Bio P2 Sbp 2007

Name:………………………………………………… 4551/2 Biology Paper 2 October 2007 1 2 hours 2

Form :…………………………………………….

SEKTOR SEKOLAH BERASRAMA PENUH BAHAGIAN SEKOLAH KEMENTERIAN PELAJARAN MALAYSIA DIAGNOSTIC TEST FORM FOUR BIOLOGY PAPER 2 Two hours thirty minutes

DO NOT OPEN THE TEST PAPER UNTIL YOU ARE TOLD TO DO SO 1.

This paper consists of three sections. Section A, Section B and Section C. Answer all the questions in Section A, one question in Section B and one question in Section C. 2. Write your answers in the spaces provided for Section A. Important steps in calculations must be shown . 3. Write your answers on the separate answer sheets provided for Section B and Section C. 4. Answer Section B and Section C in detail. You may use equation, diagram, table, graph and other suitable methods to explain your answers. 5. Show your working, it may help you to get marks. 6. If you wish to change your answer, neatly cross out the answer that you have done. Then write down the new answer 7. The diagram in the questions are not drawn to scale unless stated. 8. Marks allocated for each question or part of the question are shown in brackets. 9. The time suggested to answer Section A is 90 minutes, Section B is 30 minutes and Section C is 30 minutes. 10. The use of a non programmable calculator is permitted.

Section

For Examiner’s Use Full Marks Question Marks Obtained 1 12 2

12

A 3 4 5 6 7 8 9

B C Total

12 12 12 20 20 20 20 100

This Question Paper Consists of 18 Printed Pages 4551/2 @ SBP 2007

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SECTION A [60 marks] Answer all questions from this section.

1. Diagram 1.1 shows an example of cell organization in a multicellular organism.

Diagram 1.1 (a) (i) Name the different types of cells shown in P, Q and R P: ……………………........................... Q: …………………………………….. R: …………………………………….. [2 marks] (ii) State the functions of these cells. P: ……………………………………………………………………………….. ………………………………………………………………………………. Q: ……………………………………………………………………….............. ………………………………………………………………………………..

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R: ……………………………………………………………………………….. ……………………………………………………………………………….. [3 marks] (b) Based on the information obtained from diagram 1.1, explain the meaning of cell specialization. ……………………………………………………………………………………... ……………………………………………………………………………………... ……………………………………………………………………………………... [1mark] (c) Name the organ in diagram 1.1 and the tissues that form it. ……………………………………………………………………………………… ……………………………………………………………………………………… [2 marks] (d ) The human skin and the epidermis of plants act as a barrier against water loss, mechanical injury and infection by microorganisms. However, the human skin can also perform other functions like temperature regulation, excretion and sensory perception. Explain the above statement. ……………………………………………………………………………………... ……………………………………………………………………………………... …………………………………………………………………………………….. …………………………………………………………………………………….. ……………………………………………………………………………………. ……………………………………………………………………………………. …………………………………………………………………………………… [4 marks]

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2. Diagram 2.1 shows a schematic diagram of the mechanism of photosynthesis.

Water Process Z OH-

H+

Hydrogen atom

Oxygen

eChlorophyll

eWater

Reaction X

Reaction Y Carbon dioxide

ATP

Water Glucose

DIAGRAM 2.1 (a)

Identify the parts of a chloroplast where the two reactions of photosynthesis take place. Reaction X: ………………………………………………………………………………… Reaction Y: …………………………………………………………………………………. [2 marks]

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Name one type of cell where reactions X and Y take place. ………………………………………………………………………………… [1 mark]

(c)

Compare reaction X and reaction Y in other aspects that do not involve light energy. ………………………………………………………………………………… ………………………………………………………………………………… ………………………………………………………………………………… [2 marks]

(d)

Explain process Z. ………………………………………………………………………………… ………………………………………………………………………………… …………………………………………………………………………………. ………………………………………………………………………………… [2 marks]

