cambridge IGCSE Biology 0610
Top
icC
ore
mat
eria
l S
up
ple
men
t m
ater
ial
Yo
u s
ho
uld
be
able
to
: C
hec
klis
t C
om
men
ts
Yo
u s
ho
uld
be
able
to
: C
hec
klis
tC
om
men
ts
• D
escr
ibe
the
use
of:
– io
dine
sol
utio
n to
test
for
star
ch
– B
ened
ict’s
sol
utio
n to
test
for
redu
cing
sug
ars
– bi
uret
test
for
prot
eins
– et
hano
l em
ulsi
on te
st fo
r fa
ts
and
oils
– D
CP
IP te
st fo
r vi
tam
in C
• E
xpla
in t
hat
diff
eren
t se
quen
ces
of a
min
o ac
ids
give
diff
eren
t sh
apes
to
prot
ein
mol
ecul
es
• R
elat
e th
e sh
ape
and
stru
ctur
e of
pro
tein
m
olec
ules
to
thei
r fu
nctio
n, li
mite
d to
the
ac
tive
site
of
enzy
mes
an
d th
e bi
ndin
g si
te o
f an
tibod
ies
Des
crib
e th
e st
ruct
ure
of
DN
A a
s:
– tw
o st
rand
s co
iled
toge
ther
to fo
rm a
do
uble
hel
ix
– ea
ch s
tran
d co
ntai
ns
chem
ical
s ca
lled
base
s
– cr
oss-
links
bet
wee
n th
e st
rand
s ar
e fo
rmed
by
pairs
of
base
s
Section 4: What you need to know
40 Cambridge IGCSE Biology 0610
Top
icC
ore
mat
eria
l S
up
ple
men
t m
ater
ial
Yo
u s
ho
uld
be
able
to
: C
hec
klis
t C
om
men
ts
Yo
u s
ho
uld
be
able
to
: C
hec
klis
tC
om
men
ts
• S
tate
tha
t w
ater
is im
port
ant
as a
so
lven
t
– th
e ba
ses
alw
ays
pair
up in
the
sam
e w
ay: A
with
T, a
nd
C w
ith G
(ful
l nam
es
are
no
t re
quire
d)
• D
escr
ibe
the
role
s of
w
ater
as
a so
lven
t in
or
gani
sms
with
res
pect
to
dig
estio
n, e
xcre
tion
and
tran
spor
t
5.
En
zym
es
• D
efi n
e th
e te
rm c
atal
yst a
s a
subs
tanc
e th
at in
crea
ses
the
rate
of
a c
hem
ical
rea
ctio
n an
d is
not
ch
ange
d by
the
rea
ctio
n
• D
efi n
e en
zym
es a
s pr
otei
ns t
hat
func
tion
as b
iolo
gica
l cat
alys
ts
• D
escr
ibe
why
enz
ymes
are
im
port
ant
in a
ll liv
ing
orga
nism
s in
ter
ms
of r
eact
ion
spee
d ne
cess
ary
to s
usta
in li
fe
• D
escr
ibe
enzy
me
actio
n w
ith
refe
renc
e to
the
com
plem
enta
ry
shap
e of
an
enzy
me
and
its
subs
trat
e an
d th
e fo
rmat
ion
of a
pr
oduc
t (k
now
ledg
e of
the
ter
m
activ
e si
te is
no
t re
quire
d)
• E
xpla
in e
nzym
e ac
tion
with
ref
eren
ce t
o th
e ac
tive
site
, enz
yme-
subs
trat
e co
mpl
ex,
subs
trat
e an
d pr
oduc
t
• E
xpla
in t
he s
peci
fi city
of
enzy
mes
in t
erm
s of
the
co
mpl
emen
tary
sha
pe
and
fi t o
f th
e ac
tive
site
w
ith t
he s
ubst
rate
Section 4: What you need to know
41 Cambridge IGCSE Biology 0610
Top
icC
ore
mat
eria
l S
up
ple
men
t m
ater
ial
Yo
u s
ho
uld
be
able
to
: C
hec
klis
t C
om
men
ts
Yo
u s
ho
uld
be
able
to
: C
hec
klis
tC
om
men
ts
• In
vest
igat
e an
d de
scrib
e th
e ef
fect
of
chan
ges
in
tem
pera
ture
and
pH
on
enzy
me
activ
ity
• E
xpla
in t
he e
ffec
t of
ch
ange
s in
tem
pera
ture
on
enz
yme
activ
ity in
te
rms
of k
inet
ic e
nerg
y,
shap
e an
d fi t
, fre
quen
cy
of e
ffec
tive
colli
sion
s an
d de
natu
ratio
n
• E
xpla
in t
he e
ffec
t of
cha
nges
in p
H o
n en
zym
e ac
tivity
in t
erm
s of
sha
pe a
nd fi
t an
d de
natu
ratio
n
6.
Pla
nt
Nu
trit
ion
6.1
Pho
tosy
nthe
sis
• D
efi n
e ph
otos
ynth
esis
as
the
proc
ess
by w
hich
pla
nts
man
ufac
ture
car
bohy
drat
es f
rom
ra
w m
ater
ials
usi
ng e
nerg
y fr
om
light
• S
tate
the
wor
d eq
uatio
n fo
r ph
otos
ynth
esis
: car
bon
diox
ide
+
wat
er →
glu
cose
+ o
xyge
n, in
the
pr
esen
ce o
f lig
ht a
nd c
hlor
ophy
ll
• S
tate
the
bal
ance
d ch
emic
al e
quat
ion
for
phot
osyn
thes
is
+
→
+lig
ht2
26
126
2ch
loro
phyl
l6C
O6H
OC
HO
6O
• E
xpla
in t
hat
chlo
roph
yll
tran
sfer
s lig
ht e
nerg
y in
to c
hem
ical
ene
rgy
in m
olec
ules
, for
th
e sy
nthe
sis
of
carb
ohyd
rate
s
• O
utlin
e th
e su
bseq
uent
us
e an
d st
orag
e of
the
ca
rboh
ydra
tes
mad
e in
ph
otos
ynth
esis
Section 4: What you need to know
42 Cambridge IGCSE Biology 0610
Top
icC
ore
mat
eria
l S
up
ple
men
t m
ater
ial
Yo
u s
ho
uld
be
able
to
: C
hec
klis
t C
om
men
ts
Yo
u s
ho
uld
be
able
to
: C
hec
klis
tC
om
men
ts
• In
vest
igat
e th
e ne
cess
ity f
or
chlo
roph
yll,
light
and
car
bon
diox
ide
for
phot
osyn
thes
is, u
sing
ap
prop
riate
con
trol
s
• In
vest
igat
e an
d de
scrib
e th
e ef
fect
s of
var
ying
ligh
t in
tens
ity,
carb
on d
ioxi
de c
once
ntra
tion
and
tem
pera
ture
on
the
rate
of
pho
tosy
nthe
sis,
e.g
. in
subm
erge
d aq
uatic
pla
nts
• D
efi n
e th
e te
rm
limiti
ng fa
ctor
as
som
ethi
ng p
rese
nt
in t
he e
nviro
nmen
t in
su
ch s
hort
sup
ply
that
it
rest
ricts
life
pro
cess
es
• Id
entif
y an
d ex
plai
n th
e lim
iting
fac
tors
of
pho
tosy
nthe
sis
in
diff
eren
t en
viro
nmen
tal
cond
ition
s
• D
escr
ibe
the
use
of c
arbo
n di
oxid
e en
richm
ent,
opt
imum
lig
ht a
nd o
ptim
um
tem
pera
ture
s in
gl
assh
ouse
s in
te
mpe
rate
and
tro
pica
l co
untr
ies
• U
se h
ydro
genc
arbo
nate
in
dica
tor
solu
tion
to
inve
stig
ate
the
effe
ct
of g
as e
xcha
nge
of a
n aq
uatic
pla
nt k
ept
in t
he
light
and
in t
he d
ark
Section 4: What you need to know
43 Cambridge IGCSE Biology 0610
Top
icC
ore
mat
eria
l S
up
ple
men
t m
ater
ial
Yo
u s
ho
uld
be
able
to
: C
hec
klis
t C
om
men
ts
Yo
u s
ho
uld
be
able
to
: C
hec
klis
tC
om
men
ts
6.2
Leaf
str
uctu
re•
Iden
tify
chlo
ropl
asts
, cut
icle
, gu
ard
cells
and
sto
mat
a,
uppe
r an
d lo
wer
epi
derm
is,
palis
ade
mes
ophy
ll, s
pong
y m
esop
hyll,
vas
cula
r bu
ndle
s,
xyle
m a
nd p
hloe
m in
leav
es o
f a
dico
tyle
dono
us p
lant
• E
xpla
in h
ow t
he
inte
rnal
str
uctu
re o
f a
leaf
is a
dapt
ed f
or
phot
osyn
thes
is
6.3
Min
eral
re
quire
men
ts•
Des
crib
e th
e im
port
ance
of:
– ni
trat
e io
ns fo
r m
akin
g am
ino
acid
s
– m
agne
sium
ions
for
mak
ing
chlo
roph
yll
• E
xpla
in t
he e
ffec
ts
of n
itrat
e io
n an
d m
agne
sium
ion
defi c
ienc
y on
pla
nt
grow
th
7.
Hu
man
Nu
trit
ion
7.1
Die
t•
Sta
te w
hat
is m
eant
by
the
term
ba
lanc
ed d
iet f
or h
uman
s
• E
xpla
in h
ow a
ge, g
ende
r an
d ac
tivity
aff
ect
the
diet
ary
need
s of
hum
ans
incl
udin
g du
ring
preg
nanc
y an
d w
hils
t br
east
-fe
edin
g
• D
escr
ibe
the
effe
cts
of
mal
nutr
ition
in r
elat
ion
to
star
vatio
n, c
onst
ipat
ion,
cor
onar
y he
art
dise
ase,
obe
sity
and
scu
rvy
Section 4: What you need to know
44 Cambridge IGCSE Biology 0610
Top
icC
ore
mat
eria
l S
up
ple
men
t m
ater
ial
Yo
u s
ho
uld
be
able
to
: C
hec
klis
t C
om
men
ts
Yo
u s
ho
uld
be
able
to
: C
hec
klis
tC
om
men
ts
• Li
st t
he p
rinci
pal s
ourc
es o
f, a
nd
desc
ribe
the
diet
ary
impo
rtan
ce
of:
– ca
rboh
ydra
tes
– fa
ts
– pr
otei
ns
– vi
tam
ins,
lim
ited
to C
and
D
– m
iner
al s
alts
, lim
ited
to
calc
ium
and
iron
– fi b
re (r
ough
age)
– w
ater
• E
xpla
in t
he c
ause
s an
d ef
fect
s of
vita
min
D a
nd
iron
defi c
ienc
ies
• E
xpla
in t
he c
ause
s an
d ef
fect
s of
pr
otei
n-en
ergy
m
alnu
triti
on, e
.g.
kwas
hior
kor
and
mar
asm
us
Section 4: What you need to know
45 Cambridge IGCSE Biology 0610
Top
icC
ore
mat
eria
l S
up
ple
men
t m
ater
ial
Yo
u s
ho
uld
be
able
to
: C
hec
klis
t C
om
men
ts
Yo
u s
ho
uld
be
able
to
: C
hec
klis
tC
om
men
ts
7.2
Alim
enta
ry
cana
l•
Defi
ne
inge
stio
n as
the
tak
ing
of
subs
tanc
es, e
.g. f
ood
and
drin
k,
into
the
bod
y th
roug
h th
e m
outh
• D
efi n
e m
echa
nica
l dig
estio
n as
the
bre
akdo
wn
of f
ood
into
sm
alle
r pi
eces
with
out
chem
ical
ch
ange
to
the
food
mol
ecul
es
• D
efi n
e ch
emic
al d
iges
tion
as t
he
brea
kdow
n of
larg
e, in
solu
ble
mol
ecul
es in
to s
mal
l, so
lubl
e m
olec
ules
• D
efi n
e ab
sorp
tion
as t
he
mov
emen
t of
sm
all f
ood
mol
ecul
es a
nd io
ns t
hrou
gh t
he
wal
l of
the
inte
stin
e in
to t
he b
lood
• D
efi n
e as
sim
ilatio
n as
the
m
ovem
ent
of d
iges
ted
food
m
olec
ules
into
the
cel
ls o
f th
e bo
dy w
here
the
y ar
e us
ed,
beco
min
g pa
rt o
f th
e ce
lls
• D
efi n
e eg
estio
n as
the
pas
sing
ou
t of
foo
d th
at h
as n
ot b
een
dige
sted
or
abso
rbed
, as
faec
es,
thro
ugh
the
anus
• D
escr
ibe
diar
rhoe
a as
the
loss
of
wat
ery
faec
es
• O
utlin
e th
e tr
eatm
ent
of d
iarr
hoea
us
ing
oral
reh
ydra
tion
ther
apy
Section 4: What you need to know
46 Cambridge IGCSE Biology 0610
Top
icC
ore
mat
eria
l S
up
ple
men
t m
ater
ial
Yo
u s
ho
uld
be
able
to
: C
hec
klis
t C
om
men
ts
Yo
u s
ho
uld
be
able
to
: C
hec
klis
tC
om
men
ts
• D
escr
ibe
chol
era
as a
dis
ease
ca
used
by
a ba
cter
ium
• Id
entif
y th
e m
ain
regi
ons
of t
he
alim
enta
ry c
anal
and
ass
ocia
ted
orga
ns, l
imite
d to
mou
th, s
aliv
ary
glan
ds, o
esop
hagu
s, s
tom
ach,
sm
all i
ntes
tine
(duo
denu
m
and
ileum
), pa
ncre
as, l
iver
, gal
l bl
adde
r an
d la
rge
inte
stin
e (c
olon
, re
ctum
, anu
s)
• D
escr
ibe
the
func
tions
of
the
regi
ons
of t
he a
limen
tary
can
al
liste
d ab
ove,
in r
elat
ion
to
inge
stio
n, d
iges
tion,
abs
orpt
ion,
as
sim
ilatio
n an
d eg
estio
n of
foo
d
• E
xpla
in t
hat
the
chol
era
bact
eriu
m p
rodu
ces
a to
xin
that
cau
ses
secr
etio
n of
chl
orid
e io
ns
into
the
sm
all i
ntes
tine,
ca
usin
g os
mot
ic
mov
emen
t of
wat
er
into
the
gut
, cau
sing
di
arrh
oea,
deh
ydra
tion
and
loss
of
salts
fro
m
bloo
d
Section 4: What you need to know
47 Cambridge IGCSE Biology 0610
Top
icC
ore
mat
eria
l S
up
ple
men
t m
ater
ial
Yo
u s
ho
uld
be
able
to
: C
hec
klis
t C
om
men
ts
Yo
u s
ho
uld
be
able
to
: C
hec
klis
tC
om
men
ts
7.3
Mec
hani
cal
dige
stio
n•
Iden
tify
the
type
s of
hum
an t
eeth
(in
ciso
rs, c
anin
es, p
rem
olar
s an
d m
olar
s)
• D
escr
ibe
the
stru
ctur
e of
hum
an
teet
h, li
mite
d to
ena
mel
, den
tine,
pu
lp, n
erve
s an
d ce
men
t, a
s w
ell
as t
he g
ums
• D
escr
ibe
the
func
tions
of
the
type
s of
hum
an t
eeth
in
mec
hani
cal d
iges
tion
of f
ood
• S
tate
the
cau
ses
of d
enta
l dec
ay
in t
erm
s of
a c
oatin
g of
bac
teria
an
d fo
od o
n te
eth,
the
bac
teria
re
spiri
ng s
ugar
s in
the
foo
d,
prod
ucin
g ac
id w
hich
dis
solv
es
the
enam
el a
nd d
entin
e
• D
escr
ibe
the
prop
er c
are
of
teet
h in
ter
ms
of d
iet
and
regu
lar
brus
hing
Section 4: What you need to know
48 Cambridge IGCSE Biology 0610
Top
icC
ore
mat
eria
l S
up
ple
men
t m
ater
ial
Yo
u s
ho
uld
be
able
to
: C
hec
klis
t C
om
men
ts
Yo
u s
ho
uld
be
able
to
: C
hec
klis
tC
om
men
ts
7.4
Che
mic
al
dige
stio
n•
Sta
te t
he s
igni
fi can
ce o
f ch
emic
al
dige
stio
n in
the
alim
enta
ry c
anal
in
pro
duci
ng s
mal
l, so
lubl
e m
olec
ules
tha
t ca
n be
abs
orbe
d
• S
tate
the
fun
ctio
ns o
f en
zym
es a
s fo
llow
s:
– am
ylas
e br
eaks
dow
n st
arch
to
sim
pler
sug
ars
– pr
otea
se b
reak
s do
wn
prot
ein
to a
min
o ac
ids
– lip
ase
brea
ks d
own
fats
to
fatt
y ac
ids
and
glyc
erol
• S
tate
whe
re, i
n th
e al
imen
tary
ca
nal,
amyl
ase,
pro
teas
e an
d lip
ase
are
secr
eted
• S
tate
the
fun
ctio
ns o
f th
e hy
droc
hlor
ic a
cid
in g
astr
ic ju
ice,
lim
ited
to k
illin
g ba
cter
ia in
foo
d an
d gi
ving
an
acid
pH
for
enz
ymes
• D
escr
ibe
the
dige
stio
n of
st
arch
in t
he a
limen
tary
ca
nal:
– am
ylas
e is
sec
rete
d in
to t
he a
limen
tary
ca
nal a
nd b
reak
s do
wn
star
ch to
m
alto
se
– m
alto
se is
bro
ken
dow
n by
mal
tase
to
glu
cose
on
the
mem
bran
es o
f th
e ep
ithel
ium
lini
ng t
he
smal
l int
estin
e
• D
escr
ibe
peps
in a
nd
tryp
sin
as t
wo
prot
ease
en
zym
es t
hat
func
tion
in d
iffer
ent
part
s of
the
al
imen
tary
can
al:
– pe
psin
in t
he
stom
ach
– tr
ypsi
n in
the
sm
all
inte
stin
e
Section 4: What you need to know
49 Cambridge IGCSE Biology 0610
Top
icC
ore
mat
eria
l S
up
ple
men
t m
ater
ial
Yo
u s
ho
uld
be
able
to
: C
hec
klis
t C
om
men
ts
Yo
u s
ho
uld
be
able
to
: C
hec
klis
tC
om
men
ts
• E
xpla
in t
he f
unct
ions
of
the
hydr
ochl
oric
aci
d in
ga
stric
juic
e, li
mite
d to
th
e lo
w p
H:
– de
natu
ring
enzy
mes
in h
arm
ful
mic
roor
gani
sms
in
food
– gi
ving
the
opt
imum
pH
for p
epsi
n ac
tivity
• O
utlin
e th
e ro
le o
f bi
le
in n
eutr
alis
ing
the
acid
ic
mix
ture
of
food
and
ga
stric
juic
es e
nter
ing
the
duod
enum
fro
m t
he
stom
ach,
to
prov
ide
a su
itabl
e pH
for
enz
yme
actio
n
• O
utlin
e th
e ro
le o
f bi
le
in e
mul
sify
ing
fats
to
incr
ease
the
sur
face
ar
ea f
or t
he c
hem
ical
di
gest
ion
of f
at t
o fa
tty
acid
s an
d gl
ycer
ol b
y lip
ase
Section 4: What you need to know
50 Cambridge IGCSE Biology 0610
Top
icC
ore
mat
eria
l S
up
ple
men
t m
ater
ial
Yo
u s
ho
uld
be
able
to
: C
hec
klis
t C
om
men
ts
Yo
u s
ho
uld
be
able
to
: C
hec
klis
tC
om
men
ts
7.5
Abs
orpt
ion
• Id
entif
y th
e sm
all i
ntes
tine
as
the
regi
on f
or t
he a
bsor
ptio
n of
di
gest
ed f
ood
• S
tate
tha
t w
ater
is a
bsor
bed
in
both
the
sm
all i
ntes
tine
and
the
colo
n, b
ut t
hat
mos
t ab
sorp
tion
of w
ater
hap
pens
in t
he s
mal
l in
test
ine
• E
xpla
in t
he s
igni
fi can
ce
of v
illi a
nd m
icro
villi
in
incr
easi
ng t
he in
tern
al
surf
ace
area
of
the
smal
l in
test
ine
• D
escr
ibe
the
stru
ctur
e of
a
villu
s
• D
escr
ibe
the
role
s of
ca
pilla
ries
and
lact
eals
in
vill
i
8.
