GRADE 11 NOVEMBER 2014 LIFE SCIENCES P1 - Best … 11 november 2014 life sciences p1 marks: 150...

NATIONAL SENIOR CERTIFICATE

GRADE 11

NOVEMBER 2014

LIFE SCIENCES P1

MARKS: 150 TIME: 2½ hours

This question paper consists of 17 pages.

*ILFSCE1*

2 LIFE SCIENCES P1 (NOVEMBER 2014)

Copyright reserved Please turn over

INSTRUCTIONS AND INFORMATION Read the following instructions carefully before answering the questions. 1. Answer ALL the questions. 2. Write ALL the answers in your ANSWER BOOK. 3. Number the answers correctly according to the numbering system used

in this question paper.

4. Present your answers according to the instructions of each question. 5. Do ALL drawings in pencil and label them in blue or black ink. 6. Draw diagrams or flow charts only when asked to do so. 7. The diagrams in this question paper are NOT necessarily drawn to scale. 8. Do NOT use graph paper. 9. You may use a non-programmable calculator, protractor and compass. 10. Write neatly and legibly. 11. Round off all calculations to two decimals after the comma.

(NOVEMBER 2014) LIFE SCIENCES P1 3


SECTION A QUESTION 1 1.1 Various options are provided as possible answers to the following

questions. Choose the correct answer and write only the letter (A–D) next to the question number (1.1.1–1.1.9) in the ANSWER BOOK, for example 1.1.11 D.

1.1.1 The equipment below is used to treat the failure of which of the

following organs?

A Heart B Kidney C Liver D Lungs 1.1.2 Which ONE of the following is NOT the direct cause of kidney

damage? A High blood pressure B Bilharzia parasite C Diabetes D High cholesterol



1.1.3 The cartoon below illustrates the possible human impact on our

environment. Study the cartoon and answer QUESTIONS 1.1.3–1.1.5.

Which ONE of the following basic requirements for human

survival is produced by the innovative design, as illustrated in the cartoon?

A Water B Antibodies C Oxygen D Optimum body temperature 1.1.4 The bio-chemical reaction that yields the by-product mentioned

in QUESTION 1.1.3 is … A cellular respiration. B protein synthesis. C transpiration. D photosynthesis.



1.1.5 Study the following statements: (i) A light source is provided day and night. (ii) A steady supply of water is provided. (iii) The light source is switched off at night. (iv) A steady supply of carbon dioxide is guaranteed. Which ONE of the following combinations is designed to make

sure that there is a continuous supply of the by-product mentioned in QUESTION 1.1.3, for human survival?

A (i), (ii), (iii) and (iv) B (i), (ii) and (iv) only C (i), (ii) and (iii) only D (i), (iii) and (iv) only 1.1.6 Where does the emulsification of fat occur? A In the liver. B In the colon. C In the gall bladder. D In the small intestine. 1.1.7 Which labelled structure secretes a hormone which causes an

increased production of glycogen?

A W B X C Y D Z



1.1.8 What structures increase the surface area in the lungs? A Alveoli B Bronchi C The villi D The pleural membranes 1.1.9 Which ONE of the following represents density dependent and

density independent factors? Density dependent

factors Density independent

factors A Disease and competition Flood and drought B Fire and flood Food supply and predation C Food supply and disease Competition and predation D Competition and fire Flood and drought (9 x 2) (18) 1.2 Give the correct biological term for each of the following descriptions.

Write only the term next to the question number (1.2.1–1.2.8) in the ANSWER BOOK.

1.2.1 The cartilaginous structure that contains vocal cords 1.2.2 The blood cells that transport oxygen 1.2.3 Gradual increase in the average temperature of Earth’s biosphere 1.2.4 The maximum number of individuals that can be accommodated

by the resources of a particular habitat 1.2.5 Movement of individuals, or the part responsible for reproduction,

into or out of a population area 1.2.6 A group of organisms of the same species living together in the

same habitat and capable of random interbreeding 1.2.7 The type of plastid that absorbs radiant energy during

photosynthesis 1.2.8 The acid that accumulates in the muscles of humans during

continuous strenuous physical activity (8 x 1) (8)



1.3 Indicate whether each of the statements in COLUMN Ι applies to A only,

B only, both A and B or none of the items in COLUMN ΙΙ. Write A only, B only, both A and B, or none next to the question number (1.3.1–1.3.9) in the ANSWERBOOK.