(e) (i)

The leaves of some temperate plants like pine trees are evergreen and do not fall in winter. Explain the effect of winter on the rate of photosynthesis. ………………………………………………………………………………… ………………………………………………………………………………… ………………………………………………………………………………… ………………………………………………………………………………… [3 marks]

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Explain how farmers can overcome the above problems in order to maintain the productivity of crops in winter. ………………………………………………………………………………… ………………………………………………………………………………… ………………………………………………………………………………… ………………………………………………………………………………… ………………………………………………………………………………… [2 marks]

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3. Diagram 3.1 shows a part of the respiratory system of humans.

Blood capillary

cell

DIAGRAM 3.1 (a)(i) Name structures X and Y Structure X : …………………………………………………………………… Structure Y : …………………………………………………………………… [2 marks] (ii) Name the process that enables the exchange of the respiratory gases to occur between X and Y. …………………………………………………………………………………….. [1 mark]

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(iii) Explain how the differences in the partial pressures can cause the exchange of the respiratory gases between X and Y and between X and the body cells. ……………………………………………………………………………………… ……………………………………………………………………………………… ……………………………………………………………………………………… ……………………………………………………………………………………… ……………………………………………………………………………………… ………………………………………………………………………………………. ……………………………………………………………………………………… [ 4 marks ] (b) If carbon monoxide gas from the car exhaust was accidentally inhaled , explain how exposure to the gas for several minutes can lead to death. ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… . [ 2 marks ] (c) During heavy physical activities the muscles of the hands and legs can become fatique and the individual will pant, feel tired and weak. Explain the changes that occur in the body during this period. ………………………………………………………………………………………….. ………………………………………………………………………………………… ………………………………………………………………………………………….. ………………………………………………………………………………………….. ………………………………………………………………………………………….. [ 3 marks ]

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4. Diagram 4.1 shows a stage during a type of cell division in an animal cell.

homologous chromosomes

DIAGRAM 4.1

a) (i) Name the stage of the cell division shown in diagram4.1 ………………………………………………………………………………… [ 1 mark ] (ii) How many chromosomes are there in the cell? …………………………………………………………………………………. [ 1 mark] (b) Based on what you have learnt about mitosis and meiosis, explain whether the cell in Diagram 4.1 is formed by a normal cell division. ……………………………………………………………………………………… ……………………………………………………………………………………… ……………………………………………………………………………………… ……………………………………………………………………………………… [ 2 marks ]

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(c) If the cell in Diagram 4.1 undergoes a meiotic division, draw a labelled diagram to show the behavior of the chromosomes during Metaphase 1.

[ 3 marks ] (d) Down’s Syndrome is the result of an additional chromosome, causing each somatic cell to have a total of 47 chromosomes instead of the normal 46 chromosomes. The affected individual have certain characteristics like slanted eyes, short stature and mental retardation. Based on the above information, explain what went wrong to the gametes that form a child with the above mentioned genetic disorder. ……………………………………………………………………………………… ……………………………………………………………………………………… ……………………………………………………………………………………… [ 2 marks ] (e) Explain how meiosis plays an important role in sexually reproducing organisms whilst mitosis plays an important role in the formation of clones. ……………………………………………………………………………………... ……………………………………………………………………………………... ……………………………………………………………………………………... ……………………………………………………………………………………... [ 3 marks ]

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5. Three different populations in a small lake are linked in a food chain. Diagram 5.1 shows the changes in size of these populations over a period of time.

