Biology / Form 4 / Page 1 of 10

NINU CREMONA BOYS’ JUNIOR LYCEUM HALF-YEARLY EXAMINATIONS 2008/09

FORM 4 JL BIOLOGY TIME: 1Hr 30mins Name: ______________________________________ Class: ____________________

SECTION A: ANSWER ALL QUESTIONS IN THIS SECTION. This section carries 55 marks.

1. Fill in the blanks with the following words. These words can be used more than once or may

not be used at all.

Herbivores, incisors, grip, pointed, dentine, canines, carnassials, bones, incisors, pad, canines, carnassials, diastema, store, joint, sideways, mouth Different animals have different adaptations depending on their type of nutrition. Carnivores and ______________ have different types of teeth. Carnivores have ____________ at the front which are use to __________ and cut small pieces of meat. Next to them they have long, ___________ teeth called ______________ which are used to tear flesh. The following teeth are enlarged and they are called ______________. Their function is to scrape meat off the bones. Finally they have molars or cheek teeth which lock together to crush _____________. Herbivores have different kinds of teeth. They also have incisors at the front which are used to cut grass. Some of the large herbivores do not have _____________ on the top jaw. Instead they have a hard __________ against which the bottom incisors press to grip and pull grass. Herbivores have no ____________ and ______________. Instead they have a gap in their dentition which is called the _____________. This serves as a temporary ___________ of food. Herbivores also have cheek teeth which they use to chew and crush down grass. Herbivores have a loose jaw ____________ which allows them to move their lower jaw sideways.

(7 marks)

Biology / Form 4 / Page 2 of 10

2. Fill in and complete the following table:

Place where

enzyme is formed

Place where enzyme

acts

Name of enzyme

Function of enzyme

Salivary amylase

Breaks down starch into maltose

Gastric pits

in the stomach

Stomach

Pepsin

Duodenum

Trypsin

Epithelium

in the ileum

Ileum

Breaks down maltose to glucose

Pancreas

Pancreatic amylase

Pancreas

Duodenum

Breaks down fats

into fatty acids and glycerol

Sucrase

(6 marks) 3. A deficiency disease is an illness caused when a vitamin or a mineral is missing in the diet. Each

of the following persons is suffering from one such disease. They describe the symptoms of their disease as follows:

Sarah “Somehow, I always feel tired and breathless, while my skin looks very pale.” Mark “My gums bleed very easily, especially when I wash my teeth.” Matthew “I have to switch on the light in my room to see properly, even when it is not dark outside.” Jane “The doctor says that my bones are very brittle and my blood takes a long time to clot.”

Biology / Form 4 / Page 3 of 10

Name of person

Deficiency disease

Missing Vitamin or Mineral

Sarah

Mark

Matthew

Jane

(8 marks)

4. Robin Hoverfly Ladybird Caterpillar Greenfly X

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From the above food web name: (a) two carnivores ________________________________________________________________________

(2 marks) (b) two herbivores ________________________________________________________________________

(2 marks) (c) two predators ________________________________________________________________________

(2 marks) (d) one primary consumer ________________________________________________________________________

(1 mark) (e) one organism that might increase if caterpillars were removed ________________________________________________________________________

(1 mark) (f) Write the shortest food chain in this food web. ________________________________________________________________________

(1 marks) (g) Which one of the following is easier to destroy, a food chain or a food web? Explain your answer. ________________________________________________________________________ ________________________________________________________________________ ________________________________________________________________________

(3 marks) (g) What type of organism is organism X? ________________________________________________________________________

(1 mark)

Biology / Form 4 / Page 5 of 10

5. A pupil was given five food samples: A, B, C, D, E. Each food sample was tested for the

presence of Glucose (using Benedict’s solution), Starch (using Iodine solution), and Proteins (using sodium hydroxide and copper sulphate solutions).

The following table of results shows the final colour observed at the end of each test.

Food sample A

Food sample B

Food sample C

Food sample D

Food sample E

Benedict’s

solution

Orange

Blue

Blue

Orange

Blue

Iodine solution

Black

Black

Yellow/ brown

Black

Yellow/ brown

Sodium

hydroxide and Copper

sulphate solution

Blue

Blue

Purple

Purple

Blue

Which food sample contained: (a) protein only __________________________________________________________ (b) starch only ___________________________________________________________ (c) starch and glucose only _________________________________________________ (d) glucose, starch and protein _______________________________________________ (e) none of the substances __________________________________________________

(5 marks)

Biology / Form 4 / Page 6 of 10

6. The table below shows some of the gases contained in the air we breathe in and out. The figures are given in percentages.

% of gas Name of gas

Breathed in Breathed out

Oxygen

20.0

Carbon dioxide

0.03

Nitrogen

78.0

(a) Use the figures given below to complete the table by putting these percentages in the

correct spaces.

78.0 16.0 4.0 (3 marks)

(b) Write down two other ways in which the air we breathe out is different from the air we

breathe in.

