ans p2 johor 2010

SULIT 4551/2

Marking schemeSection A

Question 1

Question Mark Scheme Mark1(a) Able to state the types of solutions

Sample answersSolution J: Hypotonic solutionSolution K: Isotonic solutionSolution L: Hypertonic solution 1+1+1 3

(b) Able to explain the difference in curvature

Sample answerSolution J:F1: The strip in solution J curved outwards/ towards the

epidermis/ epidermal layerP1: (Cortex) cells/ (parenchyma) cells become turgid/ longer

because water diffuses into the cell/ protoplasm/ cytoplasm by osmosis.

P2: Epidermal cells have a layer of cuticle on the outside P3: which resist/ restrict the entry of water (and retain its normal

size)Any 2

Solution L:F2: The strip in solution L curved inward/ towards the cortex/

parenchyma layerP4: Water diffuses out of the cytoplasm/ protoplasm of the

(cortex) cells/ (parenchyma) cells by osmosisP5: The cytoplasm and/or the vacuole of the cells will shrink

Any 2

1+1

1+1 4(c)(i)

(c)(ii)

Able to state the solution isotonic to the cell sap

Sample answerSolution K

Able to give reasons correctly

Sample answerP1: The strip in solution K remain straight P2: because the (cortex/ parenchyma) cells have not increase

turgidity/flaccidity// no change in size/ remain the same sizeP3: Water diffuses in and out of the cells by osmosis at the

same rate// Rate of endosmosis equal rate of exosmosis Any 2

1

1+1 3

4551/2 © 2010 Hak Cipta JPNJ SULIT

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SULIT 4551/2

(d) Able to draw the labelled diagram

D: Correct drawing with vacuole doubled-line cell wall plasma membrane pulled away with some parts attached to

the cell wall (totally detached from the cell wall is not accept)L: Correct labels plasma/ cell membrane vacuole

1

1

2

Total 12

Question 2

No Mark Scheme Mark2 (a)(i) Able to state the type of cell division involved in cell cycle in

Diagram 2

Answer :Mitosis/Mitotic cell division 1

3

(a)(ii) Able to state one reason for answer in (a)(i)

Sample answer :P1 : Produces 2 daughter cellsP2 : Occurs at root tip

Any 1 P1

(a)(iii) Able to arrange the phases in Diagram 2 in correct sequence by using the letters in Diagram 2

Answer : Q R T S P

1(b) Able to explain why root tip is used for preparing slides to

show this cell cycle

Sample answer :F : Root tip is growing regionP : the cells are actively divide

1+12


Plasma/ Cellmembrane

Vacuole

Cell wall

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(c)(i) Able to name stage Q

Answer :Interphase 1

3

(c)(ii) Able to explain the importance of stage Q to this cell cycle

Sample answer :F1: Replication of DNA occursP1: to produce two genetically identical daughter cellsF2 : Synthesis ATP//accumulate energyP2 : Enable the cell to divide

Any 2 1+1

(d)(i) Able to define cloning

Sample answer :P1: Process of producing genetically identical organismsP2: through asexual reproductionP3: by stem/leaf cutting/layering/grafting/any suitable example

Any 2

1+1

4

(d)(ii) Able to state one advantage and one disadvantage of cloning

Sample answer :

Advantage :P1: Large numbers of offspring can be produced P2: in a short time P3: The good characteristic of parent can be maintained in the

offspringAny 1 P

Disadvantages :P3: The offspring produced do not show any genetic variationP4: The offspring produced have same level of resistance to

certain diseases/pestsAny 1 P

1

1

TOTAL 12

Question 3

No Mark Scheme Mark3 (a)(i) Able to state the process by which gaseous exchange takes

place across the alveolus.

Sample answer :(Simple) diffusion 1

3

(a)(ii) Able to explain how the process occur

Sample answer :F: Partial pressure of oxygen in the air of alveolus is higher than

in blood capillaryP: (Gas diffuse) follow the concentration gradient

1 + 1


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(b)(i) Able to name blood vessel S

Answer : Pulmonary artery

1

3

(b)(ii) Able to describe the role of blood vessel S in transporting oxygen from alveolus to muscle cell

Sample answer :P1: In the blood, oxygen from alveolus combine with respiratory

pigment / haemoglobin to form oxyhaemoglobin / oxygenated blood

P2: transport oxygenated blood // oxyhaemoglobin to heartP3: the heart pump the oxygenated blood to muscle cells

Any 2

1+1

(c)(i) Able to name process P and process Q

Answer :P : Aerobic respirationQ : Anaerobic respiration

1+1

4

(c)(ii) Able to explain one difference between process P and process Q

Sample answer :P Q

D1 Complete breakdown of glucose

Incomplete breakdown of glucose

E1 Release large amount of energy // 2898 kJ per molecule glucose // 38 molecules of ATP