Tran
spo
rt in
pla
nts
8.1
Tran
spor
t in
pl
ants
• S
tate
the
fun
ctio
ns o
f xy
lem
and
ph
loem
• Id
entif
y th
e po
sitio
n of
xyl
em a
nd
phlo
em a
s se
en in
sec
tions
of
root
s, s
tem
s an
d le
aves
, lim
ited
to n
on-w
oody
dic
otyl
edon
ous
plan
ts
Section 4: What you need to know
51 Cambridge IGCSE Biology 0610
Top
icC
ore
mat
eria
l S
up
ple
men
t m
ater
ial
Yo
u s
ho
uld
be
able
to
: C
hec
klis
t C
om
men
ts
Yo
u s
ho
uld
be
able
to
: C
hec
klis
tC
om
men
ts
8.2
Wat
er u
ptak
e•
Iden
tify
root
hai
r ce
lls, a
s se
en
unde
r th
e lig
ht m
icro
scop
e, a
nd
stat
e th
eir
func
tions
• S
tate
the
pat
hway
tak
en b
y w
ater
th
roug
h ro
ot, s
tem
and
leaf
as
root
hai
r ce
ll, r
oot
cort
ex c
ells
, xy
lem
and
mes
ophy
ll ce
lls
• In
vest
igat
e, u
sing
a s
uita
ble
stai
n,
the
path
way
of
wat
er t
hrou
gh t
he
abov
e gr
ound
par
ts o
f a
plan
t
• E
xpla
in t
hat
the
larg
e su
rfac
e ar
ea o
f ro
ot h
airs
in
crea
ses
the
rate
of
the
abso
rptio
n of
wat
er
by o
smos
is a
nd io
ns b
y ac
tive
tran
spor
t
8.3
Tran
spira
tion
• S
tate
tha
t w
ater
is t
rans
port
ed
from
the
roo
ts t
o le
aves
thr
ough
th
e xy
lem
ves
sels
• D
efi n
e tr
ansp
iratio
n as
loss
of
wat
er v
apou
r fr
om p
lant
leav
es
by e
vapo
ratio
n of
wat
er a
t th
e su
rfac
es o
f th
e m
esop
hyll
cells
fo
llow
ed b
y di
ffus
ion
of w
ater
va
pour
thr
ough
the
sto
mat
a
• E
xpla
in h
ow w
ater
va
pour
loss
is r
elat
ed
to t
he la
rge
surf
ace
area
of
cell
surf
aces
, in
terc
onne
ctin
g ai
r sp
aces
and
sto
mat
a
• E
xpla
in t
he m
echa
nism
by
whi
ch w
ater
mov
es
upw
ards
in t
he x
ylem
in
term
s of
a t
rans
pira
tion
pull
that
dra
ws
up
a co
lum
n of
wat
er
mol
ecul
es, h
eld
toge
ther
by
coh
esio
n
Section 4: What you need to know
52 Cambridge IGCSE Biology 0610
Top
icC
ore
mat
eria
l S
up
ple
men
t m
ater
ial
Yo
u s
ho
uld
be
able
to
: C
hec
klis
t C
om
men
ts
Yo
u s
ho
uld
be
able
to
: C
hec
klis
tC
om
men
ts
• In
vest
igat
e an
d de
scrib
e th
e ef
fect
s of
var
iatio
n of
tem
pera
ture
an
d hu
mid
ity o
n tr
ansp
iratio
n ra
te
• E
xpla
in h
ow a
nd w
hy
wilt
ing
occu
rs
• E
xpla
in t
he e
ffec
ts o
f va
riatio
n of
tem
pera
ture
an
d hu
mid
ity o
n tr
ansp
iratio
n ra
te
8.4
Tran
sloc
atio
n•
Defi
ne
tran
sloc
atio
n in
te
rms
of t
he m
ovem
ent
of s
ucro
se a
nd a
min
o ac
ids
in p
hloe
m:
– fr
om re
gion
s of
pr
oduc
tion
(sou
rce)
– to
regi
ons
of s
tora
ge
OR
to re
gion
s w
here
th
ey a
re u
sed
in
resp
iratio
n or
gro
wth
(s
ink)
• E
xpla
in t
hat
som
e pa
rts
of a
pla
nt m
ay a
ct a
s a
sour
ce a
nd a
sin
k at
di
ffer
ent
times
dur
ing
the
life
of a
pla
nt
9.
Tran
spo
rt in
an
imal
s
9.1
Tran
spor
t in
an
imal
s•
Des
crib
e th
e ci
rcul
ator
y sy
stem
as
a s
yste
m o
f bl
ood
vess
els
with
a
pum
p an
d va
lves
to
ensu
re o
ne-
way
fl ow
of
bloo
d
• D
escr
ibe
the
sing
le
circ
ulat
ion
of a
fi sh
• D
escr
ibe
the
doub
le
circ
ulat
ion
of a
mam
mal
• E
xpla
in t
he a
dvan
tage
s of
a d
oubl
e ci
rcul
atio
n
Section 4: What you need to know
53 Cambridge IGCSE Biology 0610
Top
icC
ore
mat
eria
l S
up
ple
men
t m
ater
ial
Yo
u s
ho
uld
be
able
to
: C
hec
klis
t C
om
men
ts
Yo
u s
ho
uld
be
able
to
: C
hec
klis
tC
om
men
ts
9.2
Hea
rt•
Nam
e an
d id
entif
y th
e st
ruct
ures
of
the
mam
mal
ian
hear
t, li
mite
d to
the
mus
cula
r w
all,
the
sept
um,
the
left
and
rig
ht v
entr
icle
s an
d at
ria, o
ne-w
ay v
alve
s an
d co
rona
ry a
rter
ies
• S
tate
tha
t bl
ood
is p
umpe
d aw
ay
from
the
hea
rt in
to a
rter
ies
and
retu
rns
to t
he h
eart
in v
eins
• N
ame
and
iden
tify
the
atrio
vent
ricul
ar a
nd
sem
iluna
r va
lves
in t
he
mam
mal
ian
hear
t
• E
xpla
in t
he r
elat
ive
thic
knes
s:
– of
the
mus
cle
wal
l of
the
left
and
rig
ht
vent
ricle
s
– of
the
mus
cle
wal
l of
the
atria
com
pare
d to
tha
t of
the
ve
ntric
les
• E
xpla
in t
he im
port
ance
of
the
sept
um in
sep
arat
ing
oxyg
enat
ed a
nd
deox
ygen
ated
blo
od
• D
escr
ibe
the
func
tioni
ng
of t
he h
eart
in t
erm
s of
the
con
trac
tion
of
mus
cles
of
the
atria
and
ve
ntric
les
and
the
actio
n of
the
val
ves
Section 4: What you need to know
54 Cambridge IGCSE Biology 0610
Top
icC
ore
mat
eria
l S
up
ple
men
t m
ater
ial
Yo
u s
ho
uld
be
able
to
: C
hec
klis
t C
om
men
ts
Yo
u s
ho
uld
be
able
to
: C
hec
klis
tC
om
men
ts
• S
tate
tha
t th
e ac
tivity
of
the
hear
t m
ay b
e m
onito
red
by E
CG
, pul
se
rate
and
list
enin
g to
sou
nds
of
valv
es c
losi
ng
• In
vest
igat
e an
d st
ate
the
effe
ct o
f ph
ysic
al a
ctiv
ity o
n th
e pu
lse
rate
• D
escr
ibe
coro
nary
hea
rt d
isea
se
in t
erm
s of
the
blo
ckag
e of
co
rona
ry a
rter
ies
and
stat
e th
e po
ssib
le r
isk
fact
ors
as
diet
, str
ess,
sm
okin
g, g
enet
ic
pred
ispo
sitio
n, a
ge a
nd g
ende
r
• E
xpla
in t
he e
ffec
t of
ph
ysic
al a
ctiv
ity o
n th
e he
art
rate
• D
iscu
ss t
he r
oles
of
diet
and
exe
rcis
e in
the
pr
even
tion
of c
oron
ary
hear
t di
seas
e
• D
escr
ibe
way
s in
whi
ch
coro
nary
hea
rt d
isea
se
may
be
trea
ted,
lim
ited
to d
rug
trea
tmen
t w
ith
aspi
rin a
nd s
urge
ry
(ste
nts,
ang
iopl
asty
and
by
-pas
s)
9.3
Blo
od a
nd
lym
phat
ic
vess
els
• D
escr
ibe
the
stru
ctur
e an
d fu
nctio
ns o
f ar
terie
s, v
eins
and
ca
pilla
ries
• N
ame
the
mai
n bl
ood
vess
els
to
and
from
the
:
– he
art,
lim
ited
to v
ena
cava
, ao
rta,
pul
mon
ary
arte
ry a
nd
pulm
onar
y ve
in
– lu
ngs,
lim
ited
to t
he
pulm
onar
y ar
tery
and
pu
lmon
ary
vein
– ki
dney
, lim
ited
to t
he re
nal
arte
ry a
nd re
nal v
ein
• E
xpla
in h
ow t
he
stru
ctur
es o
f ar
terie
s,
vein
s an
d ca
pilla
ries
are
adap
ted
for
thei
r fu
nctio
ns
• S
tate
the
fun
ctio
n of
ar
terio
les,
ven
ules
and
sh
unt
vess
els
Section 4: What you need to know
55 Cambridge IGCSE Biology 0610
Top
icC
ore
mat
eria
l S
up
ple
men
t m
ater
ial
Yo
u s
ho
uld
be
able
to
: C
hec
klis
t C
om
men
ts
Yo
u s
ho
uld
be
able
to
: C
hec
klis
tC
om
men
ts
• O
utlin
e th
e ly
mph
atic
sy
stem
in t
erm
s of
ly
mph
atic
ves
sels
and
ly
mph
nod
es
• D
escr
ibe
the
func
tion
of
the
lym
phat
ic s
yste
m in
th
e ci
rcul
atio
n of
bod
y fl u
ids
and
the
prot
ectio
n of
the
bod
y fr
om
infe
ctio
n
9.4
Blo
od•
List
the
com
pone
nts
of b
lood
as
red
bloo
d ce
lls, w
hite
blo
od c
ells
, pl
atel
ets
and
plas
ma
• Id
entif
y re
d an
d w
hite
blo
od
cells
, as
seen
und
er t
he li
ght
mic
rosc
ope,
on
prep
ared
sl
ides
and
in d
iagr
ams
and
phot
omic
rogr
aphs
• S
tate
the
fun
ctio
ns o
f th
e fo
llow
ing
com
pone
nts
of b
lood
:
– re
d bl
ood
cells
in t
rans
port
ing
oxyg
en, i
nclu
ding
the
rol
e of
ha
emog
lobi
n
– w
hite
blo
od c
ells
in
phag
ocyt
osis
and
ant
ibod
y pr
oduc
tion
– pl
atel
ets
in c
lott
ing
(det
ails
ar
e n
ot
requ
ired)
– pl
asm
a in
the
tra
nspo
rt o
f bl
ood
cells
, ion
s, s
olub
le
nutr
ient
s, h
orm
ones
and
ca
rbon
dio
xide
• Id
entif
y ly
mph
ocyt
e an
d ph
agoc
yte
whi
te b
lood
ce
lls, a
s se
en u
nder
th
e lig
ht m
icro
scop
e,
on p
repa
red
slid
es
and
in d
iagr
ams
and
phot
omic
rogr
aphs
• S
tate
the
fun
ctio
ns o
f:
– ly
mph
ocyt
es –
an
tibod
y pr
oduc
tion
– ph
agoc
ytes
–
phag
ocyt
osis
• D
escr
ibe
the
proc
ess
of
clot
ting
as th
e co
nver
sion
of
fi br
inog
en t
o fi b
rin t
o fo
rm a
mes
h
• S
tate
the
rol
es o
f bl
ood
clot
ting
as p
reve
ntin
g bl
ood
loss
and
pre
vent
ing
the
entr
y of
pat
hoge
ns
Section 4: What you need to know
56 Cambridge IGCSE Biology 0610
Top
icC
ore
mat
eria
l S
up
ple
men
t m
ater
ial
Yo
u s
ho
uld
be
able
to
: C
hec
klis
t C
om
men
ts
Yo
u s
ho
uld
be
able
to
: C
hec
klis
tC
om
men
ts
• D
escr
ibe
the
tran
sfer
of
mat
eria
ls b
etw
een
capi
llarie
s an
d tis
sue
fl uid
(det
ails
of
the
rol
es o
f w
ater
pot
entia
l and
hy
dros
tatic
pre
ssur
e ar
e n
ot
requ
ired)
10.