COLUMN I COLUMN II 1.3.1 Oxidation of glucose in a

living cell A Anabolism

B Catabolism

1.3.2 Light dependent phase of photosynthesis

A Grana

B Stroma

1.3.3 Anaerobic respiration in yeast cells

A Carbon dioxide

B Ethyl alcohol

1.3.4 Blockage of urine flow A Gall stones

B Renal stones

1.3.5 Heavy ecological footprint A TV stays on day and night

B Leaking tap never gets fixed

1.3.6 Resource partitioning A Reduce overlapping of ecological niches

B Increase in biodiversity

1.3.7 Changes in species composition over time in a habitat that was not previously inhabited by organisms

A Commensalism B Mutualism

1.3.8 Simple sampling A Indirect technique B Direct technique

1.3.9 The average number of children born in one generation per female of child bearing age

A Fertility

B Fecundity

(9 x 2) (18)



1.4 The diagram below illustrates internal gaseous exchange. Study the

diagram and answer the questions.

1.4.1 Which respiratory gas is represented by X and Y respectively? (2) 1.4.2 Which physiological process is responsible for the movement of

gases as indicated by the arrows? (1) 1.4.3 Name TWO different ways in which the gas referred as X is

transported in the blood. (2) 1.4.4 Which protein plays an important role in the transport of the gas

referred to as Y. (1) TOTAL SECTION A: 50



SECTION B QUESTION 2 2.1 The diagram below represents aerobic respiration in humans. Study the


2.1.1 Identify phases 1, 2 and 3. (3) 2.1.2 Name X and Y. (2) 2.1.3 State the origin of X and Y. (2) 2.1.4 Identify products 1, 2 and 3. (3)



2.2 The diagram below illustrates the mechanism of breathing. Study the


2.2.1 Which apparatus (A or B) represents inhalation? (1) 2.2.2 Describe the mechanism of inhalation in humans. (6) 2.2.3 What human structures are represented by the glass tube, bell jar

and rubber sheet respectively? (3) 2.2.4 One of the learners created a hole in the rubber sheet by pricking it

with a nail. What would be the result when this punctured rubber sheet is stretched down? Give a reason for your response. (2)



2.3 The graph below shows the results of a glucose tolerance test on a

healthy (Person A) and on a diabetic (Person B). After fasting for ten hours they each were given a drink of a glucose solution containing 50 g glucose. The amount of glucose in their blood was then measured every 30 minutes for the next three hours.

2.3.1 What was the greatest concentration of glucose in the diabetic’s

blood? (1) 2.3.2 Predict from the graph how long it would take for the glucose

concentration of: (a) The healthy person to return to the level when the

glucose solution was taken. (2) (b) The diabetic person to return to the level when the

glucose solution was taken in. (2) 2.3.3 What effect would injecting insulin into the diabetic person have

on the results of the test? (1) 2.3.4 Into which compound does insulin change the blood glucose? (1) 2.3.5 Explain briefly why insulin, which is a protein, is injected into a

diabetic person, rather than given orally. (2)



2.4 The accompanying diagram represents a structure associated with the

human digestive system. Study the diagram and answer the questions that follow.

2.4.1 Identify the above structure. (1) 2.4.2 In which organ is this structure found? (1) 2.4.3 What is the main function of the structure shown in the above

figure? (1) 2.4.4 Name TWO substances which are found in higher concentration

in C than in D. (2) 2.4.5 Label parts A and B. (2) 2.4.6 State any ONE structural feature of the above diagram that

enables it to perform its function effectively.

(2)



QUESTION 3 3.1 The table below represents a certain kind of ecological interaction

between two wild animals in a game reserve. Study the table of data and answer the questions.

YEARS HARE POPULATION LYNX POPULATION 1975 350 200 1980 450 210 1985 250 350 1990 400 150 1995 250 370 2000 500 100 2005 250 400 2010 400 200 3.1.1 Plot a line graph to show the ecological relationship between the

hare and lynx population. (7) 3.1.2 From the graph, identify the growth phase representing the lynx

population between1975 and 1980. (1) 3.1.3 Supply any TWO reasons for the shape of the graph mentioned

in QUESTION 3.1.2. (2) 3.1.4 Briefly explain the interaction between the hare and lynx

population. (4) 3.1.5 Calculate the percentage decrease of hare population

between1990–1995. Show ALL calculations.

