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PERFECT SCORE BIOLOGY 2011

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BAHAGIAN SEKOLAH BERASRAMA PENUH DAN

SEKOLAH KECEMERLANGAN

KEMENTERIAN PELAJARAN MALAYSIA

PERFECT SCORE BIOLOGY

2011 Teacher’s Module

Paper 2

Section B


2

Paper 2 – Section B:

1. Diagram 1.1 show the human digestive system and Diagram 1.2 show the structure

inside organ P.

No Essay Questions Marks Student notes

1(a)(i)

Explain the process of absorption of glucose and amino acids in

organ P.

[4 marks]

Sample answer

F1: involve process diffusion and active transport

P1: from the lumen into epithelial cell by facilitated

diffusion

P2: across the epithelial lining by active transport

P3: both are absorb into blood capillaries

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4

1(a)(ii)

Explain three structural adaptation of organ P for effective

absorption of food

[6 marks]

Diagram 1.1

Diagram 1.2

Organ R

Organ P


3

Sample answer

F1: the largest section of alimentary canal

P1: increases the surface area of absorption

F2: Inner surface has numerous number of villi

P2: Form brush border to increase the surface area of

absorption

F3: Epithelial lining is only one cell thick

P3: Increases the rate of diffusion process

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1(b) Describe the process of assimilation in organ R.

[10 marks]

Sample answer

P1: organ R is a liver

P2: act as a checkpoint // control the amount of

nutrients released into blood circulatory

P3: involve in assimilation of amino acids and glucose

P4: (organ R) synthesizes plasma protein from amino

acids

P5: converted amino acids into glucose when a short

supply of glucose/glycogen

P6: broken down/ convert excess amino acids through

deamination

P7: to form urea as waste products

P8: glucose is used for respiration

P9: excess glucose is converted into glycogen and

stored

P10: if full, excess glucose is converted into lipids

P11: glycogen is converted back into glucose if needed

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Any 10

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2. Diagram shows various processed food on a supermarket shelf.

Salted plum Potato chips Prawn crackers


2(a)

Based on your biology knowledge,

Explain the good and the bad of food processing on human being.

[10 marks]

Sample answer

Good(G) Explanation(P)

G1 ; to preserve food P1: Avoid wastage of

food/prevent food

spoilage/can be stored(for

future use)

G2: to increase its

commercial value/uses of

food additives

P2: improve the

taste/appearance/texture of

food/to preserve the

freshness

G3:to diversify the uses of

food substances

P3: to increase the variety of

product//any example

Max ; 5 marks

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1,

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5


5

Sample answer

Bad(B) Explanation(P)

B1 ; uses food additive P4:give long term side

effect/examples//reduce the

nutrient/vitamin in the food.

B2: too much sugar P5: increases the risk of

diabetes

B3: foof colouring/yellow

dye/tetrazine

P6: causes allergy reaction

B4: too much salt P7:increase the risk of high

blood pressure

B5: Sodium nitrate P8:causes nausea/athma(to

certain people)

Any 3B with respective P

Max 5 marks

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5

(b)

Explain the food processing methods which are related to the factors that cause food spoilage.

[ 10 marks]

Sample answer:

Concept : Food can be preserved by destroying the microorganism present in the food // by stopping the activities of the microorganism F1: Cooking-.high temperature kill the microorganisms P1: denature the enzyme that cause the breakdown of food F2: Treating food with sugar/salt P2: causes the microorganism to lose water due to osmosis F3: Adding vinegar will reduced the pH P3 that prevent microorganism from growing F4: Fermentation of fruit juices and other food by adding yeast P4: high concentration of alcohol prevent the microorganism from growing

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F5: Dry under hot sun (meat/fish/fruits) P5: removes water from food – dehydrated F6: Ultravoilets rays P6: kills microorganism F7: Pasteurisation – destroy bacteria which cause tuberculosis and typhoid P7: (technique) -Food is heated to 630C for 30 minutes / 720C for 15 seconds followed by rapid cooling to 10 0C P7.1: (Pasteurisation) retains the natural flavour and nutrients F8: Canning – uses heat sterilization to kill microorganisms and their spores P8 (technique) -.Food is packed in cans, steamed at high temperature and pressure to drive out air P8.1: the vaccum created within the cans prevent growth of microorganism F9: Refrigeration P9: food stored at temperature below 00C prevent growth/germination of microorganism P9.1: food remain fresh for a long period of time Any ten : F + P correctly

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TOTAL MARKS

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7


3

Diagram 3 shows roots of plants found in mangrove swamp.

Discuss how these roots are adapted for stability, salt tolerance and less oxygen of water logged mangrove swamp soil.

[10 marks] Sample Answer: F1: Root adaptations increase stability of mangrove trees in the soft sediments along shorelines. P1: Prop roots descending from the trunk and branches, providing a stable support system. P2: Shallow wide spreading roots, surrounds the trunks of Avicennia adding to the structural stability of the tree. P3: Other species of mangrove trees grow at higher elevations, in drier soils, do not require specialized root structures.