Diagram 5.1

(a)(i) Using the information in Diagram 5.1 identify the producer .......................................................................................................................... (ii)Name the trophic level in the food chain of organisms A. ………………………………………………………………………….................... .[2 marks] (b) Referring to the graphs, suggest what substances may have entered the lake at time B. Explain your answer. .......................................................................................................................................... .......................................................................................................................................... …………………………………………………………………………………………. ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… [5 marks]

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(c) Explain how the change in the size of the population of bacteria after time C is related to the size of the plant population. ..................................................................................................................................... ……………………………………………………………………………………….... ……………………………………………………………………………………….. [2 marks] (d) Suggest a method to estimate the fish population in the lake throughout the period. ……………………………………………………………………………………… ……………………………………………………………………………………… [1mark] (e) Diagram 5.2 is a graph that shows the amount of oxygen in the same lake before time B. Complete the graph to show how the oxygen concentration will change over the same time period shown in Diagram 5.1. [2 marks]

Diagram 5.2

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SECTION B [20 marks] Answer any one questions from this section.

6

(a)

Diagram 6.1 shows the structure of an enzyme and two types of substrate in one part of the human digestive system.

DIAGRAM 6.1 Based on diagram 6.1, explain the mechanism of enzyme action . [ 4 marks ]

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Diagram 6.2 shows the digestive system of humans, ruminants and rodents .

DIAGRAM 6.2

Based on diagram 6.2, compare the digestive system of humans, ruminants and rodents and the digestion of cellulose. [ 10 marks] (c) A patient suffering from intestinal cancer has to undergo an operation to remove a part of his intestines. Explain the problems regarding nutrition that the patient would be facing after the operation. [ 6 marks]

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7. The graph in Diagram 7.1 shows the relationship between the populations of rats and owls in an oil palm plantation.

Population of animals

owls rats

Time (months) DIAGRAM 7.1

a Based on diagram 7.1, describe the relationship between the rats and the owls in the oil palm plantation ? . [ 6 marks ] b

Describe the interactions between the following organisms. - A clown fish and sea anemones - Alga and fungus ( lichen ) [ 4 marks]

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c. Diagram 7.2 shows the nitrogen cycle in a vegetable farm .

DIAGRAM 7.2 Describe what will happen to the rate of vegetable production if organisms P and Q die as a result of excessive use of pesticides in the vegetable farm. [ 10 marks]

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SECTION C [20 marks] Answer any one questions from this section. 8

(a)

Table 1 shows a daily energy requirement of various individuals. INDIVIDUAL

i ii iii iv v vi vii

DAILY ENERGY REQUIREMENT (kJ)

Very active man Breast feeding woman Average woman aged 25 Boy aged 12 – 15 Girl aged 12 – 15 Child aged 7 Man aged 70

15 100 10 000 9 200 11 700 9 600 7 500 8 500

TABLE 1 Explain the daily energy requirement for any three groups of individuals as compared to that of an average woman aged 25. [10 marks] (b)

Based on Table 2, suggest and justify an appropriate menu for each target group: (i) pregnant mothers (ii) people with cardiovascular disease (iii) teenagers aged 17 Food

Protein (g)

Lipid (g)

Carbohydrate (g)

Minerals

Vitamins

Calcium (mg)

Ferum (mg)

A (µg)

D (µg)

B1 (mg)

0 0 0 155.0 0 0 44.00 900.0 0 8.00 10.00

0 0 0 0.10

0.08 0.18 0.06 0.09

0 0.05 8.00

0.08 0.04 0

0 0.02

0.10 0.05

Rice Bread Beef Eggs

6.2 8.00 18.10 12.30

1.0 1.70 17.10 10.90

86.8 54.30 0 4.20

4.0 100.00 7.00 100.00

0.4 1.70 1.90 0.10

Fish Milk Margarine

17.40 3.30 0.20

0.70 3.80 81.50

0 4.80 0

16.00 120.00 4.00

0.50 0.10 0.30

Oranges Yoghurt

0.80 5.00

0 1.00

8.50 6.40

41.00 180.00

0.30 0.10

TABLE 2 [ 10 marks]

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Diagram 9 shows one source of air pollution.