(3) 3.2 A learner has conducted an experiment in his classroom by following

various steps. Study the procedure and the diagram below to answer the questions that follow.

(a) A variegated plant was left in the dark for 3–4 days. (b) A starch test was conducted by removing one of the leaves. (c) The plant was then left in the light for 4 hours. (d) A leaf was removed and a drawing of it was made to show the

distribution of green and white areas. (Diagram 1) (e) The leaf was then tested for the presence of starch. (f) After the addition of few drops of diluted iodine solution, a second

drawing of the leaf was made to show the distribution of blue-black and brown areas of the leaf. (Diagram 2)



3.2.1 State the aim of this experiment. (1) 3.2.2 Why was the plant left in the dark for 3–4 days? (1) 3.2.3 Why should the plant have been tested for the presence of starch

after step (a), that is before exposing the plant to light? (2) 3.2.4 Draw and label Diagram 2 that shows the result of the second

starch test as mentioned in step (f). (Diagram 1 should be used as a template.) (5)

3.2.5 Is it necessary to set up a control for this investigation? (1) 3.2.6 Supply a reason for your answer in QUESTION 3.2.5. (2) 3.2.7 What conclusion can be drawn from this experiment? (2)



3.3 In many developing countries, the human population is increasing at an

exponential rate. An increase in human population leads to a proliferation of various industries and subsequent carbon emission. Study the passage below and answer the questions that follow:

Scientists of the University of Almeria are developing a new system to

eliminate carbon dioxide emissions using microalgae photosynthetic activity. The process is explained by the researchers: “By the gas emission point a water tank would be installed in order to retain the pollutant gases resulting from a specific industrial process. This polluted water would go through a system of bioreactors with microalgae culture system, which would then transform the CO2 emissions into vegetal matter and oxygen through the photosynthesis process.”

[Source:http://www.science20.com/news_releases/using_microalgae photosynthesis_to_eliminate_CO2_emissions]

3.3.1 According to researchers, which natural process can be utilised to

reduce carbon emission from industries? (1) 3.3.2 Identify the living organisms that can be employed to transform

polluted industrial gases into less hazardous air. (1) 3.3.3 Name TWO useful end-products generated during this process. (2)

http://www.science20.com/news_releases/using_microalgae%20photosynthesis_to_eliminate_CO2_emissions

http://www.science20.com/news_releases/using_microalgae%20photosynthesis_to_eliminate_CO2_emissions



3.4 The images below represent various types of malnutrition. Study the

images and answer the questions.

3.4.1 Identify the type of malnutrition illustrated by images A, B and C

respectively. (3) 3.4.2 What is the main cause of the conditions shown in images B and

C? (2) [40] TOTAL SECTION B: 80



SECTION C QUESTION 4 Write a short essay describing the homeostatic functioning of the nephron if a person consumes excessive amounts of water in a short period of time. (17)

Synthesis (3)

TOTAL SECTION C: 20 GRAND TOTAL: 150

NATIONAL SENIOR CERTIFICATE

GRADE 11

NOVEMBER 2014

LIFE SCIENCES P1 MEMORANDUM

MARKS: 150

This memorandum consists of 9 pages.



SECTION A QUESTION 1 1.1 1.1.1 B 33 1.1.2 D 33 1.1.3 C 33 1.1.4 D 33 1.1.5 B 33 1.1.6 D 33 1.1.7 D 33 1.1.8 A 33 1.1.9 A 33 (9 x 2) (18) 1.2 1.2.1 Larynx 9 1.2.2 Erythrocytes/red blood cells 9 1.2.3 Global warming 9 1.2.4 Carrying capacity 9 1.2.5 Dispersal 9 1.2.6 Population 9 1.2.7 Chloroplasts 9 1.2.8 Lactic acid 9 (8 x 1) (8) 1.3 1.3.1 B only 99 1.3.2 A only 99 1.3.3 Both A and B/Both 99 1.3.4 B only 99 1.3.5 Both A and B/Both 99 1.3.6 A only 99 1.3.7 None 99 1.3.8 A only 99 1.3.9 B only 99 (9 x 2) (18)