Dis
ease
s an
d im
mu
nit
y
• D
efi n
e pa
thog
en a
s a
dise
ase-
caus
ing
orga
nism
• D
efi n
e tr
ansm
issi
ble
dise
ase
as
a di
seas
e in
whi
ch t
he p
atho
gen
can
be p
asse
d fr
om o
ne h
ost
to
anot
her
• S
tate
tha
t th
e pa
thog
en f
or a
tr
ansm
issi
ble
dise
ase
may
be
tran
smitt
ed e
ither
thr
ough
dire
ct
cont
act,
e.g
. thr
ough
blo
od o
r ot
her
body
fl ui
ds, o
r in
dire
ctly
, e.
g. f
rom
con
tam
inat
ed s
urfa
ces
or f
ood,
fro
m a
nim
als,
or
from
th
e ai
r
• S
tate
tha
t th
e bo
dy h
as d
efen
ces:
– m
echa
nica
l bar
riers
, lim
ited
to s
kin
and
hairs
in t
he n
ose
– ch
emic
al b
arrie
rs, l
imite
d to
m
ucus
and
sto
mac
h ac
id
– ce
lls, l
imite
d to
pha
gocy
tosi
s an
d an
tibod
y pr
oduc
tion
by
whi
te b
lood
cel
ls
– w
hich
can
be
enha
nced
by
vacc
inat
ion
• S
tate
tha
t an
tibod
ies
lock
on
to
antig
ens
lead
ing
to d
irect
des
truc
tion
of p
atho
gens
, or
mar
king
of
path
ogen
s fo
r de
stru
ctio
n by
ph
agoc
ytes
• E
xpla
in h
ow e
ach
path
ogen
has
its
own
antig
ens,
whi
ch h
ave
spec
ifi c
shap
es, s
o sp
ecifi
c an
tibod
ies
whi
ch
fi t t
he s
peci
fi c s
hape
s of
th
e an
tigen
s ar
e ne
eded
• D
efi n
e ac
tive
imm
unity
as
def
ence
aga
inst
a
path
ogen
by
antib
ody
prod
uctio
n in
the
bod
y
• E
xpla
in t
hat
activ
e im
mun
ity is
gai
ned
afte
r an
infe
ctio
n by
a
path
ogen
, or
by
vacc
inat
ion
Section 4: What you need to know
57 Cambridge IGCSE Biology 0610
Top
icC
ore
mat
eria
l S
up
ple
men
t m
ater
ial
Yo
u s
ho
uld
be
able
to
: C
hec
klis
t C
om
men
ts
Yo
u s
ho
uld
be
able
to
: C
hec
klis
tC
om
men
ts
• E
xpla
in t
he p
roce
ss o
f va
ccin
atio
n:
– ha
rmle
ss p
atho
gen
give
n w
hich
has
an
tigen
s
– an
tigen
s tr
igge
r an
im
mun
e re
spon
se b
y ly
mph
ocyt
es w
hich
pr
oduc
e an
tibod
ies
– m
emor
y ce
lls a
re
prod
uced
tha
t gi
ve
long
-ter
m im
mun
ity
• E
xpla
in t
he im
port
ance
of
hygi
enic
foo
d pr
epar
atio
n,
good
per
sona
l hyg
iene
, was
te
disp
osal
and
sew
age
trea
tmen
t in
co
ntro
lling
the
spr
ead
of d
isea
se
• E
xpla
in t
he r
ole
of
vacc
inat
ion
in c
ontr
ollin
g th
e sp
read
of
dise
ases
• E
xpla
in t
hat
pass
ive
imm
unity
is s
hort
-ter
m
defe
nce
agai
nst
a pa
thog
en b
y an
tibod
ies
acqu
ired
from
ano
ther
in
divi
dual
, e.g
. mot
her
to
infa
nt
• S
tate
tha
t m
emor
y ce
lls
are
not
prod
uced
in
pass
ive
imm
unity
• E
xpla
in t
he im
port
ance
of
pas
sive
imm
unity
for
br
east
-fed
infa
nts
• S
tate
tha
t so
me
dise
ases
are
cau
sed
by t
he im
mun
e sy
stem
ta
rget
ing
and
dest
royi
ng
body
cel
ls, l
imite
d to
Ty
pe 1
dia
bete
s
Section 4: What you need to know
58 Cambridge IGCSE Biology 0610
Top
icC
ore
mat
eria
l S
up
ple
men
t m
ater
ial
Yo
u s
ho
uld
be
able
to
: C
hec
klis
t C
om
men
ts
Yo
u s
ho
uld
be
able
to
: C
hec
klis
tC
om
men
ts
11.
Gas
exc
han
ge
in h
um
ans
• Li
st t
he f
eatu
res
of g
as e
xcha
nge
surf
aces
in h
uman
s, li
mite
d to
la
rge
surf
ace
area
, thi
n su
rfac
e,
good
blo
od s
uppl
y an
d go
od
vent
ilatio
n w
ith a
ir
• N
ame
and
iden
tify
the
lung
s,
diap
hrag
m, r
ibs,
inte
rcos
tal
mus
cles
, lar
ynx,
tra
chea
, br
onch
i, br
onch
iole
s, a
lveo
li an
d as
soci
ated
cap
illar
ies
• N
ame
and
iden
tify
the
inte
rnal
and
ext
erna
l in
terc
osta
l mus
cles
• S
tate
the
fun
ctio
ns o
f th
e ca
rtila
ge in
the
tra
chea
• E
xpla
in t
he r
ole
of t
he
ribs,
the
inte
rnal
and
ex
tern
al in
terc
osta
l m
uscl
es a
nd t
he
diap
hrag
m in
pro
duci
ng
volu
me
and
pres
sure
ch
ange
s in
the
tho
rax
lead
ing
to t
he v
entil
atio
n of
the
lung
s•
Sta
te t
he d
iffer
ence
s in
co
mpo
sitio
n be
twee
n in
spire
d an
d ex
pire
d ai
r, li
mite
d to
oxy
gen,
ca
rbon
dio
xide
and
wat
er v
apou
r
• U
se li
mew
ater
as
a te
st f
or
carb
on d
ioxi
de t
o in
vest
igat
e th
e di
ffer
ence
s in
com
posi
tion
betw
een
insp
ired
and
expi
red
air
• E
xpla
in t
he d
iffer
ence
s in
com
posi
tion
betw
een
insp
ired
and
expi
red
air
Section 4: What you need to know
59 Cambridge IGCSE Biology 0610
Top
icC
ore
mat
eria
l S
up
ple
men
t m
ater
ial
Yo
u s
ho
uld
be
able
to
: C
hec
klis
t C
om
men
ts
Yo
u s
ho
uld
be
able
to
: C
hec
klis
tC
om
men
ts
• In
vest
igat
e an
d de
scrib
e th
e ef
fect
s of
phy
sica
l act
ivity
on
rate
an
d de
pth
of b
reat
hing
• E
xpla
in t
he li
nk b
etw
een
phys
ical
act
ivity
and
ra
te a
nd d
epth
of
brea
thin
g in
ter
ms
of
the
incr
ease
d ca
rbon
di
oxid
e co
ncen
trat
ion
in t
he b
lood
, det
ecte
d by
the
bra
in, c
ausi
ng
an in
crea
sed
rate
of
brea
thin
g
• E
xpla
in t
he r
ole
of g
oble
t ce
lls, m
ucus
and
cili
ated
ce
lls in
pro
tect
ing
the
gas
exch
ange
sys
tem
fr
om p
atho
gens
and
pa
rtic
les
12.
Res
pir
atio
n
12.1
Res
pira
tion
• S
tate
the
use
s of
ene
rgy
in
the
body
of
hum
ans:
mus
cle
cont
ract
ion,
pro
tein
syn
thes
is,
cell
divi
sion
, act
ive
tran
spor
t,
grow
th, t
he p
assa
ge o
f ne
rve
impu
lses
and
the
mai
nten
ance
of
a co
nsta
nt b
ody
tem
pera
ture
• S
tate
tha
t re
spira
tion
invo
lves
the
ac
tion
of e
nzym
es in
cel
ls
Section 4: What you need to know
60 Cambridge IGCSE Biology 0610
Top
icC
ore
mat
eria
l S
up
ple
men
t m
ater
ial
Yo
u s
ho
uld
be
able
to
: C
hec
klis
t C
om
men
ts
Yo
u s
ho
uld
be
able
to
: C
hec
klis
tC
om
men
ts
12.2
Aer
obic
re
spira
tion
• D
efi n
e ae
robi
c re
spira
tion
as
the
chem
ical
rea
ctio
ns in
cel
ls
that
use
oxy
gen
to b
reak
dow
n nu
trie
nt m
olec
ules
to
rele
ase
ener
gy
• S
tate
the
wor
d eq
uatio
n fo
r ae
robi
c re
spira
tion
as
gluc
ose
+ o
xyge
n →
car
bon
diox
ide
+ w
ater
• In
vest
igat
e th
e up
take
of
oxyg
en
by r
espi
ring
orga
nism
s, s
uch
as
arth
ropo
ds a
nd g
erm
inat
ing
seed
s
• S
tate
the
bal
ance
d ch
emic
al e
quat
ion
for
aero
bic
resp
iratio
n as
C
6H12
O6 +
6O
2 →
6C
O2 +
6H
2O
• In
vest
igat
e th
e ef
fect
of
tem
pera
ture
on
the
rate
of
resp
iratio
n of
ge
rmin
atin
g se
eds
12.3
Ana
erob
ic
resp
iratio
n•
Defi
ne
anae
robi
c re
spira
tion
as t
he c
hem
ical
rea
ctio
ns in
ce
lls t
hat
brea
k do
wn
nutr
ient
m
olec
ules
to
rele
ase
ener
gy
with
out
usin
g ox
ygen
• S
tate
the
wor
d eq
uatio
ns f
or
anae
robi
c re
spira
tion
in m
uscl
es
durin
g vi
goro
us e
xerc
ise
(glu
cose
→ la
ctic
aci
d) a
nd t
he
mic
roor
gani
sm y
east
(glu
cose
→
alco
hol +
car
bon
diox
ide)
• S
tate
tha
t an
aero
bic
resp
iratio
n re
leas
es m
uch
less
ene
rgy
per
gluc
ose
mol
ecul
e th
an a
erob
ic
resp
iratio
n
• S
tate
the
bal
ance
d ch
emic
al e
quat
ion
for
anae
robi
c re
spira
ti on
in
the
mic
roor
gani
sm y
east
as
C6H
12O
6 →
2C2H
5OH
+ 2
CO
2
Section 4: What you need to know
61 Cambridge IGCSE Biology 0610
Top
icC
ore
mat
eria
l S
up
ple
men
t m
ater
ial
Yo
u s
ho
uld
be
able
to
: C
hec
klis
t C
om
men
ts
Yo
u s
ho
uld
be
able
to
: C
hec
klis
tC
om
men
ts
• S
tate
tha
t la
ctic
aci
d bu
ilds
up in
mus
cles
and
bl
ood
durin
g vi
goro
us
exer
cise
cau
sing
an
oxyg
en d
ebt
• O
utlin
e ho
w t
he o
xyge
n de
bt is
rem
oved
dur
ing
reco
very
, lim
ited
to:
– ae
robi
c re
spira
tion
of
lact
ic a
cid
in t
he li
ver
– co
ntin
uatio
n,
afte
r ex
erci
se, o
f fa
st h
eart
rat
e to
tr
ansp
ort
lact
ic
acid
in b
lood
fro
m
mus
cles
to t
he li
ver
– co
ntin
uatio
n, a
fter
ex
erci
se, o
f de
eper
br
eath
ing
supp
lyin
g ox
ygen
for
aero
bic
resp
iratio
n of
lact
ic
acid
Section 4: What you need to know
62 Cambridge IGCSE Biology 0610
Top
icC
ore
mat
eria
l S
up
ple
men
t m
ater
ial
Yo
u s
ho
uld
be
able
to
: C
hec
klis
t C
om
men
ts
Yo
u s
ho
uld
be
able
to
: C
hec
klis
tC
om
men
ts
13.
Exc
reti
on
in h
um
ans
• S
tate
tha
t ur
ea is
for
med
in t
he
liver
fro
m e
xces
s am
ino
acid
s
• S
tate
tha
t ca
rbon
dio
xide
is
excr
eted
thr
ough
the
lung
s
• S
tate
tha
t th
e ki
dney
s ex
cret
e ur
ea a
nd e
xces
s w
ater
and
sal
ts
• E
xpla
in t
hat
the
volu
me
and
conc
entr
atio
n of
urin
e pr
oduc
ed
is a
ffec
ted
by w
ater
inta
ke,
tem
pera
ture
and
exe
rcis
e
• Id
entif
y on
dra
win
gs, d
iagr
ams
and
imag
es, t
he u
rete
rs, b
ladd
er
and
uret
hra
• D
escr
ibe
the
role
of
the
liver
in t
he a
ssim
ilatio
n of
am
ino
acid
s by
co
nver
ting
them
to
prot
eins
, inc
ludi
ng
plas
ma
prot
eins
, e.g
. fi b
rinog
en
• D
efi n
e de
amin
atio
n as
the
rem
oval
of
the
nitr
ogen
-con
tain
ing
part
of
am
ino
acid
s to
for
m
urea
• E
xpla
in t
he n
eed
for
excr
etio
n, li
mite
d to
to
xici
ty o
f ur
ea a
nd
carb
on d
ioxi
de
• O
utlin
e th
e st
ruct
ure
of
the
kidn
ey, l
imite
d to
th
e co
rtex
, med
ulla
and
ur
eter
Section 4: What you need to know
63 Cambridge IGCSE Biology 0610
Top
icC
ore
mat
eria
l S
up
ple
men
t m
ater
ial
Yo
u s
ho
uld
be
able
to
: C
hec
klis
t C
om
men
ts
Yo
u s
ho
uld
be
able
to
: C
hec
klis
tC
om
men
ts
• O
utlin
e th
e st
ruct
ure
and
func
tioni
ng o
f a
kidn
ey
tubu
le, i
nclu
ding
:
– th
e ro
le o
f th
e gl
omer
ulus
in t
he
fi ltr
atio
n fr
om t
he
bloo
d of
wat
er,
gluc
ose,
ure
a an
d sa
lts
– th
e ro
le o
f th
e tu
bule
in
the
reab
sorp
tion
of a
ll of
the
glu
cose
, m
ost
of t
he w
ater
an
d so
me
salts
ba
ck in
to t
he b
lood
, le
adin
g to
the
co
ncen
trat
ion
of
urea
in t
he u
rine
as w
ell a
s lo
ss o
f ex
cess
wat
er a
nd
salts
(det
ails
of
thes
e pr
oces
ses
are
no
t re
quire
d)
• E
xpla
in d
ialy
sis
in t
erm
s of
sal
t ba
lanc
e, t
he
mai
nten
ance
of
gluc
ose
conc
entr
atio
n an
d th
e re
mov
al o
f ur
ea
• D
escr
ibe
the
use
of d
ialy
sis
in k
idne
y m
achi
nes
• D
iscu
ss t
he a
dvan
tage
s an
d di
sadv
anta
ges
of
kidn
ey t
rans
plan
ts,
com
pare
d w
ith d
ialy
sis
Section 4: What you need to know
64 Cambridge IGCSE Biology 0610
Top
icC
ore
mat
eria
l S
up
ple
men
t m
ater
ial
Yo
u s
ho
uld
be
able
to
: C
hec
klis
t C
om
men
ts
Yo
u s
ho
uld
be
able
to
: C
hec
klis
tC
om
men
ts
14.