DIAGRAM 9 a

Name three other types of air pollutants and describe their effects on living things. [ 10 marks]

b

Suggests strategies that can be taken to reduce air pollution. [ 10 mark]

END OF QUESTION PAPER

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MARKING SCHEME: BIOlOGY PAPER 2 Parts of question 1(a)(i)

(ii)

Criteria/Explanation P : red blood cell Q: heart muscle cell R: epithelial cell

Mark/ score

Remark

2 marks

3 correct- 2m 2 correct- 1m 1 correct- 0m

Sample answer: P: Transport oxygen from lungs/heart to all the cells 3 marks in the body in the form of oxyhaemoglobin/ Transport carbon dioxide from cells to lungs in the form of carbaminohaemoglobin Q: Form the muscular tissues of the wall of the heart that can contract and relax to pump blood to all parts of body. R: Form a continous protective layer over the surface of the heart ( pericardium) /other body surfaces

(b)

(c)

(d)

Sample answer: Process in which cells grow, change shape and differentiate in order to carry out specific functions. F1: Heart F2: The heart has muscle tissues, connective tissues and epithelial tissues ( also nerve tissue but not in diagram) Sample answer: F1: The human skin is an organ whereas the epidermis of a plant is a tissue E1: Both skin and epidermis consist of cells that are interconnected and continous E2: form a protective layer over the surface F2: Skin has other tissues : - connective tissues like blood for temperature regulation - nerve tissue for sensory perceptions and temperature control - epithelial tissue forms protective layer and sweat glands for excretion (urea) - muscle tissue like erector pili muscle for temperature control.

1mark

2 marks

1 mark 1 mark

Any 2 correct 2 marks

Total=12

Parts of Question 2(a)

Criteria / Explanation

Mark / Score

Remark

Able to identify the parts of chloroplast where reaction X (light reaction) and reaction Y (dark reaction) take place. Answer : Reaction X : grana Reaction Y : stroma

(b)

1 1

Accept also thylakoid

Able to name one type of cell where reaction X takes place. Answer : Palisade mesophyll cell / spongy mesophyll cell / guard cell

(c)

1

Able to contrast between reaction X (light reaction) and reaction Y (dark reaction). Sample Answer :

F2

F3

Reaction X (light reaction)

Reaction Y (dark reaction)

Require water for photolysis

Require hydrogen for reduction of carbon dioxide Produce glucose as the final product

Produce ATP and oxygen

1 1

2

Parts of Question (d)

Criteria / Explanation

Mark / Score

Remark

Able to explain process Z based on the criteria below : F : name of process Z E : products of process Z Sample Answer : F : photolysis of water E : Light energy is used to split water molecules into hydroxyl ions (OH-) and hydrogen ions (H+)

1 1

(e) (i) Able to explain the effect of winter on the rate of photosynthesis. Sample Answer :

(e) (ii)

F : Rate of photosynthesis decreases E1 : Low light intensity E2 : Low temperature

1 1 1

Able to identify and explain ways to maintain the productivity of crops in winter. Sample Answer : F : Grow the crops in greenhouse. E : Temperature and light intensity are artificially controlled.

1 1

Total=12

Parts of Quest.

Criteria/Explanation

Mark/Score Remark

3a(i)

Structure X: red blood cell Structure Y: alveolus

1 1

a(ii)

Simple diffusion

1

a(iii)

Sample answer: At alveolus : F1- partial pressure of oxygen is higher in Y(alveolus) than in X(red blood cell) E1- oxygen diffuses from Y to X following the concentration gradient. F2E2-

partial pressure of carbon dioxide is higher in X /blood than in Y Carbon dioxide diffuses from X to Y following the concentration gradient

At body cells : F3- partial pressure of oxygen is higher in X than in body cells E3- oxygen diffuses from X into body cells. F4- partial pressure of carbon dioxide is higher in body cells than in X E4- carbon dioxide diffuses from body cells to X

(b)

1

1 mark for each pair of fact and explanation correct.