1.4 1.4.1 X = CO2 9 Y = O2 9 (2) 1.4.2 Diffusion 9 (1) 1.4.3 x In the form bicarbonate ions. 9

x In the form of carbaminohaemoglobin. 9 x In the blood plasma as dissolved gas. 9 (Any 2 x 1) (2)

1.4.4 Haemoglobin 9 (1) TOTAL SECTION A: 50



SECTION B QUESTION 2 2.1 2.1.1 Phase 1 – Glycolysis 3

Phase 2 – Kreb’s cycle 9 Phase 3 – Oxidative phosphorylation 9 (3)

2.1.2 X – Glucose 9

Y – Oxygen 9 (2) 2.1.3 X – Intake of food. 9 (end-product of carbohydrate digestion)

Y – Inhalation of oxygen 9 (2) 2.1.4 Product 1 – CO2 9

Product 2 – Highly energised hydrogen atoms 9 Product 3 – Water 9 (3)

2.2 2.2.1 B 3 (1) 2.2.2 x During the inhalation process, the diaphragm contracts 9 and

becomes less convex (flattens downward) increasing the volume of the thorax from top to bottom. 9

x The external intercostals muscles contract 9 and lift the ribs up and outward, increasing the volume of the thorax from front to back. 9

x This causes the thoracic cavity to be enlarged from side to side and from back to front. 9

x The total volume of the thoracic cavity increases 9 and pressure on the lungs (interpleural pressure) decreases. 9

x Since the atmospheric pressure is greater than the pressure on the lungs, 9 air rich in oxygen is drawn in through the air passages into the lungs. 9 (Any 6 x 1) (6)

2.2.3 Glass tube – Trachea 9

Bell jar – Thoracic cavity/thorax 9 Rubber sheet – Diaphragm 9 (3)

2.2.4 The balloon would not inflate. 9 This is because the hole in the

rubber sheet causes the pressure within the bell jar to become equal to the atmospheric pressure. 9 (2)



2.3 2.3.1 300 9 mg/100 cm3 (1) 2.3.2 (a) 2 hours 30 minutes/150 minutes 99 (2) (b) 3 hours 30 minutes/210 minutes 99 (2) 2.3.3 Regular injections of insulin would lower the blood glucose

concentration of the diabetic to normal. 9 OR it will also shorten the time it takes for the blood glucose concentration to return to normal after ingestion. 9 (1)

2.3.4 Glycogen 9 (1) 2.3.5 Insulin is a protein and therefore, digested in the human

digestive system. 9 It would therefore not be absorbed as insulin, but as its amino acids. 9 (2)

2.4 2.4.1 Structure of a villus 9 (1) 2.4.2 Small intestine 9 (1) 2.4.3 Absorption of digested nutrients 9 (1) 2.4.4 C – Large amounts of glucose 9 and amino acids 9 (2) 2.4.5 A – Columnar epithelium 9

B – Lacteal 9 (2) 2.4.6 x The thin columnar epithelium 9 of the villus enhance easy

absorption of nutrients across membrane by means of diffusion. 9

x The columnar epithelial cells have a brush border or microvilli 9 on the free surface to enlarge the surface area for absorption. 9

x The columnar epithelial cells produce carrier molecules, 9 which facilitate active absorption of nutrients against diffusion gradients. 9

x The goblet cells 9 between the columnar epithelial cells secrete watery mucus that prevents friction and keeps the cells moist. 9

x The villi contain many capillary blood vessels and lacteals in close contact 9with the absorption surface to take the absorbed food away fast and therefore, maintain steep concentration gradients for fast diffusion. 9 (Any 1 x 2) (2)

[40]



QUESTION 3 3.1 3.1.1

Checklist for the mark allocation of the graph Correct type of graph with points joined 1 Title of graph 1 Correct label for X-axis 1 Correct label for Y-axis 1 Appropriate scale for X-axis and Y-axis 1 Plotting points 1 mark: 4–8 points plotted

correctly 2 marks: 9–16 points plotted correctly

NOTE If the wrong type of graph is drawn:

x Marks will be lost for ‘correct type of graph’ If axes are transposed: x Marks will be lost for labelling of X-axis and Y-axis (7)