Co
ord
inat
ion
an
d r
esp
on
se
14.1
Ner
vous
co
ntro
l in
hum
ans
• D
escr
ibe
a ne
rve
impu
lse
as a
n el
ectr
ical
sig
nal t
hat
pass
es a
long
ne
rve
cells
cal
led
neur
ones
• D
escr
ibe
the
hum
an n
ervo
us
syst
em in
ter
ms
of:
– th
e ce
ntra
l ner
vous
sys
tem
co
nsis
ting
of b
rain
and
spi
nal
cord
– th
e pe
riphe
ral n
ervo
us
syst
em
– co
ordi
natio
n an
d re
gula
tion
of
body
fun
ctio
ns
• Id
entif
y m
otor
(eff
ecto
r), r
elay
(c
onne
ctor
) and
sen
sory
neu
rone
s fr
om d
iagr
ams
• D
escr
ibe
a si
mpl
e re
fl ex
arc
in t
erm
s of
rec
epto
r, s
enso
ry
neur
one,
rel
ay n
euro
ne, m
otor
ne
uron
es a
nd e
ffec
tor
• D
escr
ibe
a re
fl ex
actio
n as
a
mea
ns o
f au
tom
atic
ally
an
d ra
pidl
y in
tegr
atin
g an
d co
ordi
natin
g st
imul
i with
the
re
spon
ses
of e
ffec
tors
(mus
cles
an
d gl
ands
)
• D
istin
guis
h be
twee
n vo
lunt
ary
and
invo
lunt
ary
actio
ns
Section 4: What you need to know
65 Cambridge IGCSE Biology 0610
Top
icC
ore
mat
eria
l S
up
ple
men
t m
ater
ial
Yo
u s
ho
uld
be
able
to
: C
hec
klis
t C
om
men
ts
Yo
u s
ho
uld
be
able
to
: C
hec
klis
tC
om
men
ts
• D
efi n
e a
syna
pse
as a
junc
tion
betw
een
two
neur
ones
• D
escr
ibe
the
stru
ctur
e of
a s
ynap
se, i
nclu
ding
th
e pr
esen
ce o
f ne
urot
rans
mitt
er
cont
aini
ng v
esic
les,
th
e sy
napt
ic c
left
an
d ne
urot
rans
mitt
er
rece
ptor
mol
ecul
es
• D
escr
ibe
how
an
impu
lse
trig
gers
the
rel
ease
of
a n
euro
tran
smitt
er
from
ves
icle
s in
to t
he
syna
ptic
gap
and
how
th
e ne
urot
rans
mitt
er
diff
uses
acr
oss
to b
ind
with
rec
epto
r m
olec
ules
, in
the
mem
bran
e of
th
e ne
uron
e af
ter
the
syna
ptic
gap
, cau
sing
the
im
puls
e to
con
tinue
• S
tate
tha
t in
a r
efl e
x ar
c th
e sy
naps
es e
nsur
e th
at
impu
lses
tra
vel i
n on
e di
rect
ion
only
• S
tate
tha
t m
any
drug
s,
e.g.
her
oin
act
upon
sy
naps
es
Section 4: What you need to know
66 Cambridge IGCSE Biology 0610
Top
icC
ore
mat
eria
l S
up
ple
men
t m
ater
ial
Yo
u s
ho
uld
be
able
to
: C
hec
klis
t C
om
men
ts
Yo
u s
ho
uld
be
able
to
: C
hec
klis
tC
om
men
ts
14.2
Sen
se o
rgan
s•
Defi
ne
sens
e or
gans
as
grou
ps
of r
ecep
tor
cells
res
pond
ing
to
spec
ifi c
stim
uli:
light
, sou
nd,
touc
h, t
empe
ratu
re a
nd c
hem
ical
s
• Id
entif
y th
e st
ruct
ures
of
the
eye,
lim
ited
to c
orne
a, ir
is, p
upil,
lens
, re
tina,
opt
ic n
erve
and
blin
d sp
ot
• D
escr
ibe
the
func
tion
of e
ach
part
of
the
eye
, lim
ited
to:
– co
rnea
– re
frac
ts li
ght
– iri
s –
cont
rols
how
muc
h lig
ht
ente
rs p
upil
– le
ns –
focu
ses
light
ont
o re
tina
– re
tina
– co
ntai
ns li
ght
rece
ptor
s, s
ome
sens
itive
to
light
of
diff
eren
t co
lour
s
– op
tic n
erve
– c
arrie
s im
puls
es
to t
he b
rain
• E
xpla
in t
he p
upil
refl e
x in
ter
ms
of
light
inte
nsity
and
pup
il di
amet
er
only
Section 4: What you need to know
67 Cambridge IGCSE Biology 0610
Top
icC
ore
mat
eria
l S
up
ple
men
t m
ater
ial
Yo
u s
ho
uld
be
able
to
: C
hec
klis
t C
om
men
ts
Yo
u s
ho
uld
be
able
to
: C
hec
klis
tC
om
men
ts
• E
xpla
in t
he p
upil
refl e
x in
ter
ms
of
light
inte
nsity
and
pup
il di
amet
er
only
• E
xpla
in t
he p
upil
refl e
x in
ter
ms
of li
ght
inte
nsity
an
d an
tago
nist
ic a
ctio
n of
circ
ular
and
rad
ial
mus
cles
in t
he ir
is
• E
xpla
in a
ccom
mod
atio
n to
vie
w n
ear
and
dist
ant
obje
cts
in t
erm
s of
th
e co
ntra
ctio
n an
d re
laxa
tion
of t
he c
iliar
y m
uscl
es, t
ensi
on in
the
su
spen
sory
liga
men
ts,
shap
e of
the
lens
and
re
frac
tion
of li
ght
• S
tate
the
dis
trib
utio
n of
ro
ds a
nd c
ones
in t
he
retin
a of
a h
uman
• O
utlin
e th
e fu
nctio
n of
ro
ds a
nd c
ones
, lim
ited
to g
reat
er s
ensi
tivity
of
rods
for
nig
ht v
isio
n an
d th
ree
diff
eren
t ki
nds
of
cone
s ab
sorb
ing
light
of
diff
eren
t co
lour
s fo
r co
lour
vis
ion
• Id
entif
y th
e po
sitio
n of
th
e fo
vea
Section 4: What you need to know
68 Cambridge IGCSE Biology 0610
Top
icC
ore
mat
eria
l S
up
ple
men
t m
ater
ial
Yo
u s
ho
uld
be
able
to
: C
hec
klis
t C
om
men
ts
Yo
u s
ho
uld
be
able
to
: C
hec
klis
tC
om
men
ts
14.3
Hor
mon
es in
hu
man
s•
Defi
ne
a ho
rmon
e as
a c
hem
ical
su
bsta
nce,
pro
duce
d by
a g
land
an
d ca
rrie
d by
the
blo
od, w
hich
al
ters
the
act
ivity
of
one
or m
ore
spec
ifi c
targ
et o
rgan
s
• Id
entif
y sp
ecifi
c en
docr
ine
glan
ds
and
thei
r se
cret
ions
, lim
ited
to
adre
nal g
land
s an
d ad
rena
line,
pa
ncre
as a
nd in
sulin
, tes
tes
and
test
oste
rone
and
ova
ries
and
oest
roge
n•
Des
crib
e ad
rena
line
as t
he
horm
one
secr
eted
in ‘fi
ght
or
fl igh
t’ s
ituat
ions
and
its
effe
cts,
lim
ited
to in
crea
sed
brea
thin
g an
d pu
lse
rate
and
wid
ened
pup
ils
• G
ive
exam
ples
of
situ
atio
ns
in w
hich
adr
enal
ine
secr
etio
n in
crea
ses
• S
tate
the
fun
ctio
ns o
f in
sulin
, oe
stro
gen
and
test
oste
rone
• D
iscu
ss t
he r
ole
of t
he
horm
one
adre
nalin
e in
th
e ch
emic
al c
ontr
ol
of m
etab
olic
act
ivity
, in
clud
ing
incr
easi
ng
the
bloo
d gl
ucos
e co
ncen
trat
ion
and
puls
e ra
te
• C
ompa
re n
ervo
us
and
horm
onal
con
trol
sy
stem
s in
ter
ms
of
spee
d an
d lo
ngev
ity o
f ac
tion
Section 4: What you need to know
69 Cambridge IGCSE Biology 0610
Top
icC
ore
mat
eria
l S
up
ple
men
t m
ater
ial
Yo
u s
ho
uld
be
able
to
: C
hec
klis
t C
om
men
ts
Yo
u s
ho
uld
be
able
to
: C
hec
klis
tC
om
men
ts
14.4
Hom
eost
asis
• D
efi n
e ho
meo
stas
is a
s th
e m
aint
enan
ce o
f a
cons
tant
in
tern
al e
nviro
nmen
t
• N
ame
and
iden
tify
on a
dia
gram
of
the
ski
n: h
airs
, hai
r er
ecto
r m
uscl
es, s
wea
t gla
nds,
rece
ptor
s,
sens
ory
neur
ones
, blo
od v
esse
ls
and
fatt
y tis
sue
• D
escr
ibe
the
mai
nten
ance
of
a c
onst
ant
inte
rnal
bod
y te
mpe
ratu
re in
hum
ans
in t
erm
s of
insu
latio
n, s
wea
ting,
shi
verin
g an
d th
e ro
le o
f th
e br
ain
(lim
ited
to b
lood
tem
pera
ture
rec
epto
rs
and
coor
dina
tion)
• E
xpla
in t
hat
hom
eost
asis
is
the
con
trol
of
inte
rnal
co
nditi
ons
with
in s
et
limits
• E
xpla
in t
he c
once
pt
of c
ontr
ol b
y ne
gativ
e fe
edba
ck
• D
escr
ibe
the
cont
rol
of t
he g
luco
se
conc
entr
atio
n of
the
bl
ood
by t
he li
ver
and
the
role
s of
insu
lin
and
gluc
agon
fro
m t
he
panc
reas
• O
utlin
e th
e sy
mpt
oms
and
trea
tmen
t of
Typ
e 1
diab
etes
(det
ail o
f β
cells
is
no
t re
quire
d)
• D
escr
ibe
the
mai
nten
ance
of
a co
nsta
nt in
tern
al b
ody
tem
pera
ture
in h
uman
s in
ter
ms
of v
asod
ilatio
n an
d va
soco
nstr
ictio
n of
ar
terio
les
supp
lyin
g sk
in
surf
ace
capi
llarie
s
Section 4: What you need to know
70 Cambridge IGCSE Biology 0610
Top
icC
ore
mat
eria
l S
up
ple
men
t m
ater
ial
Yo
u s
ho
uld
be
able
to
: C
hec
klis
t C
om
men
ts
Yo
u s
ho
uld
be
able
to
: C
hec
klis
tC
om
men
ts
14.5
Tro
pic
resp
onse
s•
Defi
ne
grav
itrop
ism
as
a re
spon
se
in w
hich
par
ts o
f a
plan
t gr
ow
tow
ards
or
away
fro
m g
ravi
ty
• D
efi n
e ph
otot
ropi
sm a
s a
resp
onse
in w
hich
par
ts o
f a
plan
t gr
ow t
owar
ds o
r aw
ay f
rom
th
e di
rect
ion
from
whi
ch li
ght
is
com
ing
• In
vest
igat
e gr
avitr
opis
m a
nd
phot
otro
pism
in s
hoot
s an
d ro
ots
• E
xpla
in p
hoto
trop
ism
an
d gr
avitr
opis
m o
f a
shoo
t as
exa
mpl
es o
f th
e ch
emic
al c
ontr
ol o
f pl
ant
grow
th
• E
xpla
in t
he r
ole
of a
uxin
in
con
trol
ling
shoo
t gr
owth
, lim
ited
to:
– au
xin
mad
e in
sho
ot
tip (o
nly)
– au
xin
spre
ads
thro
ugh
the
plan
t fr
om t
he s
hoot
tip
– au
xin
is u
nequ
ally
di
strib
uted
in
resp
onse
to li
ght
and
grav
ity
– au
xin
stim
ulat
es c
ell
elon
gatio
n
• D
escr
ibe
the
use
in
wee
dkill
ers
of t
he
synt
hetic
pla
nt h
orm
one
2,4-
D
15.
Dru
gs
15.1
Dru
gs•
Defi
ne
a dr
ug a
s an
y su
bsta
nce
take
n in
to t
he b
ody
that
mod
ifi es
or
aff
ects
che
mic
al r
eact
ions
in
the
body
Section 4: What you need to know
71 Cambridge IGCSE Biology 0610
Top
icC
ore
mat
eria
l S
up
ple
men
t m
ater
ial
Yo
u s
ho
uld
be
able
to
: C
hec
klis
t C
om
men
ts
Yo
u s
ho
uld
be
able
to
: C
hec
klis
tC
om
men
ts
15.2
Med
icin
al
drug
s•
Des
crib
e th
e us
e of
ant
ibio
tics
for
the
trea
tmen
t of
bac
teria
l in
fect
ion
• S
tate
tha
t so
me
bact
eria
are
re
sist
ant
to a
ntib
iotic
s w
hich
re
duce
s th
e ef
fect
iven
ess
of
antib
iotic
s
• S
tate
tha
t an
tibio
tics
kill
bact
eria
bu
t do
not
aff
ect
viru
ses
• E
xpla
in h
ow
deve
lopm
ent
of r
esis
tant
ba
cter
ia s
uch
as M
RS
A
can
be m
inim
ised
, lim
ited
to u
sing
ant
ibio
tics
only
w
hen
esse
ntia
l and
en
surin
g tr
eatm
ent
is
com
plet
ed
• E
xpla
in w
hy a
ntib
iotic
s ki
ll ba
cter
ia, b
ut d
o no
t af
fect
viru
ses
15.3
Mis
used
dru
gs•
Des
crib
e th
e ef
fect
s of
exc
essi
ve
alco
hol c
onsu
mpt
ion
and
abus
e of
he
roin
, lim
ited
to:
– po
wer
ful d
epre
ssan
t dr
ugs
– ef
fect
on
reac
tion
times
and
se
lf-co
ntro
l
– ad
dict
ion
and
with
draw
al
sym
ptom
s
– ne
gativ
e so
cial
impl
icat
ions
, e.
g. c
rime
• S
tate
tha
t in
ject
ing
hero
in c
an
caus
e in
fect
ions
suc
h as
HIV
• S
tate
tha
t ex
cess
ive
alco
hol
cons
umpt
ion
can
caus
e liv
er
dam
age
• E
xpla
in h
ow h
eroi
n af
fect
s th
e ne
rvou
s sy
stem
,lim
ited
to it
s ef
fect
on
the
func
tion
of s
ynap
ses
Section 4: What you need to know
72 Cambridge IGCSE Biology 0610
Top
icC
ore
mat
eria
l S
up
ple
men
t m
ater
ial
Yo
u s
ho
uld
be
able
to
: C
hec
klis
t C
om
men
ts
Yo
u s
ho
uld
be
able
to
: C
hec
klis
tC
om
men
ts
• S
tate
tha
t to
bacc
o sm
okin
g ca
n ca
use
chro
nic
obst
ruct
ive
pulm
onar
y di
seas
e (C
OP
D),
lung
ca
ncer
and
cor
onar
y he
art
dise
ase
• D
escr
ibe
the
effe
cts
on t
he g
as
exch
ange
sys
tem
of
toba
cco
smok
e an
d its
maj
or t
oxic
co
mpo
nent
s, li
mite
d to
car
bon
mon
oxid
e, n
icot
ine
and
tar
• S
tate
tha
t th
e liv
er is
the
site
of
brea
k do
wn
of a
lcoh
ol a
nd o
ther
to
xins
• D
iscu
ss t
he e
vide
nce
for
the
link
betw
een
smok
ing
and
lung
can
cer
• D
iscu
ss t
he u
se o
f ho
rmon
es t
o im
prov
e sp
ortin
g pe
rfor
man
ce,
limite
d to
tes
tost
eron
e an
d an
abol
ic s
tero
ids
16.