1. __________________________________________________________________

2. __________________________________________________________________ (2 marks)

7. Use the terms listed below to fill in the following table. Ingestion, Assimilation, Digestion, Egestion, Absorption.

Components of indigestible matter are got rid of through the anus

Food is taken into the gut through the mouth

The soluble products of digestion are taken into the cells

Soluble products of digestion are absorbed into

the bloodstream and transported round the body

Food is broken down into soluble substances

(5 marks)

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8. (a) Proteins are built up of several small units. What are these units called?

________________________________________________________________________ (1 marks)

(b) What are the bonds found between these units called? ________________________________________________________________________

(1 marks) (c) Name 3 chemical elements always found in carbohydrates, fats and proteins. ________________________________________________________________________

(3 marks) (d) Name a fourth chemical element found only in proteins. ________________________________________________________________________

(1 marks)

Biology / Form 4 / Page 8 of 10

SECTION B: ANSWER QUESTION 1 AND CHOOSE ANY OTHER 2 QUESTIONS IN THIS SECTION.

This section carries 45 marks. 1. Read the following passage. Use the information in the passage and your knowledge to answer

the questions which follow: Training of athletes involves more than exercising muscles to increase their size. Physiological

changes are also important to supply sufficient energy to the muscles during the athletic event. If insufficient oxygen is available, the first stage of the energy-releasing process produces lactic acid. This is a toxic substance which if allowed to accumulate in the muscle cells, will cause them to remain contracted and give rise to a painful cramp.

Athletes may have different energy demands. For example, a rugby player has short, sharp bursts of activity whilst a marathon runner has to provide energy at a lower rate but over a much longer period. Both must not exceed their lactic acid tolerance level. With regular training, athletes can raise their tolerance level which helps them to obtain maximum energy without fatigue or cramps. After the event, an adequate supply of oxygen is needed to break down the lactic acid.

During vigorous exercise, the output of blood from the heart of a typical untrained person could be 120 cm per heart beat and the heart beat rate about 160 beats per minute. However, after that a person has trained and does the same exercise, the figures can change to 200 cm per heart beat and 120 beats per minute respectively. The breathing rate of the trained person may increase from about 40 to 55 breaths per minute during intense training.

(a) Name the process that produces lactic acid in humans.

(1 mark) (b) Write in words the chemical equation which shows the process mentioned in (a).

(2 marks) (c) Calculate the difference in volume of blood pumped out from the heart per minute by a typical exercising person, before and after training. Show your working.

(3 marks) (d) List three changes that would occur in the human body after strenuous exercise.

(3 marks) (e) Briefly explain how the body benefits from each change during the exercise.

(4 marks) (f) State one other change in breathing not given in the passage which would improve the athlete’s performance.

(2 marks) (Total: 15 marks)

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2. A student was asked to find out whether differences in pH had any effect on the activity of an enzyme which splits protein. The enzyme used was one which is found in the gut of mammals.

Seven test tubes were set up each containing 2% solutions of the enzyme. The solutions covered a range of pH from 3 to 9. at the end of the experiment, the student calculated the rate at which a standard amount of protein had been digested in each tube.

During the work, the student accidentally knocked over one of the test tubes and so could not obtain a full set of results. The table below shows the six results that were recorded.

pH Rate of protein breakdown

(in arbitrary units)

3 100

4 No result obtained

5 81

6 60

7 5

8 0

9 0

(a) On the graph paper provided using a large scale plot “rate of protein breakdown” on the y-axis against “pH” on the x-axis. Join the points with straight lines.

(8 marks) (b) Use the graph to estimate the following: (i) the rate of action of the enzyme at pH 4.

(2 marks) (ii) The pH at which a rate of 70 would be likely to have been recorded.

(2 marks) (c) (i) In which conditions does the enzyme used in the experiment work best, acid, neutral or alkaline?

(1 mark) (ii) Name one human digestive enzyme which would behave like the one used in the experiment.

(1 mark) (iii) Where in the human gut would this enzyme be produced?

(1 mark)

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(Total: 15 marks)

3. (a) Distinguish between aerobic and anaerobic respiration. (2 marks)

(b) In a mammal, how are the waste products of aerobic respiration removed from the alveoli to the exterior?

(2 marks) (c) Describe an experiment which you would carry out to show that yeast cells release carbon dioxide.

(5 marks) (d) Describe the economic importance of yeast to humans.

(6 marks) (Total: 15 marks)

4. (a) Describe using diagrams, how our air is pumped from the atmosphere into the lungs of a mammal.

(5 marks)

(b) Draw and label a diagram which shows the structure of a mammalian alveolus and its surrounding blood vessels.

(4 marks) (c) Mention 3 diseases caused by tobacco smoking.

(3 marks) (d) Name 3 air pollutants and for each pollutant, name one source.

(3 marks) (Total: 15 marks)

5. (a) Draw a simple clear diagram of the human digestive system. Label the following parts: gullet (oesophagus), stomach, small intestine, and large intestine.

(6 marks)

(b) On the same diagram draw and mark the positions of the liver and the pancreas. (2 marks)

(c) Give: (i) two functions of hydrochloric acid in the stomach (ii) two main functions of the small intestine (iii) one main function of the large intestine.

(5 marks) (d) Where is bile (produced in the liver) stored? What is its main function?

(2 marks) (Total: 15 marks)