Release less amount of energy // 150 kJ per molecule glucose // 2 molecules of ATP

D2 Produce carbon dioxide and water

Produce lactic acid

E2 Produced as waste product

Caused muscular cramps/fatigue

D3 Occurs in the mitochondria

Occurs in the cytoplasm

E2 Oxygen is required Oxygen is not requiredAny 2

1+1

(d) Able to explain the statement

Sample answer :F1: (During the vigorous activity) the muscle cells are in a state

of oxygen deficiency / oxygen debt // the blood cannot supply oxygen fast enough to meet the demand for energy / ATP

P1: (The increase in heartbeat rate) is to deliver more oxygen / glucose to muscle cells

P2: to obtain extra energy (from anaerobic respiration) // to increase rate of cellular respiration

P3: to remove more carbon dioxide from the muscle cellsAny 2

1+1

2TOTAL 12


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SULIT 4551/2

Question 4

No Mark Scheme Mark4(a)(i) Able to state type of blood circulatory system shown by

organism P and organism Q.

AnswerOrganism P :Double circulatory system

Organism Q :Single circulatory system 1+1 2

(a)(ii) Able to name one example of organism P and organism Q.

Sample answersOrganism P :Human

Organism Q :Fish

1 + 1 2(b) Able to explain the importance of having the blood

circulatory system to organism P.

Sample answer

F : (double circulatory system ) is more efficient P1: the heart pumps the blood twice / the blood flow into the heart

twice in a complete circulation.P2 : higher pressure of blood can be maintained.P3 : the blood travels more faster to organsP4 : the organs get sufficient amount of glucose / oxygen /

nutrient // the waste product / carbon dioxide / urea can be eliminated out of organ.

Any 3 1 + 1 + 1

3

(c) Able to explain one difference of heart structure between organism P and organism Q.

Sample answerF : heart of organism P has four chamber but organism Q has

two chamberP1: organism P has right atrium, left atrium, right ventricle and left

ventricle but organism Q has ventricle and atrium. // organism P has two atriums and two ventricles but organism Q has one ventricle and one atrium.

P2 : in organism P , the heart receives both oxygenated blood and deoxygenated blood while in organism Q , the heart only receives deoxygenated blood.

Any 21 + 1 2


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SULIT 4551/2

(d) Able to explain why a person needs second injection to maintain the level of immunity

Sample answer

F : booster doseP1 : stimulate lymphocycte to produce more antibodyP2 : to achieve immunity levelP3 : that protect the person against disease

Any 3 1+1+1 3Total 12

Question 5

No Mark Scheme Mark5(a) Able to complete Diagram 5 to show the cross between the

plants

Sample Answer1. RRTT2. rrtt3. Genotype F1 : RrTt4. Phenotype F1 : Red, tall 1+1+1+1 3

(b)(i) Able to Use Punnett Square to show crossing of F1 generation to produce F2 offspring.

Sample answers

Gametes RT Rt rT rtRT RRTT RRTt RrTT RrTtRt RRTt RRtt RrTt RrttrT RrTT RrTt rrTT rrTtrt RrTt Rrtt rrTt rrtt

G : all gametes correct = 1 markC : 14 to 16 genotype correct = 2 marks 4 to 13 genotype correct = 1 mark 1 + 2 4

(b)(ii)

Able to calculate phenotype ratio of the offspring produced in F2

generation

Sample answer

Phenotype: Red, Tall Red, dwarf White, tall White, dwarf

Calculation:9

163

163

161

16

Ratio: 9 3 3 1


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SULIT 4551/2

All phenotype correct = 1 markAll calculation correct = 1 markAll ratio correct = 1 mark

1 + 1 + 1 3(c) Able to explain why some of the offspring produced do not have

same phenotype as their parents.

Sample answer

P1: The dominant allele / R / T will mask/cover the effect of the recessive allele / r / t //any suitable explanation

P2: a recessive allele / r / t only expresses itself when dominant allele / R / T is absent

P3: RrTt represent red flowered tall plant while white flowered dwarf plant are not expressed // any suitable example of genotype and phenotype

Any 2 1 + 1 2Total 12


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SULIT 4551/2

Section BQuestion 6

No Mark Scheme Marks6(a) Able to describe the differences between light reaction and

dark reaction

Sample answers:

Light reaction Dark reactionD1. Occurs in granum Occurs in stromaD2. Requires light Does not require lightD3. Involves photolysis of

waterInvolves reduction/fixation of carbon dioxide

D4. Materials required is water

Materials required is carbon dioxide

D5. Produces oxygen and water

Produces glucose

Any 4

Max 4m

(b) Able to explain how plants grown in greenhouses can ensure the production of crops throughout the year.