Rep
rod
uct
ion
16.1
Ase
xual
re
prod
uctio
n•
Defi
ne
asex
ual r
epro
duct
ion
as a
pro
cess
res
ultin
g in
the
pr
oduc
tion
of g
enet
ical
ly id
entic
al
offs
prin
g fr
om o
ne p
aren
t
• Id
entif
y ex
ampl
es o
f as
exua
l re
prod
uctio
n fr
om in
form
atio
n pr
ovid
ed•
Dis
cuss
the
adv
anta
ges
and
disa
dvan
tage
s of
as
exua
l rep
rodu
ctio
n:
– to
a p
opul
atio
n of
a
spec
ies
in t
he w
ild
– to
cro
p pr
oduc
tion
Section 4: What you need to know
73 Cambridge IGCSE Biology 0610
Top
icC
ore
mat
eria
l S
up
ple
men
t m
ater
ial
Yo
u s
ho
uld
be
able
to
: C
hec
klis
t C
om
men
ts
Yo
u s
ho
uld
be
able
to
: C
hec
klis
tC
om
men
ts
16.2
Sex
ual
repr
oduc
tion
• D
efi n
e se
xual
repr
oduc
tion
as a
pr
oces
s in
volv
ing
the
fusi
on o
f th
e nu
clei
of
two
gam
etes
(sex
ce
lls) t
o fo
rm a
zyg
ote
and
the
prod
uctio
n of
off
sprin
g th
at a
re
gene
tical
ly d
iffer
ent
from
eac
h ot
her
• D
efi n
e fe
rtili
satio
n as
the
fus
ion
of g
amet
e nu
clei
• S
tate
tha
t th
e nu
clei
of
gam
etes
are
hap
loid
and
th
at t
he n
ucle
us o
f a
zygo
te is
dip
loid
• D
iscu
ss t
he a
dvan
tage
s an
d di
sadv
anta
ges
of
sexu
al r
epro
duct
ion:
– to
a p
opul
atio
n of
a
spec
ies
in t
he w
ild
– to
cro
p pr
oduc
tion
16.3
Sex
ual
repr
oduc
tion
in
plan
ts
• Id
entif
y an
d dr
aw, u
sing
a h
and
lens
if n
eces
sary
, the
sep
als,
pe
tals
, sta
men
s, fi
lam
ents
and
an
ther
s, c
arpe
ls, s
tyle
, stig
ma,
ov
ary
and
ovul
es, o
f an
inse
ct-
polli
nate
d fl o
wer
• S
tate
the
fun
ctio
ns o
f th
e se
pals
, pe
tals
, ant
hers
, stig
mas
and
ov
arie
s
• U
se a
han
d le
ns t
o id
entif
y an
d de
scrib
e th
e an
ther
s an
d st
igm
as
of a
win
d-po
llina
ted
fl ow
er
• D
istin
guis
h be
twee
n th
e po
llen
grai
ns o
f in
sect
-pol
linat
ed a
nd w
ind-
polli
nate
d fl o
wer
s
Section 4: What you need to know
74 Cambridge IGCSE Biology 0610
Top
icC
ore
mat
eria
l S
up
ple
men
t m
ater
ial
Yo
u s
ho
uld
be
able
to
: C
hec
klis
t C
om
men
ts
Yo
u s
ho
uld
be
able
to
: C
hec
klis
tC
om
men
ts
• D
efi n
e po
llina
tion
as t
he t
rans
fer
of p
olle
n gr
ains
fro
m t
he a
nthe
r to
th
e st
igm
a
• D
efi n
e se
lf-po
llina
tion
as t
he t
rans
fer
of p
olle
n gr
ains
fro
m t
he a
nthe
r of
a fl
ower
to
the
stig
ma
of t
he s
ame
fl ow
er o
r di
ffer
ent
fl ow
er o
n th
e sa
me
plan
t
• D
efi n
e cr
oss-
polli
natio
n as
tra
nsfe
r of
pol
len
grai
ns f
rom
the
ant
her
of a
fl ow
er t
o th
e st
igm
a of
a fl
ower
on
a di
ffer
ent
plan
t of
the
sam
e sp
ecie
s
• D
iscu
ss t
he im
plic
atio
ns
to a
spe
cies
of
self-
polli
natio
n an
d cr
oss-
polli
natio
n in
ter
ms
of v
aria
tion,
cap
acity
to
resp
ond
to c
hang
es in
th
e en
viro
nmen
t an
d re
lianc
e on
pol
linat
ors
• S
tate
tha
t fe
rtili
satio
n oc
curs
w
hen
a po
llen
nucl
eus
fuse
s w
ith
a nu
cleu
s in
an
ovul
e
• D
escr
ibe
the
stru
ctur
al
adap
tatio
ns o
f in
sect
-pol
linat
ed a
nd w
ind-
polli
nate
d fl o
wer
s
• In
vest
igat
e an
d st
ate
the
envi
ronm
enta
l con
ditio
ns t
hat
affe
ct g
erm
inat
ion
of s
eeds
, lim
ited
to t
he r
equi
rem
ent
for
wat
er, o
xyge
n an
d a
suita
ble
tem
pera
ture
• D
escr
ibe
the
grow
th
of t
he p
olle
n tu
be a
nd
its e
ntry
into
the
ovu
le
follo
wed
by
fert
ilisa
tion
(det
ails
of
prod
uctio
n of
end
ospe
rm a
nd
deve
lopm
ent
are
no
t re
quire
d)
Section 4: What you need to know
75 Cambridge IGCSE Biology 0610
Top
icC
ore
mat
eria
l S
up
ple
men
t m
ater
ial
Yo
u s
ho
uld
be
able
to
: C
hec
klis
t C
om
men
ts
Yo
u s
ho
uld
be
able
to
: C
hec
klis
tC
om
men
ts
16.4
Sex
ual
repr
oduc
tion
in
hum
ans
• Id
entif
y an
d na
me
on d
iagr
ams
of t
he m
ale
repr
oduc
tive
syst
em:
the
test
es, s
crot
um, s
perm
duc
ts,
pros
tate
gla
nd, u
reth
ra a
nd p
enis
, an
d st
ate
the
func
tions
of
thes
e pa
rts
• Id
entif
y an
d na
me
on d
iagr
ams
of
the
fem
ale
repr
oduc
tive
syst
em:
the
ovar
ies,
ovi
duct
s, u
teru
s,
cerv
ix a
nd v
agin
a, a
nd s
tate
the
fu
nctio
ns o
f th
ese
part
s
• D
escr
ibe
fert
ilisa
tion
as t
he f
usio
n of
the
nuc
lei f
rom
a m
ale
gam
ete
(spe
rm) a
nd a
fem
ale
gam
ete
(egg
cel
l/ovu
m)
• C
ompa
re m
ale
and
fem
ale
gam
etes
in t
erm
s of
siz
e, s
truc
ture
, mot
ility
an
d nu
mbe
rs
• S
tate
the
ada
ptiv
e fe
atur
es o
f sp
erm
, lim
ited
to fl
agel
lum
and
th
e pr
esen
ce o
f en
zym
es
• S
tate
the
ada
ptiv
e fe
atur
es o
f eg
g ce
lls, l
imite
d to
ene
rgy
stor
es a
nd
a je
lly c
oatin
g th
at c
hang
es a
fter
fe
rtili
satio
n
• E
xpla
in t
he a
dapt
ive
feat
ures
of
sper
m,
limite
d to
fl ag
ellu
m,
mito
chon
dria
and
en
zym
es in
th
e ac
roso
me
• E
xpla
in t
he a
dapt
ive
feat
ures
of
egg
cells
, lim
ited
to e
nerg
y st
ores
an
d th
e je
lly c
oat
that
ch
ange
s at
fer
tilis
atio
n
Section 4: What you need to know
76 Cambridge IGCSE Biology 0610
Top
icC
ore
mat
eria
l S
up
ple
men
t m
ater
ial
Yo
u s
ho
uld
be
able
to
: C
hec
klis
t C
om
men
ts
Yo
u s
ho
uld
be
able
to
: C
hec
klis
tC
om
men
ts
• D
escr
ibe
the
ante
-nat
al c
are
of p
regn
ant
wom
en, l
imite
d to
sp
ecia
l die
tary
nee
ds a
nd t
he
harm
fro
m s
mok
ing
and
alco
hol
cons
umpt
ion
• O
utlin
e th
e pr
oces
ses
invo
lved
in
labo
ur a
nd b
irth,
lim
ited
to:
– br
eaki
ng o
f th
e am
niot
ic s
ac
– co
ntra
ctio
n of
the
mus
cles
in
the
uter
us w
all
– di
latio
n of
the
cer
vix
– pa
ssag
e th
roug
h th
e va
gina
– ty
ing
and
cutt
ing
the
umbi
lical
cor
d
– de
liver
y of
the
aft
erbi
rth
• D
iscu
ss t
he a
dvan
tage
s an
d di
sadv
anta
ges
of
brea
st-f
eedi
ng c
ompa
red
with
bot
tle-f
eedi
ng u
sing
fo
rmul
a m
ilk
16.5
Sex
hor
mon
es
in h
uman
s•
Des
crib
e th
e ro
les
of
test
oste
rone
and
oes
trog
en in
the
de
velo
pmen
t an
d re
gula
tion
of
seco
ndar
y se
xual
cha
ract
eris
tics
durin
g pu
bert
y
• D
escr
ibe
the
men
stru
al c
ycle
in
term
s of
cha
nges
in t
he o
varie
s an
d in
the
lini
ng o
f th
e ut
erus
• D
escr
ibe
the
site
s of
pr
oduc
tion
of o
estr
ogen
an
d pr
oges
tero
ne in
the
m
enst
rual
cyc
le a
nd in
pr
egna
ncy
• E
xpla
in t
he r
ole
of
horm
ones
in c
ontr
ollin
g th
e m
enst
rual
cyc
le a
nd
preg
nanc
y, li
mite
d to
FS
H, L
H, p
roge
ster
one
and
oest
roge
n
Section 4: What you need to know
77 Cambridge IGCSE Biology 0610
Top
icC
ore
mat
eria
l S
up
ple
men
t m
ater
ial
Yo
u s
ho
uld
be
able
to
: C
hec
klis
t C
om
men
ts
Yo
u s
ho
uld
be
able
to
: C
hec
klis
tC
om
men
ts
16.6
Met
hods
of
birt
h co
ntro
l in
hum
ans
• O
utlin
e th
e fo
llow
ing
met
hods
of
birt
h co
ntro
l:
– na
tura
l, lim
ited
to a
bstin
ence
, m
onito
ring
body
tem
pera
ture
an
d ce
rvic
al m
ucus
– ch
emic
al, l
imite
d to
IUD
, IU
S,
cont
race
ptiv
e pi
ll, im
plan
t an
d in
ject
ion
– ba
rrie
r, lim
ited
to c
ondo
m,
fem
idom
, dia
phra
gm
– su
rgic
al, l
imite
d to
vas
ecto
my
and
fem
ale
ster
ilisa
tion
• O
utlin
e th
e us
e of
hor
mon
es in
co
ntra
cept
ion
and
fert
ility
tr
eatm
ents
• O
utlin
e ar
tifi c
ial
inse
min
atio
n (A
I)
• O
utlin
e in
vitr
o fe
rtili
satio
n (IV
F)
• D
iscu
ss t
he s
ocia
l im
plic
atio
ns o
f co
ntra
cept
ion
and
fert
ility
tr
eatm
ents
16.7
Sex
ually
tr
ansm
itted
in
fect
ions
(S
TIs)
• D
efi n
e se
xual
ly tr
ansm
itted
in
fect
ion
as a
n in
fect
ion
that
is
tra
nsm
itted
via
bod
y fl u
ids
thro
ugh
sexu
al c
onta
ct
• S
tate
tha
t hu
man
im
mun
odefi
cie
ncy
viru
s (H
IV) i
s an
exa
mpl
e of
an
STI
• E
xpla
in h
ow t
he s
prea
d of
STI
s is
co
ntro
lled
• D
escr
ibe
the
met
hods
of
tran
smis
sion
of
HIV
• S
tate
tha
t H
IV in
fect
ion
may
lead
to
AID
S
• O
utlin
e ho
w H
IV a
ffec
ts
the
imm
une
syst
em,
limite
d to
dec
reas
ed
lym
phoc
yte
num
bers
an
d re
duce
d ab
ility
to
prod
uce
antib
odie
s
Section 4: What you need to know
78 Cambridge IGCSE Biology 0610
Top
icC
ore
mat
eria
l S
up
ple
men
t m
ater
ial
Yo
u s
ho
uld
be
able
to
: C
hec
klis
t C
om
men
ts
Yo
u s
ho
uld
be
able
to
: C
hec
klis
tC
om
men
ts
17.