3.1.2 Lag phase/Establishment phase 9 (1)

0

100

200

300

400

500

600

1975 1980 1985 1990 1995 2000 2005 2010

POPU

LATI

ON

OF

HA

RE A

ND

LYN

X

TIME IN YEARS

GRAPH SHOWING PREY-PREDATOR INTERACTION BETWEEN HARE POPULATION AND LYNX

POPULATION DURING 1975 – 2010

HARE

LYNX



3.1.3 x Slow growth. 9

x Predators are still adapting to new environment/ acclimatisation. 9

x Finding partners is difficult. 9 x Organisms have not reached reproductive age/young

population. 9 (Any 2 x 1) (2) 3.1.4 x By feeding on the hare population, the lynx population reduce

the number of their prey. 9 x As the number of hare population(prey) drops 9 x more competition 9 among the lynx (predator) population

prevails. x Thus resulting in a decrease 9 in the number of predators x and an increase 9 in the number of hare population and a

corresponding increase 9 in the lynx (predator) population. x Finally the size prey-predator population stabilises 9 under

the carrying capacity 9 of the habitat resulting in a stable population. 9 (Any 4 x 1) (4)

3.1.5 ( ) 9

9 =

= 37,5% 9 (3) 3.2 3.2.1 To determine whether chlorophyll is necessary for

photosynthesis. 9 (1) 3.2.2 To destarch the plant. 9 (1) 3.2.3 To ensure that the leaves are completely destarched. 99 (2)



3.2.4

Marking guideline of the diagram: Criteria Marks Caption 1 Correct labels 2 Correct shading 2 (5) 3.2.5 No 9 (1) 3.2.6 Result obtained from the non-chlorophyllated area 9 of the leaf

can be compared with the result obtained from chlorophyllated area 9of the leaf. (2)

3.2.7 Chlorophyll is necessary 9 for photosynthesis. 9 (2) 3.3 3.3.1 Photosynthesis 9 (1) 3.3.2 Algae 9 (1) 3.3.3 Organic matter 9 and oxygen 9 (2) 3.4 3.4.1 A – Anorexia nervosa 9

B – Kwashiorkor 9 C – Obesity 9 (3)

3.4.2 B – Lack of protein in the diet 9

C – Excessive intake of energy-rich food 9 (2) [40] TOTAL SECTION B: 80



SECTION C QUESTION 4 x The effect of drinking a lot of liquid will be to make the blood and body fluids

more dilute than usual. 9 x When the water content of the body is above normal 9 x the osmotic potential of the blood decreases 9 x which signals osmoreceptors in the hypothalamus 9 that produces ADH 9 x to transmit impulses to the hypophysis to release less ADH in to the blood 9 x Therefore, less ADH reaches the kidney and causes a decrease 9 in the

permeability 9 of the walls of the x distal convoluted tubule and collecting duct 9 x less water is reabsorbed from the filtrate 9 x and a large amount of diluted urine is excreted 9 x The adrenal glands secrete less aldosterone 9 x which causes less sodium ions to be actively pumped out of the filtrate 9 x in the ascending limb of loop of Henle 9 x into the tissue fluid of the kidney medulla x This creates a high water potential or less negative osmotic potential 9 x Therefore, less water is reabsorbed 9 from the nephron tubule into the

tissue fluid of the medulla 9 x That means more water will be excreted as urine. Content (17) Synthesis (3) Assessing the presentation of the essay Criterion Relevance (R) Logical

sequence (L) Comprehensive (C)

Generally

All information provided is relevant to the topic.

Ideas are arranged logical/ cause – effect sequence

All aspects required by the essay have been sufficiently addressed

In this essay Only information

relevant to homeostasis (Osmoregulation) is given (There are no irrelevant information).

Generally various structures and their coordinated functioning towards achieving correct amount of water in the body are discussed.

Role of hypophysis, adrenal gland and the effect of their hormones on the target structure of the kidney are thoroughly discussed.

Marks 1 1 1

TOTAL SECTION C: 20 GRAND TOTAL: 150

GRADE 11 NOVEMBER 2014 LIFE SCIENCES P1 - Best … 11 november 2014 life sciences p1 marks: 150...

Documents

Transcript of GRADE 11 NOVEMBER 2014 LIFE SCIENCES P1 - Best … 11 november 2014 life sciences p1 marks: 150...