Sample answer:F: In temperate countries light intensity / temperature changes

throughout the year.P1: In winter , temperature is very lowP2: In autumn, the plants shed their leaves // Light intensity/

temperature is lowP3: Rate of photosynthesis is very lowP4: In spring and summer, the light intensity/temperature are

optimum for photosynthesis.P5: So the rate of photosynthesis is maximum / highest.P6: In the greenhouse, light intensity/concentration of carbon

dioxide/temperature are maintained at optimum level (for photosynthesis ) throughout the year.

P7: So the rate of photosynthesis is maintained at maximum level throughout the year (regardless of changes in light intensity or temperature).

P8: The plants are able to increase yields / increase the crops production throughout the years.

Any 6

Max 6m

(c) Able to explain the rate of photosynthesis in plant throughout the day

Sample answer:F1: From 0000 to 0600, the rate of photosynthesis is very lowP1: The light intensity / temperature is (very) lowP2: ( At low temperature,) photosynthetic enzymes are inactive.

F2: From 0600 to 1200 , the rate of photosynthesis increase (rapidly)

P3: Light intensity / Temperature also increasesP4: Enzyme for photosynthesis become more active.P5: Stomata open wider to allow absorption of more carbon

dioxide


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SULIT 4551/2

F3: The rate of photosynthesis is maximum / the highest at 1200P6: The light intensity / temperature is optimum (for

photosynthesis).P7: Enzymes are the most active.

F4: From 1200 to 1800, the rate of photosynthesis decreasesP8: Light intensity / temperature decreasesP9: Photosynthetic enzyme are less activeP10: Stomatal openings/pores become smallerP11 : Less carbon dioxide is absorbed

F5: From 1800 to 2300 , the rate of photosynthesis become very low/stopped/ceased

P12 : Light intensity / temperature is very low P13: Photosynthetic enzymes are not activeP14: Stomata closedP15: Very little / no carbon dioxide is absorbed

Any 10

Max 10m

Total 20


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SULIT 4551/2

Question 7

No Mark Scheme Sub mark

Total mark

7 (a) Able to describe how the structures of kidney are adapted to enable them to carry out homeostasis process.

Sample answer

F1 : (each kidney) contains hundreds of thousand / a large number of nephrones

P1 : to filter substances from the blood efficiently.

F2 : (each kidney) has ureterP2 : to carry away the urine / solution of wastes dissolved in

water / creatinine/toxin and drugs

F3 : (each kidney) received blood (that already) under relatively high pressure.

P3 : ultrafiltration can take place efficiently

F4 : the kidney is controlled by negative feedback mechanisms

Any 4

4

(b) Able to describe how the machine used to remove waste product such as urea from person with kidney failure .

Sample answer

P1 : blood from the patient’s artery is passed through a machine

P2 : which contains a dialyser / dialysis solution

P3 : dialysis tubing has a semi-permeable membrane

P4 : concentration of waste molecules / urea in blood is higher than in the dialysis solution // there is concentration gradient between the blood and dialysis solution

P5 : waste molecules / urea / excess salts diffuse through membrane from blood to dialysis solution.

P6 : dialysis solution is continuously being replaced // essential substances remain in the blood.

P7 : plasma protein / red blood cells are not able to diffuse through membrane of dialysis tubing

P8 : because the size is bigger/too big

P9 : the direction of the flow of blood is opposite to the direction of dialysis solution

6


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P10 : to ensure the waste molecule / urea is continuously being remove from blood to dialysis solution.

P11 : the filtered blood re-enters the patients blood vessel

Any 6 (c) Able to explain the differences between the percentage of

chemical substances in blood and urine.

Sample answer

F1 : percentage of water in blood is higher than in urine.

P1 : In the proximal convoluted tubule

P2 : The Na+ are pumped into the capillary // some salts are reabsorbed by a active transport

P3 : The movement of solutes into the capillary network decreases the solute concentration of the filtrate but increases the solute concentration in the capillary network.

P4 : As a result, water diffuses into blood capillaries by osmosis from the proximal convoluted tubule / Loop of Henle / distal convoluted tubule / collecting duct

F2 : Percentage of plasma protein is higher in blood compared to urine // percentage of plasma protein is nil in urine

P5 : size of plasma proteins are larger/too large which cannot be filtered out/diffused out during ultrafiltration.

F3 : percentage of glucose is high in blood but nil in urine

P6 : All glucose are reabsorbed by active transport at proximal convoluted tubule.

F4 : percentage of urea is higher in urine than in blood

P7 : Urea is actively transported from the blood capillary to the distal convoluted tubule.