Inh
erit
ance
17.1
Inhe
ritan
ce•
Defi
ne
inhe
ritan
ce a
s th
e tr
ansm
issi
on o
f ge
netic
in
form
atio
n fr
om g
ener
atio
n to
ge
nera
tion
17.2
Chr
omos
omes
, ge
nes
and
prot
eins
• D
efi n
e ch
rom
osom
e as
a t
hrea
d-lik
e st
ruct
ure
of D
NA
, car
ryin
g ge
netic
info
rmat
ion
in t
he f
orm
of
gene
s
• D
efi n
e ge
ne a
s a
leng
th o
f D
NA
th
at c
odes
for
a p
rote
in
• D
efi n
e al
lele
as
a ve
rsio
n of
a
gene
• D
escr
ibe
the
inhe
ritan
ce o
f se
x in
hu
man
s w
ith r
efer
ence
to
XX
and
X
Y c
hrom
osom
es
• E
xpla
in t
hat
the
sequ
ence
of
base
s in
a
gene
is t
he g
enet
ic
code
for
put
ting
toge
ther
am
ino
acid
s in
the
cor
rect
ord
er t
o m
ake
a sp
ecifi
c pr
otei
n (k
now
ledg
e of
the
det
ails
of
nuc
leot
ide
stru
ctur
e is
n
ot
requ
ired)
• E
xpla
in t
hat
DN
A
cont
rols
cel
l fun
ctio
n by
co
ntro
lling
the
pro
duct
ion
of p
rote
ins
(som
e of
w
hich
are
enz
ymes
), an
tibod
ies
and
rece
ptor
s fo
r ne
urot
rans
mitt
ers
Section 4: What you need to know
79 Cambridge IGCSE Biology 0610
Top
icC
ore
mat
eria
l S
up
ple
men
t m
ater
ial
Yo
u s
ho
uld
be
able
to
: C
hec
klis
t C
om
men
ts
Yo
u s
ho
uld
be
able
to
: C
hec
klis
tC
om
men
ts
• E
xpla
in h
ow a
pro
tein
is
mad
e, li
mite
d to
:
– th
e ge
ne c
odin
g fo
r th
e pr
otei
n re
mai
ns
in t
he n
ucle
us
– m
RN
A m
olec
ules
ca
rry
a co
py o
f th
e ge
ne to
the
cy
topl
asm
– th
e m
RN
A p
asse
s th
roug
h rib
osom
es
– th
e rib
osom
e as
sem
bles
am
ino
acid
s in
to p
rote
in
mol
ecul
es
– th
e sp
ecifi
c or
der
of a
min
o ac
ids
is d
eter
min
ed
by t
he s
eque
nce
of b
ases
in t
he
mR
NA
(kno
wle
dge
of t
he d
etai
ls o
f tr
ansc
riptio
n or
tr
ansl
atio
n is
no
t re
quire
d)
• E
xpla
in t
hat
all b
ody
cells
in a
n or
gani
sm
cont
ain
the
sam
e ge
nes,
bu
t m
any
gene
s in
a
part
icul
ar c
ell a
re n
ot
expr
esse
d be
caus
e th
e ce
ll on
ly m
akes
the
sp
ecifi
c pr
otei
ns it
nee
ds
Section 4: What you need to know
80 Cambridge IGCSE Biology 0610
Top
icC
ore
mat
eria
l S
up
ple
men
t m
ater
ial
Yo
u s
ho
uld
be
able
to
: C
hec
klis
t C
om
men
ts
Yo
u s
ho
uld
be
able
to
: C
hec
klis
tC
om
men
ts
• D
efi n
e a
hapl
oid
nucl
eus
as a
nuc
leus
con
tain
ing
a si
ngle
set
of
unpa
ired
chro
mos
omes
, e.g
. in
gam
etes
• D
efi n
e a
dipl
oid
nucl
eus
as a
nuc
leus
co
ntai
ning
tw
o se
ts o
f ch
rom
osom
es, e
.g. i
n bo
dy c
ells
• S
tate
tha
t in
a d
iplo
id c
ell,
ther
e is
a p
air
of e
ach
type
of
chro
mos
ome
and
in a
hum
an d
iplo
id c
ell
ther
e ar
e 23
pai
rs
17.3
Mito
sis
• D
efi n
e m
itosi
s as
nuc
lear
div
isio
n gi
ving
ris
e to
gen
etic
ally
iden
tical
ce
lls (d
etai
ls o
f st
ages
are
no
t re
quire
d)
• S
tate
the
rol
e of
mito
sis
in
grow
th, r
epai
r of
dam
aged
tis
sues
, rep
lace
men
t of
cel
ls a
nd
asex
ual r
epro
duct
ion
• S
tate
tha
t th
e ex
act
dupl
icat
ion
of
chro
mos
omes
occ
urs
befo
re m
itosi
s
• S
tate
tha
t du
ring
mito
sis,
the
cop
ies
of c
hrom
osom
es
sepa
rate
, mai
ntai
ning
the
ch
rom
osom
e nu
mbe
r (d
etai
ls o
f st
ages
of
mito
sis
are
no
t re
quire
d)
Section 4: What you need to know
81 Cambridge IGCSE Biology 0610
Top
icC
ore
mat
eria
l S
up
ple
men
t m
ater
ial
Yo
u s
ho
uld
be
able
to
: C
hec
klis
t C
om
men
ts
Yo
u s
ho
uld
be
able
to
: C
hec
klis
tC
om
men
ts
• D
escr
ibe
stem
cel
ls
as u
nspe
cial
ised
cel
ls
that
div
ide
by m
itosi
s to
pro
duce
dau
ghte
r ce
lls t
hat
can
beco
me
spec
ialis
ed f
or s
peci
fi c
func
tions
17.4
Mei
osis
• D
efi n
e m
eios
is a
s nu
clea
r di
visi
on
givi
ng r
ise
to c
ells
tha
t ar
e ge
netic
ally
diff
eren
t (d
etai
ls o
f st
ages
are
no
t re
quire
d)
• S
tate
tha
t m
eios
is is
invo
lved
in
the
prod
uctio
n of
gam
etes
• D
efi n
e m
eios
is a
s re
duct
ion
divi
sion
in
whi
ch t
he c
hrom
osom
e nu
mbe
r is
hal
ved
from
dip
loid
to
hapl
oid
resu
lting
in g
enet
ical
ly
diff
eren
t ce
lls (d
etai
ls o
f st
ages
are
no
t re
quire
d)
• E
xpla
in h
ow m
eios
is
prod
uces
var
iatio
n by
for
min
g ne
w
com
bina
tions
of
mat
erna
l and
pat
erna
l ch
rom
osom
es (s
peci
fi c
deta
ils a
re n
ot
requ
ired)
17.5
Mon
ohyb
rid
inhe
ritan
ce•
Defi
ne
geno
type
as
the
gene
tic
mak
e-up
of
an o
rgan
ism
in t
erm
s of
the
alle
les
pres
ent
• D
efi n
e ph
enot
ype
as t
he
obse
rvab
le f
eatu
res
of a
n or
gani
sm
• D
efi n
e ho
moz
ygou
s as
hav
ing
two
iden
tical
alle
les
of a
par
ticul
ar
gene
Section 4: What you need to know
82 Cambridge IGCSE Biology 0610
Top
icC
ore
mat
eria
l S
up
ple
men
t m
ater
ial
Yo
u s
ho
uld
be
able
to
: C
hec
klis
t C
om
men
ts
Yo
u s
ho
uld
be
able
to
: C
hec
klis
tC
om
men
ts
17.5
Mon
ohyb
rid
inhe
ritan
ce•
Sta
te t
hat
two
iden
tical
ho
moz
ygou
s in
divi
dual
s th
at
bree
d to
geth
er w
ill b
e pu
re-
bree
ding
• D
efi n
e he
tero
zygo
us a
s ha
ving
tw
o di
ffer
ent
alle
les
of a
par
ticul
ar
gene
• S
tate
tha
t a
hete
rozy
gous
in
divi
dual
will
not
be
pure
-br
eedi
ng
• D
efi n
e do
min
ant a
s an
alle
le t
hat
is e
xpre
ssed
if it
is p
rese
nt
• D
efi n
e re
cess
ive
as a
n al
lele
tha
t is
onl
y ex
pres
sed
whe
n th
ere
is
no d
omin
ant
alle
le o
f th
e ge
ne
pres
ent
• In
terp
ret
pedi
gree
dia
gram
s fo
r th
e in
herit
ance
of
a gi
ven
char
acte
ristic
• U
se g
enet
ic d
iagr
ams
to p
redi
ct
the
resu
lts o
f m
onoh
ybrid
cro
sses
an
d ca
lcul
ate
phen
otyp
ic r
atio
s,
limite
d to
1:1
and
3:1
rat
ios
• U
se P
unne
tt s
quar
es in
cro
sses
w
hich
res
ult
in m
ore
than
one
ge
noty
pe t
o w
ork
out
and
show
th
e po
ssib
le d
iffer
ent
geno
type
s
• E
xpla
in h
ow t
o us
e a
test
cro
ss t
o id
entif
y an
un
know
n ge
noty
pe
Section 4: What you need to know
83 Cambridge IGCSE Biology 0610
Top
icC
ore
mat
eria
l S
up
ple
men
t m
ater
ial
Yo
u s
ho
uld
be
able
to
: C
hec
klis
t C
om
men
ts
Yo
u s
ho
uld
be
able
to
: C
hec
klis
tC
om
men
ts
• E
xpla
in c
o-do
min
ance
by
ref
eren
ce t
o th
e in
herit
ance
of
AB
O b
lood
gr
oups
– p
heno
type
s be
ing
A, B
, AB
and
O
bloo
d gr
oups
and
alle
les
bein
g IA
, IB a
nd Io
• D
efi n
e a
sex-
linke
d ch
arac
teris
tic a
s a
char
acte
ristic
in w
hich
th
e ge
ne r
espo
nsib
le
is lo
cate
d on
a s
ex
chro
mos
ome
and
that
th
is m
akes
it m
ore
com
mon
in o
ne s
ex t
han
in t
he o
ther
• D
escr
ibe
colo
ur
blin
dnes
s as
an
exam
ple
of s
ex li
nkag
e
• U
se g
enet
ic d
iagr
ams
to p
redi
ct t
he r
esul
ts
of m
onoh
ybrid
cro
sses
in
volv
ing
co-d
omin
ance
or
sex
link
age
and
calc
ulat
e ph
enot
ypic
ra
tios
Section 4: What you need to know
84 Cambridge IGCSE Biology 0610
Top
icC
ore
mat
eria
l S
up
ple
men
t m
ater
ial
Yo
u s
ho
uld
be
able
to
: C
hec
klis
t C
om
men
ts
Yo
u s
ho
uld
be
able
to
: C
hec
klis
tC
om
men
ts
18.
Var
iati
on
an
d s
elec
tio
n
18.1
Var
iatio
n•
Defi
ne
varia
tion
as d
iffer
ence
s be
twee
n in
divi
dual
s of
the
sam
e sp
ecie
s
• D
istin
guis
h be
twee
n ph
enot
ypic
va
riatio
n an
d ge
netic
var
iatio
n
• S
tate
tha
t co
ntin
uous
var
iatio
n re
sults
in a
ran
ge o
f ph
enot
ypes
be
twee
n tw
o ex
trem
es, e
.g.
heig
ht in
hum
ans
• S
tate
tha
t di
scon
tinuo
us
varia
tion
resu
lts in
a li
mite
d nu
mbe
r of
phe
noty
pes
with
no
inte
rmed
iate
s, e
.g. t
ongu
e ro
lling
• R
ecor
d an
d pr
esen
t th
e re
sults
of
inve
stig
atio
ns in
to c
ontin
uous
and
di
scon
tinuo
us v
aria
tion
• D
efi n
e m
utat
ion
as g
enet
ic
chan
ge
• S
tate
tha
t m
utat
ion
is t
he w
ay in
w
hich
new
alle
les
are
form
ed
• S
tate
tha
t io
nisi
ng r
adia
tion
and
som
e ch
emic
als
incr
ease
the
rat
e of
mut
atio
n
• S
tate
tha
t ph
enot
ypic
va
riatio
n is
cau
sed
by b
oth
gene
tic a
nd
envi
ronm
enta
l fac
tors
• S
tate
tha
t di
scon
tinuo
us
varia
tion
is m
ostly
ca
used
by
gene
s al
one,
e.
g. A
, B, A
B a
nd O
bl
ood
grou
ps in
hum
ans
• D
efi n
e ge
ne m
utat
ion
as a
cha
nge
in t
he b
ase
sequ
ence
of
DN
A
Section 4: What you need to know
85 Cambridge IGCSE Biology 0610
Top
icC
ore
mat
eria
l S
up
ple
men
t m
ater
ial
Yo
u s
ho
uld
be
able
to
: C
hec
klis
t C
om
men
ts
Yo
u s
ho
uld
be
able
to
: C
hec
klis
tC
om
men
ts
• D
escr
ibe
the
sym
ptom
s of
sic
kle-
cell
anae
mia
• E
xpla
in h
ow a
cha
nge
in
the
base
seq
uenc
e of
the
ge
ne f
or h
aem
oglo
bin
resu
lts in
abn
orm
al
haem
oglo
bin
and
sick
le-
shap
ed r
ed b
lood
cel
ls
• U
se g
enet
ic d
iagr
ams
to s
how
how
sic
kle-
cell
anae
mia
is in
herit
ed
• S
tate
tha
t pe
ople
who
ar
e he
tero
zygo
us (H
bS
HbA
) for
the
sic
kle-
cell
alle
le h
ave
a re
sist
ance
to
mal
aria
• E
xpla
in t
he d
istr
ibut
ion
of t
he s
ickl
e-ce
ll al
lele
in
hum
an p
opul
atio
ns
with
ref
eren
ce t
o th
e di
strib
utio
n of
mal
aria
(Tea
chin
g of
hum
an in
herit
ed
cond
ition
s sh
ould
be
done
w
ith s
ensi
tivity
at
all t
imes
.)
Section 4: What you need to know
86 Cambridge IGCSE Biology 0610
Top
icC
ore
mat
eria
l S
up
ple
men
t m
ater
ial
Yo
u s
ho
uld
be
able
to
: C
hec
klis
t C
om
men
ts
Yo
u s
ho
uld
be
able
to
: C
hec
klis
tC
om
men
ts
18.2
Ada
ptiv
e fe
atur
es•
Defi
ne
adap
tive
feat
ure
as a
n in
herit
ed f
eatu
re t
hat
help
s an
org
anis
m t
o su
rviv
e an
d re
prod
uce
in it
s en
viro
nmen
t
• In
terp
ret
imag
es o
r ot
her
info
rmat
ion
abou
t a
spec
ies
to
desc
ribe
its a
dapt
ive
feat
ures
• D
efi n
e ad
aptiv
e fe
atur
e as
the
inhe
rited
fu
nctio
nal f
eatu
res
of a
n or
gani
sm t
hat
incr
ease
its
fi tn
ess
• D
efi n
e fi t
ness
as
the
prob
abili
ty o
f an
or
gani
sm s
urvi
ving
an
d re
prod
ucin
g in
the
en
viro
nmen
t in
whi
ch it
is
fou
nd
• E
xpla
in t
he a
dapt
ive
feat
ures
of
hydr
ophy
tes
and
xero
phyt
es t
o th
eir
envi
ronm
ents
18.3
Sel
ectio
n•
Des
crib
e na
tura
l sel
ectio
n w
ith
refe
renc
e to
:
– va
riatio
n w
ithin
pop
ulat
ions
– pr
oduc
tion
of m
any
offs
prin
g
– co
mpe
titio
n fo
r re
sour
ces
– st
rugg
le fo
r su
rviv
al
– re
prod
uctio
n by
indi
vidu
als
that
are
bet
ter
adap
ted
to t
he
envi
ronm
ent
than
oth
ers
– pa
ssin
g on
of
thei
r al
lele
s to
th
e ne
xt g
ener
atio
n
• D
escr
ibe
evol
utio
n as
th
e ch
ange
in a
dapt
ive
feat
ures
of
a po
pula
tion
over
tim
e as
the
res
ult
of
natu
ral s
elec
tion
• D
efi n
e th
e pr
oces
s of
ada
ptat
ion
as t
he
proc
ess,
res
ultin
g fr
om n
atur
al s
elec
tion,
by
whi
ch p
opul
atio
ns
beco
me
mor
e su
ited
to
thei
r en
viro
nmen
t ov
er
man
y ge
nera
tions
Section 4: What you need to know
87 Cambridge IGCSE Biology 0610
Top
icC
ore
mat
eria
l S
up
ple
men
t m
ater
ial
Yo
u s
ho
uld
be
able
to
: C
hec
klis
t C
om
men
ts
Yo
u s
ho
uld
be
able
to
: C
hec
klis
tC
om
men
ts
• D
escr
ibe
sele
ctiv
e br
eedi
ng w
ith
refe
renc
e to
:
– se
lect
ion
by h
uman
s of
in
divi
dual
s w
ith d
esira
ble
feat
ures
– cr
ossi
ng t
hese
indi
vidu
als
to
prod
uce
the
next
gen
erat
ion
– se
lect
ion
of o
ffsp
ring
show
ing
the
desi
rabl
e fe
atur
es
• D
escr
ibe
the
deve
lopm
ent
of s
trai
ns
of a
ntib
iotic
res
ista
nt
bact
eria
as
an e
xam
ple
of e
volu
tion
by n
atur
al
sele
ctio
n
• S
tate
the
diff
eren
ces
betw
een
natu
ral a
nd
artifi
cia
l sel
ectio
n
• O
utlin
e ho
w s
elec
tive
bree
ding
by
artifi
cia
l se
lect
ion
is c
arrie
d ou
t ov
er m
any
gene
ratio
ns t
o im
prov
e cr
op p
lant
s an
d do
mes
ticat
ed a
nim
als
19.