1

1

1 4marks

Sample answer:

F1- carbon monoxide combines faster with haemoglobin than oxygen E1- form carboxyhaemoglobin (permanently) / carboxyhaemoglobin does not breakdown to release haemoglobin E2- haemoglobin cannot transport oxygen to cells E3- cells lack oxygen for respiration and die.

1

F1 correct

1

Any explanation (E1/E2/E3)

2 marks

(c)

Sample answer:

F1: oxygen debt occurred/ anaerobic respiration occurred E1: blood cannot supply enough oxygen to muscle cells E2: muscle cells undergo anaerobic respiration to obtain extra energy E3: glucose breakdown partially into lactic acid E4: accumulation of lactic acid causes muscle fatique E5: panting occurs to inhale more oxygen to oxidize lactic acid to carbon dioxide and water.

1

1

1 fact and any 2 explanations 1

3 marks

Total=12

Criteria/ Explanation Parts of Question 4(a) (i) Able to name the stage of the cell Sample Answer:  Prophase (of mitosis)  (Early) Prophase I (of Meiosis) (ii) Able to count the number of chromosomes: - 7 chromosomes

(b)

Able to give a definite answer Answer: No

Mark/score

1

1

1

Able to explain  fact  explanation Sample Answer:  F1 : This is not a normal diploid cell  P1: because there is an extra chromosome that cannot form a 1 homologous pair (c)

Able to draw the Metaphase I accurately:  3 pairs of homologous chromosomes at the equatorial plate  1 chromosome without its homologous pair  Spindle fibers formed Able to label chromosome and spindle fiber Sample answer

2

1

1 1

3

1

1F and 1E

Refer diagram 4c (d)

F:Abnormal meiotic division E1: form abnormal gametes with extra chromosomes E2 : fusion of normal sperm with 23 chromosomes with abnormal ovum with 24 chromosomes E3 : Zygote formed has 47 chromosomes

1

Remark

(e)

Able to state the importance of meiosis: Sample Answer: F: Maintain the chromosomal number of an organism from generation to generation E:Produce gametes (with haploid number of chromosomes.) Able to state the importance of mitosis: Sample answer:

1

1

1

3

E: Produce genetically identical organisms with the same characteristics. 12marks TOTAL

Diagram 4 c Metaphase 11 ( abnormal cell division)

Parts of Question 5(a)(i)

Criteria/explanation Algae/ phytoplanktons/ aquatic plants

Mark/ Score 1 mark

(ii)

Trophic level 2 (primary consumer)

1 mark

Remark

Sample answer (b) F1: Inorganic fertilizers/ domestic sewage entered lake. E1: Nutrients encourage algae to grow rapidly ( algal bloom) E2: High density of algae cause light intensity in water to be greatly reduced E3: Death of plants/algae/submerged plants/ eutrophication E4:: decomposition by bacteria E5: Population of bacteria increases E6: dissolved oxygen concentration decreases ( BOD increases) E7: Death of aquatic organisms eg. population of fish decreases (c )

(d)

1 mark

Any 4 correct explanation

5marks

Sample answer: F: Population of plants decreases but population of bacteria increases.

1mark

E: After time C death of plants leads to decomposition of these organisms by bacteria./dead plant matter become food for the bacteria ( decomposers)=

1mark

The capture , mark , release and recapture technique

1mark

(e) Concentration of oxygen increased slighty but after time C the concentration of oxygen decreases sharply to a very low value.

2 marks

MARK SCHEME - ESSAY No

Sec.

6

a

1

Accepted points / description / explanation

M1

M Sum

Able to explain the mechanism of enzyme action Sample answers 1. 2. 3. 4.

Enzyme has an active site that complement to the protein. Protein binds to the active site to form enzyme-protein substrate. The enzyme catalyses the protein to form products/ polypeptide. Products leave the active site of enzyme molecules.