P8 : by secretion process

Any 10

10

Total 20


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SULIT 4551/2

Question 8

No Mark Scheme Sub Mark

Total Mark

8 (a)(i) Able to explain the cause of the phenomenon and its effect on the environment

C: Causes of the phenomenonE: Effects of the phenomenon

Sample answers

F : This phenomenon is called green house effectC1: Combustion of fossil fuels from vehicles/ factories/

forest burning / coal-fired power stationC2: excessive deforestationC3: increase carbon dioxide concentration in the

atmosphereC4: pollutants/CFC/methane

E1: carbon dioxide traps heat/ infra-red light/ long-wave radiation

E2: increase in global/ world atmospheric temperature/ cause a rise in Earth’s temperature/ global warming.

E3: melting of polar ice/ rise in the sea levelsF with any 5 points 1+5 6

(a)(ii) Able to suggest measures to overcome the phenomenon

Sample answers

P1: use alternative source of energy to reduce the usage of fossil fuels/energy generated from wind / water/ solar

P2: restrict open burning/ forest burning/ use incineratorP3: reduce deforestation for farming/other development

projectsP4: Selective harvesting/logging/cut matured tree onlyP5: replanting more trees which have been cut downP6: the use of technology / unleaded petrol / catalytic

converterAny 4 4 4

(b) Able to discuss the effects of the phenomenon on the lives on Earth.

Sample answers

F: The phenomenon is known as the thinning/ depletion of the ozone layer

P1: More ultraviolet ray reaches the Earth’s surfaceP2: Ultra-violet ray will deteriorate human’s body immune

systemP3: An increase in the number of people suffering from skin

cancer/ melanoma / cataractP4: High ultraviolet rays destroy phytoplanktons


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P5: break the food chain of marine life / the aquatic ecosystem

P6: the number of stomata / chlorophyll of the leaves will be reduced

P7: Rate of photosynthesis decreasesF with any 5P 1 + 5 6

(c) Able to explain the concept of sustainable and its need to protect our environment.

Sample answersF: (Sustainable development refers to) the measures

undertaken to ensure that human activity optimally utilize Earth’s natural resources such that they can be replenished naturally//suitable explanation

P1: Sustainable development is necessary as the rate at which man is using the finite natural resources will compromise future generation’s demands//suitable explanation

P2: Ultimately, the natural resources, if continued to be depleted, will no longer be able to sustain human society//suitable explanation

P3: Sustainable development involves the protection of air/land/water

P4: which make up the surrounding we live in and survive upon.

P5: (It is intimately linked) to the protection of wildlife as wellP6: in order to maintain a stable/balanced ecosystem

F + any 3P 1 + 3 4

Total 20


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SULIT 4551/2

Question 9

No. Mark Scheme Marks9(a)(i) Able to state what fertilisation is

Sample AnswerFertilisation occurs when the nucleus of a sperm and the nucleus of an ovum fuse to form zygote

1

(a)(ii) Able to describe the early development after the formation of a zygote from process I to IV

Sample Answer

Process IP1 : Fertilisation occurs at the fallopian tube to form a zygote

Process IIP2 : the zygote begins to divide by mitosisP3 : known as an embryoP4 : The zygote is divided successively into a solid mass of cellP5 : At this stage, a morula is formed

Process IIIP6 : the morula then divides to form a hollow ball with fluid-filled

cavityP7: called blastocyst//blastula

Process IVP8 : (seven day after fertilisation) the blastocyst implants itself into

the endometriumP9 : The blastocyst/blastula formed has an inner cell mass which

will develop into an embryoAny 7 7

(iii) Able to predict what might happen if the corpus luteum fails to develop after fertilisation.

Sample answer:

P1 : the level of progesterone drops / decreaseP2 : the foetus will be abortedP3 : because the function of progesterone is to maintain

thickening / vascularisation of the endometrium wallAny 2

2(b) Able to describe the in vitro fertilisation technique

Sample answer:F : In-vitro fertilisation (IVF) is the fertilisation of the egg that

occurs outside the human bodyP1 : the wife was injected with hormone to stimulate the

development of the secondary oocyte / ovum in ovariesP2 : secondary oocyte / immature ova are collected by using a laparoscope (from ovary before ovulation)


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SULIT 4551/2

P3 : The immature ova are placed in culture solution to matureP4 : Sperms are collected/placed in the culture solutionP5 : sperms from husband fertilise with the secondary oocyte in a Petri dish (contains culture medium)P6 : (after fertilization) zygote will divide by mitosis P7 : (after 2 days) formed embryo are at eight celled stage P8 : Afew embryos/fertilised ova are transferred into the

endometrium wall of uterus by using catheterP9 : embryos/fertilised ova are implanted into endometrium wall

of uterus and start to developP10 : baby that is delivered is called test tube babyP11 : This technique is complicated / expensive/the probability to success is low

F with any 9 Ps 10

TOTAL MARK 20

PERATURAN PEMARKAHAN TAMAT


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ans p2 johor 2010

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