Org
anis
ms
and
th
eir
envi
ron
men
t
19.1
Ene
rgy
fl ow
• S
tate
tha
t th
e S
un is
the
prin
cipa
l so
urce
of
ener
gy in
put
to
biol
ogic
al s
yste
ms
• D
escr
ibe
the
fl ow
of
ener
gy t
hrou
gh li
ving
or
gani
sms
incl
udin
g lig
ht
ener
gy f
rom
the
sun
an
d ch
emic
al e
nerg
y in
org
anis
ms
and
its
even
tual
tra
nsfe
r to
the
en
viro
nmen
t
19.2
Foo
d ch
ains
an
d fo
od w
ebs
• D
efi n
e a
food
cha
in a
s sh
owin
g th
e tr
ansf
er o
f en
ergy
fro
m o
ne
orga
nism
to
the
next
, beg
inni
ng
with
a p
rodu
cer
Section 4: What you need to know
88 Cambridge IGCSE Biology 0610
Top
icC
ore
mat
eria
l S
up
ple
men
t m
ater
ial
Yo
u s
ho
uld
be
able
to
: C
hec
klis
t C
om
men
ts
Yo
u s
ho
uld
be
able
to
: C
hec
klis
tC
om
men
ts
• S
tate
tha
t en
ergy
is t
rans
ferr
ed
betw
een
orga
nism
s in
a f
ood
chai
n by
inge
stio
n
• C
onst
ruct
sim
ple
food
cha
ins
• D
escr
ibe
how
ene
rgy
is t
rans
ferr
ed b
etw
een
trop
hic
leve
ls
• D
efi n
e tr
ophi
c le
vel
as t
he p
ositi
on o
f an
or
gani
sm in
a f
ood
chai
n,
food
web
, pyr
amid
of
num
bers
or
pyra
mid
of
biom
ass
• E
xpla
in w
hy t
he t
rans
fer
of e
nerg
y fr
om o
ne
trop
hic
leve
l to
anot
her
is
inef
fi cie
nt
• E
xpla
in w
hy f
ood
chai
ns
usua
lly h
ave
few
er t
han
fi ve
trop
hic
leve
ls
• E
xpla
in w
hy t
here
is
a gr
eate
r ef
fi cie
ncy
in s
uppl
ying
pla
nts
as h
uman
foo
d, a
nd
that
the
re is
a r
elat
ive
inef
fi cie
ncy
in f
eedi
ng
crop
pla
nts
to li
vest
ock
that
will
be
used
as
food
• D
efi n
e a
food
web
as
a ne
twor
k of
inte
rcon
nect
ed f
ood
chai
ns
• D
efi n
e pr
oduc
er a
s an
org
anis
m
that
mak
es it
s ow
n or
gani
c nu
trie
nts,
usu
ally
usi
ng
ener
gy f
rom
sun
light
, thr
ough
ph
otos
ynth
esis
• D
efi n
e co
nsum
er a
s an
org
anis
m
that
get
s its
ene
rgy
by f
eedi
ng o
n ot
her
orga
nism
s
Section 4: What you need to know
89 Cambridge IGCSE Biology 0610
Top
icC
ore
mat
eria
l S
up
ple
men
t m
ater
ial
Yo
u s
ho
uld
be
able
to
: C
hec
klis
t C
om
men
ts
Yo
u s
ho
uld
be
able
to
: C
hec
klis
tC
om
men
ts
• S
tate
tha
t co
nsum
ers
may
be
clas
sed
as p
rimar
y, s
econ
dary
and
te
rtia
ry a
ccor
ding
to
thei
r po
sitio
n in
a f
ood
chai
n
• D
efi n
e he
rbiv
ore
as a
n an
imal
tha
t ge
ts it
s en
ergy
by
eatin
g pl
ants
• D
efi n
e ca
rniv
ore
as a
n an
imal
tha
t ge
ts it
s en
ergy
by
eatin
g ot
her
anim
als
• D
efi n
e de
com
pose
r as
an
orga
nism
tha
t ge
ts it
s en
ergy
fr
om d
ead
or w
aste
org
anic
m
ater
ial
• In
terp
ret
food
cha
ins
and
food
w
ebs
in t
erm
s of
iden
tifyi
ng
prod
ucer
s an
d co
nsum
ers
• U
se f
ood
chai
ns a
nd f
ood
web
s to
des
crib
e th
e im
pact
s hu
man
s ha
ve t
hrou
gh o
ver-
harv
estin
g of
foo
d sp
ecie
s an
d th
roug
h in
trod
ucin
g fo
reig
n sp
ecie
s to
a
habi
tat
• D
raw
, des
crib
e an
d in
terp
ret
pyra
mid
s of
num
bers
• Id
entif
y pr
oduc
ers,
pr
imar
y co
nsum
ers,
se
cond
ary
cons
umer
s,
tert
iary
con
sum
ers
and
quat
erna
ry c
onsu
mer
s as
the
tro
phic
leve
ls in
fo
od w
ebs,
foo
d ch
ains
, py
ram
ids
of n
umbe
rs a
nd
pyra
mid
s of
bio
mas
s
• D
raw
, des
crib
e an
d in
terp
ret
pyra
mid
s of
bi
omas
s
• D
iscu
ss t
he a
dvan
tage
s of
usi
ng a
pyr
amid
of
biom
ass
rath
er t
han
a py
ram
id o
f nu
mbe
rs t
o re
pres
ent
a fo
od c
hain
Section 4: What you need to know
90 Cambridge IGCSE Biology 0610
Top
icC
ore
mat
eria
l S
up
ple
men
t m
ater
ial
Yo
u s
ho
uld
be
able
to
: C
hec
klis
t C
om
men
ts
Yo
u s
ho
uld
be
able
to
: C
hec
klis
tC
om
men
ts
19.3
Nut
rient
cy
cles
• D
escr
ibe
the
carb
on c
ycle
, lim
ited
to p
hoto
synt
hesi
s, r
espi
ratio
n,
feed
ing,
dec
ompo
sitio
n,
foss
ilisa
tion
and
com
bust
ion
• D
iscu
ss t
he e
ffec
ts o
f th
e co
mbu
stio
n of
fos
sil f
uels
and
the
cu
ttin
g do
wn
of f
ores
ts o
n th
e ca
rbon
dio
xide
con
cent
ratio
ns in
th
e at
mos
pher
e
• D
escr
ibe
the
wat
er c
ycle
, lim
ited
to e
vapo
ratio
n, t
rans
pira
tion,
co
nden
satio
n an
d pr
ecip
itatio
n
• D
escr
ibe
the
nitr
ogen
cy
cle
in t
erm
s of
:
– de
com
posi
tion
of p
lant
and
an
imal
pro
tein
to
amm
oniu
m io
ns
– ni
trifi
catio
n
– ni
trog
en fi
xatio
n by
ligh
tnin
g an
d ba
cter
ia
– ab
sorp
tion
of n
itrat
e io
ns b
y pl
ants
– pr
oduc
tion
of a
min
o ac
ids
and
prot
eins
– fe
edin
g an
d di
gest
ion
of p
rote
ins
– de
amin
atio
n
– de
nitr
ifi ca
tion
Section 4: What you need to know
91 Cambridge IGCSE Biology 0610
Top
icC
ore
mat
eria
l S
up
ple
men
t m
ater
ial
Yo
u s
ho
uld
be
able
to
: C
hec
klis
t C
om
men
ts
Yo
u s
ho
uld
be
able
to
: C
hec
klis
tC
om
men
ts
• S
tate
the
rol
es o
f m
icro
orga
nism
s in
the
ni
trog
en c
ycle
, lim
ited
to d
ecom
posi
tion,
ni
trifi
catio
n, n
itrog
en
fi xat
ion
and
deni
trifi
catio
n (g
ener
ic n
ames
of
indi
vidu
al b
acte
ria,
e.g.
Rhi
zobi
um, a
re n
ot
requ
ired)
Section 4: What you need to know
92 Cambridge IGCSE Biology 0610
Top
icC
ore
mat
eria
l S
up
ple
men
t m
ater
ial
Yo
u s
ho
uld
be
able
to
: C
hec
klis
t C
om
men
ts
Yo
u s
ho
uld
be
able
to
: C
hec
klis
tC
om
men
ts
19.4
Pop
ulat
ion
size
• D
efi n
e po
pula
tion
as a
gro
up o
f or
gani
sms
of o
ne s
peci
es, l
ivin
g in
the
sam
e ar
ea, a
t th
e sa
me
time
• Id
entif
y an
d st
ate
the
fact
ors
affe
ctin
g th
e ra
te o
f po
pula
tion
grow
th f
or a
pop
ulat
ion
of a
n or
gani
sm, l
imite
d to
foo
d su
pply
, pr
edat
ion
and
dise
ase
• D
efi n
e co
mm
unity
as
all o
f th
e po
pula
tions
of
diff
eren
t sp
ecie
s in
an
ecos
yste
m
• D
efi n
e ec
osys
tem
as
a un
it co
ntai
ning
the
co
mm
unity
of
orga
nism
s an
d th
eir
envi
ronm
ent,
in
tera
ctin
g to
geth
er,
e.g.
a d
ecom
posi
ng lo
g,
or a
lake
• Id
entif
y th
e la
g,
expo
nent
ial (
log)
, st
atio
nary
and
dea
th
phas
es in
the
sig
moi
d po
pula
tion
grow
th c
urve
fo
r a
popu
latio
n gr
owin
g in
an
envi
ronm
ent
with
lim
ited
reso
urce
s
• E
xpla
in t
he f
acto
rs t
hat
lead
to
each
pha
se in
th
e si
gmoi
d cu
rve
of
popu
latio
n gr
owth
, m
akin
g re
fere
nce,
whe
re
appr
opria
te, t
o th
e ro
le o
f lim
iting
fac
tors
Section 4: What you need to know
93 Cambridge IGCSE Biology 0610
Top
icC
ore
mat
eria
l S
up
ple
men
t m
ater
ial
Yo
u s
ho
uld
be
able
to
: C
hec
klis
t C
om
men
ts
Yo
u s
ho
uld
be
able
to
: C
hec
klis
tC
om
men
ts
• D
iscu
ss t
he in
crea
se in
hum
an
popu
latio
n si
ze o
ver
the
past
25
0 ye
ars
and
its s
ocia
l and
en
viro
nmen
tal i
mpl
icat
ions
• In
terp
ret
grap
hs a
nd d
iagr
ams
of
hum
an p
opul
atio
n gr
owth
20.
Bio
tech
no
log
y an
d g
enet
ic e
ng
inee
rin
g
20.1
Bio
tech
nolo
gy
and
gene
tic
engi
neer
ing
• S
tate
tha
t ba
cter
ia a
re u
sefu
l in
bio
tech
nolo
gy a
nd g
enet
ic
engi
neer
ing
due
to t
heir
rapi
d re
prod
uctio
n ra
te a
nd t
heir
abili
ty
to m
ake
com
plex
mol
ecul
es
• D
iscu
ss w
hy b
acte
ria a
re
usef
ul in
bio
tech
nolo
gy
and
gene
tic e
ngin
eerin
g,
limite
d to
:
– la
ck o
f et
hica
l co
ncer
ns o
ver
thei
r m
anip
ulat
ion
and
grow
th
– ge
netic
cod
e sh
ared
w
ith a
ll ot
her
orga
nism
s
– pr
esen
ce o
f pl
asm
ids
20.2
Bio
tech
nolo
gy•
Des
crib
e th
e ro
le o
f an
aero
bic
resp
iratio
n in
yea
st d
urin
g pr
oduc
tion
of e
than
ol f
or b
iofu
els
• D
escr
ibe
the
role
of
anae
robi
c re
spira
tion
in y
east
dur
ing
brea
d-m
akin
g
• In
vest
igat
e an
d de
scrib
e th
e us
e of
pec
tinas
e in
fru
it ju
ice
prod
uctio
n
• In
vest
igat
e an
d de
scrib
e th
e us
e of
bio
logi
cal w
ashi
ng p
owde
rs
that
con
tain
enz
ymes
Section 4: What you need to know
94 Cambridge IGCSE Biology 0610
Top
icC
ore
mat
eria
l S
up
ple
men
t m
ater
ial
Yo
u s
ho
uld
be
able
to
: C
hec
klis
t C
om
men
ts
Yo
u s
ho
uld
be
able
to
: C
hec
klis
tC
om
men
ts
• In
vest
igat
e an
d ex
plai
n th
e us
e of
lact
ase
to
prod
uce
lact
ose-
free
milk
• D
escr
ibe
the
role
of
the
fung
us P
enic
illiu
m in
th
e pr
oduc
tion
of t
he
antib
iotic
pen
icill
in
• E
xpla
in h
ow f
erm
ente
rs
are
used
in t
he
prod
uctio
n of
pen
icill
in
20.3
Gen
etic
en
gine
erin
g•
Defi
ne
gene
tic e
ngin
eerin
g as
ch
angi
ng t
he g
enet
ic m
ater
ial
of a
n or
gani
sm b
y re
mov
ing,
ch
angi
ng o
r in
sert
ing
indi
vidu
al
gene
s
• S
tate
exa
mpl
es o
f ge
netic
en
gine
erin
g:
– th
e in
sert
ion
of h
uman
gen
es
into
bac
teria
to p
rodu
ce
hum
an in
sulin
– th
e in
sert
ion
of g
enes
in
to c
rop
plan
ts to
con
fer
resi
stan
ce to
her
bici
des
– th
e in
sert
ion
of g
enes
in
to c
rop
plan
ts to
con
fer
resi
stan
ce to
inse
ct p
ests
– th
e in
sert
ion
of g
enes
in
to c
rop
plan
ts to
pro
vide
ad
ditio
nal v
itam
ins
• O
utlin
e ge
netic
en
gine
erin
g us
ing
bact
eria
l pro
duct
ion
of
a hu
man
pro
tein
as
an
exam
ple,
lim
ited
to:
– is
olat
ion
of t
he
DN
A m
akin
g up
a
hum
an g
ene
usin
g re
stric
tion
enzy
mes
, fo
rmin
g st
icky
end
s
– cu
ttin
g of
bac
teria
l pl
asm
id D
NA
with
th
e sa
me
rest
rictio
n en
zym
es, f
orm
ing
com
plem
enta
ry
stic
ky e
nds
– in
sert
ion
of h
uman
D
NA
into
bac
teria
l pl
asm
id D
NA
usi
ng
DN
A li
gase
to fo
rm a
re
com
bina
nt p
lasm
id
Section 4: What you need to know
95 Cambridge IGCSE Biology 0610
Top
icC
ore
mat
eria
l S
up
ple
men
t m
ater
ial
Yo
u s
ho
uld
be
able
to
: C
hec
klis
t C
om
men
ts
Yo
u s
ho
uld
be
able
to
: C
hec
klis
tC
om
men
ts
– in
sert
ion
of p
lasm
id
into
bac
teria
(s
peci
fi c d
etai
l is
no
t re
quire
d)
– re
plic
atio
n of
ba
cter
ia c
onta
inin
g re
com
bina
nt
plas
mid
s w
hich
m
ake
hum
an p
rote
in
as t
hey
expr
ess
the
gene
• D
iscu
ss t
he a
dvan
tage
s an
d di
sadv
anta
ges
of
gene
tical
ly m
odify
ing
crop
s, s
uch
as s
oya,
m
aize
and
ric
e
21.
Hu
man
infl
uen
ces
on
eco
syst
ems
21.1
Foo
d su
pply
• S
tate
how
mod
ern
tech
nolo
gy
has
resu
lted
in in
crea
sed
food
pr
oduc
tion
in t
erm
s of
:
– ag
ricul
tura
l mac
hine
ry to
us
e la
rger
are
as o
f la
nd a
nd
impr
ove
effi c
ienc
y
– ch
emic
al fe
rtili
sers
to
impr
ove
yiel
ds
– in
sect
icid
es to
impr
ove
qual
ity a
nd y
ield
– he
rbic
ides
to re
duce
co
mpe
titio
n w
ith w
eeds
– se
lect
ive
bree
ding
to im
prov
e pr
oduc
tion
by c
rop
plan
ts a
nd
lives
tock
, e.g
. cat
tle, fi
sh
and
poul
try
• D
iscu
ss t
he s
ocia
l, en
viro
nmen
tal a
nd
econ
omic
impl
icat
ions
of
prov
idin
g su
ffi c
ient
foo
d fo
r an
incr
easi
ng h
uman
gl
obal
pop
ulat
ion
• D
iscu
ss t
he p
robl
ems
whi
ch c
ontr
ibut
e to
fa
min
e in
clud
ing
uneq
ual
dist
ribut
ion
of f
ood,
dr
ough
t an
d fl o
odin
g,
incr
easi
ng p
opul
atio
n an
d po
vert
y
Section 4: What you need to know
96 Cambridge IGCSE Biology 0610
Top
icC
ore
mat
eria
l S
up
ple
men
t m
ater
ial
Yo
u s
ho
uld
be
able
to
: C
hec
klis
t C
om
men
ts
Yo
u s
ho
uld
be
able
to
: C
hec
klis
tC
om
men
ts
• D
escr
ibe
the
nega
tive
impa
cts
to a
n ec
osys
tem
of
larg
e-sc
ale
mon
ocul
ture
s of
cro
p pl
ants
• D
escr
ibe
the
nega
tive
impa
cts
to a
n ec
osys
tem
of
inte
nsiv
e liv
esto
ck p
rodu
ctio
n
21.2
Hab
itat
dest
ruct
ion
• D
escr
ibe
the
reas
ons
for
habi
tat
dest
ruct
ion,
lim
ited
to:
– in
crea
sed
area
for
food
cro
p gr
owth
, liv
esto
ck p
rodu
ctio
n an
d ho
usin
g
– ex
trac
tion
of n
atur
al
reso
urce
s
– m
arin
e po
llutio
n
• S
tate
tha
t th
roug
h al
terin
g fo
od
web
s an
d fo
od c
hain
s, h
uman
s ca
n ha
ve a
neg
ativ
e im
pact
on
habi
tats
• Li
st t
he u
ndes
irabl
e ef
fect
s of
de
fore
stat
ion
as a
n ex
ampl
e of
ha
bita
t de
stru
ctio
n, t
o in
clud
e ex
tinct
ion,
loss
of
soil,
fl oo
ding
an
d in
crea
se o
f ca
rbon
dio
xide
in
the
atm
osph
ere
• E
xpla
in t
he u
ndes
irabl
e ef
fect
s of
def
ores
tatio
n on
the
env
ironm
ent
21.3
Pol
lutio
n•
Sta
te t
he s
ourc
es a
nd e
ffec
ts
of p
ollu
tion
of la
nd a
nd w
ater
, e.