1 1 1 1 4

b

Able to state the differences in the digestive process of humans, ruminants and rodents Humans Omnivores

Ruminants Herbivores

Single stomach chamber Caecum are about the same size as other parts of colon Bacteria present throughout the large intestine

Stomach with four chambers Caecum are about the same size as other parts of colon Bacteria and protozoa present in the stomach

Unable to digest cellulose

Able to digest cellulose

Rodents Mostly are herbivores, some are omnivores Single stomach chamber Big and well developed caecum

2

2

2 Bacteria and protozoa present in the caecum

2

Able to digest cellulose

2

* 3 corrects = 2 marks 2 corrects = 1 mark 1 correct = 0

10

MARK SCHEME - ESSAY

6c

2

Able to explain the problems regarding the nutrion after the operation. Sample answer

F1: Less production of the enzyme erepsin/ peptidase/maltase/sukrase/lactase/ lipase. E1: The rate of food digestion is slow

1

F2: Slow absorption of glucose/ galactose/ fructose / amino acid/ glycerol and fatty acid/ vitamin/ mineral E2: Less digested food absorbed

1

F3: The patient become exhausted E3: Less absorption of glucose in the blood// rate of respiration is low.

1 1

F4: Late recovery / healing of wound E4:Slow cell replacement because of slow absorption of amino acid.

1 1

1

1

6 Max:6 TOTAL

20

MARK SCHEME - ESSAY No

Sec.

7

a

Accepted points / description / explanation

3 M1

M Sum

Able to describe the relationship between the rats and the owls P1: The relationship between rats and owls are prey-predator P2: The owl is the predator of rats P3: The rat is the prey of owls. P4: An increase in the rat population is followed by an increase in the owl popuation. P5: Conversely when the rat population decreases the owl population decreases. P6: The prey and the predator regulate each other’s population and this maintains the population of both organisms in a dynamic equilibrium.

1 1 1 1 1 1 6

Able to describe the interactions between i.

b.

Clown fish and sea anemones

P1: P2: P3:

Type of interaction is commensalism The clown fish lives among the tentacles of sea anemones The clown fish is protected from its predators and it also feeds on the remnants of the anemones’ food. P4: On the hand , the sea anemones, do not benefit from this relationship.

1 1 1 1 Max: 2

ii. P1: P2:

Alga and fungus ( lichen)

Type of interaction is mutualism Relationship between two species of organisms in which both benefit. P3: The alga produces food for itself and also for the fungus. P4: The fungus supplies carbon dioxide and nitrogen for alga to produce food.

1 1 1 1 Max: 2

4

MARK SCHEME - ESSAY No

Sec.

7

c

4

Accepted points / description / explanation

M1

M Sum

Able to describe the rate of production of vegetables if organsims P and Q die because of excessive use of pesticides in vegetable farms. Sample answers: P1: Organism P ( decomposer) will die P2: Breakdown of protein in dead organisms will not occur. P3: Less nitrogen compounds in the soil. P4: Less production of protein from the producers P5: Organism Q ( Nitrogen fixing bacteria) will die P6: Nitrogen from the atmosphere will not undergo the process of nitrogen fixing. P7: No production of ammonium, nitrate and nitrite ions in the soil. P8; No absorption of minerals such as ammonium, nitrate and nitrites to the plants. P9 Less production of protein from the producers P10: Lack of protein sources in plants/ vegetables.

1 1 1 1 1 1 1 1 1 1

10 TOTAL

20

MARK SCHEME - ESSAY No

Sec.

8

a

5

Accepted points / description / explanation

M1

M Sum

Able to explain the factors tha affecting the daily energy requirement of human body based on the criteria below: F: Statement of the daily energy requirement of human body based on the criteria below: F: Statement of the daily energy requirement of the group in relative to that of an average woman. E: Explanations. Sample Answer: F1: Man aged 70 years old requires lower daily energy requirement E1: Age factor/ the man is older than the average woman. E2: The old man is less active than the average woman. Any three groups

1 1 1 3X3= 9

KS: Able to give three sets of statement with any one corresponding explanation. Example: F1 +F2+ F3 and any corresponding E

1

10

MARK SCHEME - ESSAY No

Sec.

8

b

6

Accepted points / description / explanation

M1

Able to justify the selection of an appropriate menu for target group based on the criteria below : For each target group : F1 statement of menu E1 justifications F2 E2

statement of menu justifications Max 3

Sample Answer : (i) Pregnant mothers should take : F1 : Beef / eggs / fish. E1 : High protein diet for growth of foetus.

1 1

F2 : Yoghurt / milk / eggs. E2 : Calcium / vitamin D rich for bone development of foetus.

1 1

F3 : Beef / bread. E3 : For manufacture of haemoglobin.

1 1

Any 2F with one corresponding E Max 3 3 (ii) People with cardiovascular disease should take : F1 : Fish / yogurt / oranges. E1 : Low cholesterol food.

1 1

F2 : Use less oil in cooking / steam food/ boil / grill. E2 : Lipid can be converted to cholesterol // excessive cholesterol can deposit in the artery wall.

1 1

Any 2F with one corresponding E 3 Max 3

M Sum

MARK SCHEME - ESSAY

7

(iii) Teenagers should take F1: bread/ rice E1: high carbohydrate to supply energy for active lifestyle.

1 1

F2: beef/ fish E2: high protein for growth

1 1

F3: Yoghurt / milk E3: high ccalcium for growth and development of bones.

1 1

F4: Margarine E4: high vitamin D for growth and development of bones .

1 1

Any 2F with one corresponding E Max: 3 3 KN= For a complete combination of F and E from each group Example: Group (i) : F1+ E1// F2 + E2 Group(ii) : F1+ E1// F2+ E2 Group(iii) : F1+ E1// F2+ E2

1 10

TOTAL

20

MARK SCHEME - ESSAY No

Sec.

9

a

8

Accepted points / description / explanation

Able to name any three types of pollutant : Sulphur dioxide Nitrogen oxides Carbon dioxide Lead

M1

M Sum

1 1 1 1 Max: 3

Able to describe the effects of pollutants on living things

Pollutants

Effect on living things

Sulphur dioxide

- Irritates and damages the lining of the eyes, air passages and lungs. - Combines with rainwater to form acid rain that may cause skin diseases

1

- Damages tissues of the lungs and cause bronchitis - Irritate the eyes -Lower the body’s defence against flu

1

- Combines with haemoglobin to form carboxyhaemoglobin which reduces the capacity of the blood to transport oxygen . - Causes dizziness and headache - Slows down the brain.

1

- Reduces the sensitivity of the hands and feet coordination - Coma or death - Disrupts the ability of the body to produce new cells. - Cause retardation of brain in children.

1

Nitrogen oxides

Carbon monoxide

Lead

1

1 1

1 1

1 1 1 Max: 7

10

MARK SCHEME - ESSAY

b.

9

P1: Encourage sharing of vechicles to reduce congestion on the roads. P2: Provide sufficient and alternative types on transport services which are more effective . P3: Campaign programmes should be carried out to attract the usage of public transport by the public. P4: Enforce the usage of petrol without lead. P5: Make it compulsory to use pollutant filters for the exhaust pipes of vechicles and factory chimneys. P6: Strict measures should be taken against open burning by punishing offenders with heavy fines. P7: Implemetation of laws to punish offenders P8: use of technology examples; use of catalytic converters, unleaded petrol, air filters for chimneys. P9: Education: example: reduce, reuse and recycle resources P10: renewable energy, example: solar energy, wind energy , geothermal P11; efficient use of energy.

1 1 1 1 1 1 1 1 1 1 1 Max: 10

TOTAL

10

20