g. r
iver
s, la
kes
and
the
sea,
by
inse
ctic
ides
, her
bici
des
and
by
nucl
ear
fall-
out
Section 4: What you need to know
97 Cambridge IGCSE Biology 0610
Top
icC
ore
mat
eria
l S
up
ple
men
t m
ater
ial
Yo
u s
ho
uld
be
able
to
: C
hec
klis
t C
om
men
ts
Yo
u s
ho
uld
be
able
to
: C
hec
klis
tC
om
men
ts
• S
tate
the
sou
rces
and
eff
ects
of
pollu
tion
of w
ater
(riv
ers,
lake
s an
d th
e se
a) b
y ch
emic
al w
aste
, di
scar
ded
rubb
ish,
unt
reat
ed
sew
age
and
fert
ilise
rs
• S
tate
the
sou
rces
and
eff
ects
of
pollu
tion
of t
he a
ir by
met
hane
an
d ca
rbon
dio
xide
, lim
ited
to t
he
enha
nced
gre
enho
use
effe
ct a
nd
clim
ate
chan
ge
• E
xpla
in t
he p
roce
ss o
f eu
trop
hica
tion
of w
ater
in
ter
ms
of:
– in
crea
sed
avai
labi
lity
of n
itrat
e an
d ot
her
ions
– in
crea
sed
grow
th o
f pr
oduc
ers
– in
crea
sed
deco
mpo
sitio
n af
ter
deat
h of
pro
duce
rs
– in
crea
sed
aero
bic
resp
iratio
n by
de
com
pose
rs
– re
duct
ion
in
diss
olve
d ox
ygen
– de
ath
of o
rgan
ism
s re
quiri
ng d
isso
lved
ox
ygen
in w
ater
• D
iscu
ss t
he e
ffec
ts
of n
on-b
iode
grad
able
pl
astic
s in
the
en
viro
nmen
t, in
bot
h aq
uatic
and
ter
rest
rial
ecos
yste
ms
Section 4: What you need to know
98 Cambridge IGCSE Biology 0610
Top
icC
ore
mat
eria
l S
up
ple
men
t m
ater
ial
Yo
u s
ho
uld
be
able
to
: C
hec
klis
t C
om
men
ts
Yo
u s
ho
uld
be
able
to
: C
hec
klis
tC
om
men
ts
• D
iscu
ss t
he c
ause
s an
d ef
fect
s on
the
en
viro
nmen
t of
aci
d ra
in
• S
tate
the
mea
sure
s th
at a
re t
aken
to
redu
ce
sulfu
r di
oxid
e po
llutio
n an
d re
duce
the
impa
ct o
f ac
id r
ain
• E
xpla
in h
ow in
crea
ses
in c
arbo
n di
oxid
e an
d m
etha
ne c
once
ntra
tions
in
the
atm
osph
ere
caus
e an
enh
ance
d gr
eenh
ouse
ef
fect
tha
t le
ads
to
clim
ate
chan
ge
• D
escr
ibe
the
nega
tive
impa
cts
of f
emal
e co
ntra
cept
ive
horm
ones
in
wat
er c
ours
es, l
imite
d to
red
uced
spe
rm c
ount
in
men
and
fem
inis
atio
n of
aqu
atic
org
anis
ms
21.4
Con
serv
atio
n•
Defi
ne
a su
stai
nabl
e re
sour
ce
as o
ne w
hich
is p
rodu
ced
as
rapi
dly
as it
is r
emov
ed f
rom
the
en
viro
nmen
t so
tha
t it
does
not
ru
n ou
t
• E
xpla
in t
he n
eed
to c
onse
rve
non-
rene
wab
le r
esou
rces
, lim
ited
to
foss
il fu
els
• D
efi n
e th
e te
rm
sust
aina
ble
deve
lopm
ent
as d
evel
opm
ent
prov
idin
g fo
r th
e ne
eds
of a
n in
crea
sing
hum
an
popu
latio
n w
ithou
t ha
rmin
g th
e en
viro
nmen
t
Section 4: What you need to know
99 Cambridge IGCSE Biology 0610
Top
icC
ore
mat
eria
l S
up
ple
men
t m
ater
ial
Yo
u s
ho
uld
be
able
to
: C
hec
klis
t C
om
men
ts
Yo
u s
ho
uld
be
able
to
: C
hec
klis
tC
om
men
ts
• S
tate
tha
t so
me
reso
urce
s ca
n be
m
aint
aine
d, li
mite
d to
for
ests
and
fi s
h st
ocks
• S
tate
tha
t pr
oduc
ts c
an b
e re
used
or
rec
ycle
d, li
mite
d to
pap
er,
glas
s, p
last
ic a
nd m
etal
• O
utlin
e ho
w s
ewag
e is
tre
ated
to
mak
e th
e w
ater
tha
t it
cont
ains
sa
fe t
o re
turn
to
the
envi
ronm
ent
or f
or h
uman
use
• E
xpla
in w
hy o
rgan
ism
s be
com
e en
dang
ered
or
extin
ct, l
imite
d to
clim
ate
chan
ge, h
abita
t de
stru
ctio
n, h
untin
g, p
ollu
tion
and
intr
oduc
ed s
peci
es
• D
escr
ibe
how
end
ange
red
spec
ies
can
be c
onse
rved
, lim
ited
to m
onito
ring
and
prot
ectin
g sp
ecie
s an
d ha
bita
ts, e
duca
tion,
ca
ptiv
e br
eedi
ng p
rogr
amm
es a
nd
seed
ban
ks
• E
xpla
in h
ow f
ores
ts
and
fi sh
stoc
ks c
an
be s
usta
ined
usi
ng
educ
atio
n, le
gal q
uota
s an
d re
-sto
ckin
g
• E
xpla
in t
hat
sust
aina
ble
deve
lopm
ent
requ
ires:
– m
anag
emen
t of
co
nfl ic
ting
dem
ands
– pl
anni
ng a
nd
co-o
pera
tion
at
loca
l, na
tiona
l and
in
tern
atio
nal l
evel
s
• E
xpla
in t
he r
isks
to
a sp
ecie
s if
the
popu
latio
n si
ze d
rops
, red
ucin
g va
riatio
n (k
now
ledg
e of
gen
etic
drif
t is
no
t re
quire
d)
• E
xpla
in r
easo
ns
for
cons
erva
tion
prog
ram
mes
, to
incl
ude:
– re
duci
ng e
xtin
ctio
n
– pr
otec
ting
vuln
erab
le
envi
ronm
ents
– m
aint
aini
ng
ecos
yste
m
func
tions
, lim
ited
to
nutr
ient
cyc
ling
and
reso
urce
pro
visi
on,
e.g.
food
, dru
gs, f
uel
and
gene
s
Section 4: What you need to know
100 Cambridge IGCSE Biology 0610
Section 5: Useful websites
101 Cambridge IGCSE Biology 0610
Section 5: Useful websites
These websites are useful resources to help you study for your Biology IGCSE.
www.bbc.co.uk/schools/gcsebitesize/biology A secondary revision source for GCSE examinations. The site contains revision material, tests and SOS teacher. The site also gives references to other relevant websites.
www.clickbiology.com/igcse-biology-2/A number of videos, animations and games for revision resources for IGCSE Biology.
www.skoool.com/You will need to select your location before accessing this revision site. There are numerous quizzes on topics, but like with many general revision sites, check which topics match the Cambridge IGCSE syllabus.
www.s-cool.co.uk A revision guide that can be used to complement your learning.
purchon.com/biology/revision.htm This website has information about revising and lots of useful resources about GCSE Biology which are also are relevant to IGCSE.
revisioncentral.co.uk/gcse/biology/index.html There are lots of Biology revision notes on this website including notes on Classifi cation, Cells, Tissues and Organs and Transportation in Plants.
revisionlink.co.uk/biology/index.html This site is a portal to lots of useful Biology and other educational web sites.
www.abpischools.org.uk/The Association of the British Pharmaceutical Industry (ABPI) has a numer of useful interactive revision activities and games on many of the physiology topics. Revision for human physiology.
Appsitunes.apple.com/gb/app/biology-gcse-revision/id367827149?mt=8These are new resources which are being developed.• Ipad:
www.educationapps.co.uk/ipad/revisionguide/gcse/biology/• Android:
www.educationapps.co.uk/apps/android/gcse/science/biology-revision• iphone:
www.educationapps.co.uk/apps/iphone/self-assessment/gcse/biology
Section 5: Useful websites
102 Cambridge IGCSE Biology 0610
Section 6: Appendices
103 Cambridge IGCSE Biology 0610
Section 6: Appendices
Mathematical skillsThis is a checklist of the mathematical skills you need for your Biology examination. You should tick each box in the checklist when you know that you have learned the skill. Ask your teacher to explain any skill you are unsure about. The ‘Comments’ column is for extra notes and examples.
You can use a calculator for all the examination papers. If your calculator is one that can be programmed, you should make sure that any information in it is removed before the examination.
You should be able: Checklist Comments
• add
• subtract
• multiply
• divide
Use: • averages
• decimals
• fractions
• percentages
• ratios
• reciprocals
• recognise standard notation (notation is putting symbols for numbers e.g. x = 2, y = 5, atomic mass, Z = 12)
• use standard notation
• understand signifi cant fi gures and use them appropriately
• use direct proportion (stepwise increases)
• use inverse proportion (inverse means turned up side down)
the inverse of 4 is ¼ (= 0.25)
• use numbers to the ‘power of 10’ e.g. 1 × 102 = 100
Your calculator will often show number to the power of 10 when you do calculations. Do not worry too much though – your calculator does the work for you.
Section 6: Appendices
104 Cambridge IGCSE Biology 0610
You should be able: Checklist Comments
• draw charts You will be given the data
• graphs with line of best fi t
interpret: • bar graphs
• pie charts
• line graphs
• fi nd the gradient and intercept of a graph
• select suitable scales and axes for graphs
• make approximations
recall and use the formulas: • area of a rectangle = length × width
• volume of a rectangular block = length × width × height
• area of a circle = π × radius2
• area of a triangle = base × height / 2
• volume of a cylinder = π × radius2 × height
• use and convert metric units into one another
e.g. 100cm = 1 m 1000g = 1 kg
• use mathematical and measuring instruments e.g. ruler, compasses, protractor
understand the meaning of:• angle
• curve
• circle
• radius
• diameter
• square
• circumference
• rectangle
• parallelogram
• diagonal
Section 6: Appendices
105 Cambridge IGCSE Biology 0610
You should be able: Checklist Comments
• solve equations of the form x = y + z and x = yz for any one term when the other two are known
Other important informationThe terms used in biology examination papers are given in the sections that follow. It is very important that you know and understand all of them before you take your examination. You should ask your teacher to explain anything that you are unsure about.
Numbers The decimal point will be placed on the line, e.g. 52.35.
Numbers from 1000 to 9999 will be printed without commas or spaces.
Numbers greater than or equal to 10 000 will be printed without commas. A space will be left between each group of three whole numbers, e.g. 4 256 789.
Units The International System of units will be used (SI units). Units will be indicated in the singular not in the plural, e.g. 28 kg.
(a) SI units commonly used in biology are listed below.
N.B. Care should be taken in the use of mass and weight. In most biological contexts, the term mass is correct, e.g. dry mass, biomass.
Quantity Name of unit Symbol for unit
length kilometre metre centimetre millimetre micrometer
km m cm mm µm
mass tonne (1000 kg) kilogram gram milligram microgram
(no symbol) kg g mg µg
time year day hour minute second y d h min s
amount of substance mole mol
Section 6: Appendices
106 Cambridge IGCSE Biology 0610
(b) Derived SI units are listed below.
energy kilojoule joule (calorie is obsolete) kJ J
(c) Recommended units for area, volume and density are listed below.
area hectare 104 m2 ha square metre m2
square decimetre dm2
square centimetre cm2
square millimetre mm2
volume cubic kilometre km3
cubic metre m3
cubic decimetre (preferred to dm3 litre) litre dm3 (not l) cubic centimetre cm3 (not ml) cubic millimetre mm3
density kilogram per cubic metre or kg m–3
gram per cubic centimetre or g cm–3
(d) Use of Solidus
The solidus (/) must not be used for a quotient, e.g. m / s for metres per second.
Presentation of data The solidus (/) is to be used for separating the quantity and the unit in tables, graphs and charts, e.g. time/s for time in seconds.
(a) Tables
(i) Each column of a table will be headed with the physical quantity and the appropriate unit, e.g. time / s.
There are three acceptable methods of stating units:
○ metres per sec
○ m per s
○ m s–1
(ii) The column headings of the table can be directly rewritten on to the axes of a constructed graph.
(b) Graphs
(i) The independent variable should be plotted on the x-axis (horizontal axis) and the dependent variable plotted on the y-axis (vertical axis).
(ii) Each axis will be labelled with the physical quantity and the appropriate unit, e.g. time/s. (iii) The scales for the axes should allow more than half of the graph grid to be used in both
directions, and be based on sensible ratios, e.g. 2 cm on the graph grid representing 1, 2 or 5 units of the variable.
(iv) The graph is the whole diagrammatic presentation. It may have one or several curves plotted on it. (v) Curves and lines joining points on the graph should be referred to as ‘curves’.
Section 6: Appendices
107 Cambridge IGCSE Biology 0610
(vi) Points on the curve should be clearly marked as crosses (x) or encircled dots (�). If a further curve is included, vertical crosses (+) may be used to mark the points.
(vii) Large ‘dots’ are penalised. Each data point should be plotted to an accuracy of better than one half of each of the smallest squares on the grid.
(viii) A best-fi t line (trend line) should be a single, thin, smooth straight line or curve. The line does not need to coincide exactly with any of the points; where there is scatter evident in the data, examiners would expect a roughly even distribution of points either side of the line over its entire length. Points that clearly don’t fi t should be ignored when drawing the best-fi t line.
(c) Numerical results(i) The independent variable should be plotted on the x-axis (horizontal axis) and the dependent
variable plotted on the y-axis (vertical axis). (ii) Each axis will be labelled with the physical quantity and the appropriate unit, e.g. time/s.
(d) Pie Charts
Use pie charts with the sectors in rank order, largest fi rst, beginning at 12:00 and proceeding clockwise, with no more than six sectors.
(e) Bar Charts
Use bar charts when one of the variables are categories, e.g. percentage of vitamin C in different fruits. They should be made up of narrow bars of equal width with a gap (not touching) between each bar.
(f) Histograms
Use histograms to plot frequency graphs with continuous data, e.g., frequency of occurrence of leaves of different lengths. The blocks should be drawn in order of increasing or decreasing magnitude and they should be touching.
Section 6: Appendices
108 Cambridge IGCSE Biology 0610
Taxonomy Taxonomy is the study of how organisms are arranged into groups. There are seven levels of taxon – kingdom, phylum, class, order, family, genus and species. These are the rule you need to know:
(a) The Five Kingdoms are:
○ Prokaryotes (Prokaryotae), including bacteria and blue-green bacteria ○ Protoctists (Protoctista), including green, red and brown algae and protozoans ○ Fungi (Fungi) ○ Plants (Plantae) ○ Animals (Animalia)
The viruses cannot be fi tted into this classifi catory system.
(b) The binomial system of naming gives each organism a two-word name. The fi rst word is the generic name and the second word is the trivial name, e.g. Homo sapiens. The trivial name should never be used without the generic name as well.
(c) Generic and trivial names are distinguished from the rest of the text either by underlining (when written or typed) or by being set in italics (in print).
(d) The generic name always takes an initial capital letter. The trivial name can be left off if it is clear which organsism it is. e.g. Plasmodium, and in these circumstances can stand alone.
(e) The common name should not normally be written with an initial capital letter, e.g. cat and dog. The exception is Man, where it is the common name for a species where the two sexes are distinguished by the terms man and woman.
(f) A species is not easy to defi ne but an acceptable general defi nition is as follows.
‘A group of organisms capable of interbreeding and producing fertile offspring.’
Genetics (a) The terms gene and allele do not mean the same thing.
A gene is a specifi c length of DNA occupying a position called a locus. A specifi c function can be assigned to each gene. An allele is one of two or more different forms of a gene.
(b) Use this standard form of presenting genetic crosses:
○ Use P for the cross of pure-breeding (homozygous) individuals ○ Use F1 for the offspring of homozygous parents ○ Use F2 for the offspring produced by crossing F1 parents.
(c) The format for the course of a genetic cross should be labelled in the following order:
○ Parental phenotypes ○ Parental genotypes ○ Gametes ○ Offspring genotypes ○ offspring phenotypes
(d) Chose a letter for the gene so that upper and lower case versions are ease to see the difference e.g. B and b. The upper case letter indicates the dominant allele and the lower case letter indicates the recessive allele.
Section 6: Appendices
109 Cambridge IGCSE Biology 0610
(e) The symbols for gametes should be circled to indicate the discrete nature of each gamete.
(f) Use a checkerboard to show genotypes that can result from random fusion of gametes.
(g) Use the word ‘codominance’ if the alleles are equally dominant, e.g. the AB blood group in humans.
Terminology Use English terms rather than Latin or Greek terms, e.g. red blood cell (not erythrocyte) unless there is none e.g. atrium, brinchi, villi.
Cambridge International Examinations1 Hills Road, Cambridge, CB1 2EU, United KingdomTel: +44 (0)1223 553554 Fax: +44 (0)1223 553558Email: [email protected] www.cie.org.uk
® IGCSE is the registered trademark of Cambridge International Examinations.
© Cambridge International Examinations 2015
Version 2
Top Related