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Pneumatophore


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F2: The ability to exclude salts occurs through filtration at the surface of the root. P1: The cell sap is hypertonic to sea water, the water able to diffuse into the root cell by osmosis P2: Salt is removed through hidatodes located on each leaf.

F3: Mangrove trees are adapted for survival in oxygen-poor sediments through specialized root structures / pneumatophore. P1: these spaces in soil fill with water, containing lower oxygen levels than air.

P2: having well-developed aerial roots or pneumotophores gases exchange

P3 : example Avicennia

P4 : Red mangroves / Rhizophora have prop/stilt roots extending from the trunk and adventitious roots from the branches able to absorb more water and mineral. P5 knee root and buttress root has lenticels that allow air into the roots.

Any 10 points.

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4.

Diagram 4 shows part of a nitrogen cycle .

(a)(i) The atmospheric nitrogen cannot be absorbed directly by plants. Based on Diagram 4, state two form of nitrogenous compounds that can be absorbed directly by plants and explain how a deficiency of substances K in the soil affect the growth of the plants.

[ 4 marks]

Sample answer:

P1 : (Two form of nitrogenous compound that can be absorbed directly by plants) are nitrate ions and ammonium ions. P2 : substances K is nitrate P3 : Substance K is used in synthesis of protein in plant or animal

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Nitrogen in the atmosphere

Substance K

Nitrogen fixation by microorganisms in plant

Nitrites

Ammonium compounds

Nitrogen compounds in

plants

Nitrogen compounds in

animals

Diagram 4


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P4 : (deficiency of substance K), less synthesis of protein P5 : plant growth is retarded/slow/ stunted

[ 4 marks]

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(ii) Based on Diagram 4, explain role of the microorganism in nitrogen cycle.

[6 marks]

Sample answer:

P1 : Rhizobium sp. (in root nodule of legume plant)// Nostoc sp.//Azotobacter sp. P2 : fix the Nitrogen from atmosphere into nitrate/ substance K. P3 : (Nitrate/K substance) is absorp by roots of plants and converted into protein. P4 : (when the plant /animal die), protein in plant/ animal is decomposed by decomposer/fungi P5 : into ammonium compound P6 : Nitrosomonas sp. converts ammonium compound into nitrite P7 : Nitrobacter sp. Convert nitrite into nitrate/substance K P8: Denitrifying bacteria convert nitrate back into Nitrogen

[Max : 6 marks]

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5.

(a)

Diagram 5 shows the eutrophication process that occurs to a lake due to the human activities.

Based on the Diagram 5, explain what is meant by `eutrophication`

[10 marks]

Sample answer

P1 : Farmers use fertilizers that usually contains nitrates/phosphate

P2: Fertilizer/animal waste/silage which contain

nitrate/phosphate may washed out in water when it rains/ leaching/run into the lake.

P3: Algae/green plant in the lake grow faster (when they are

supplied with extra nitrate/(phosphate) P4: (they may grow so much) that they completely cover the

water.

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P5: block out the light for plants growing beneath them.

P6: Photosynthesis rate reduced

P7: Dissolve oxygen also reduced

P8: Plant on the top of water and beneath water eventually die.

P9: Their remains are good source of food bacteria //bacteria

decomposed the dead plant rapidly//bacteria breed rapidly

P10: The large population of bacteria respires using up more

oxygen P11: so there is very little oxygen left for other living

organism P12: BOD increased

P13: Those fish which need oxygen have to move other areas or die

Any 10

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(b)

Explain how each of the following can reduce water pollution:

(i) Treating sewage (ii) Using organic fertilizers rather than inorganic ones.

[6 marks] Sample answer: (i) Treating sewage

P1: The sewage contains harmful bacteria /substance which provide Nitrate/nutrient for microbe.

P2: Remove harmful bacteria/most of the nutrient which

could course eutrophication before it is released into the rivers.

P3: When sewage has been treated, the water in it can be

used again//sewage treatment enables water to be recycled.

P4: Microorganisms used in sewage treatment.

Any 3

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(ii) Using organic fertilizers rather than inorganic

Sample answer

1. Example of organic fertilizers : Manure

2. Example of inorganic fertilizer : Ammonium nitrate

3. Organic fertilizers do not contain many nitrates(which can easily be leached out of the soil.

4. They release their nutrients gradually (over a long period

of time) giving crops time to absorb them efficiently.

Any 3

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(c) Explain how deforestation of rainforest can cause flash flood.

[4 marks] Sample answer

F: deforestation can cause soil erosion

P1 : The leafy canopy trees protect the soil from the impact of falling rain.

P2: The roots of the trees hold soil and water

P3: (With the trees removed) the soil is exposed directly to the rain//water runoff becomes intense.

P4: Topsoil/fertile layer, get washed away during heavy rain.

P5: (heavy rainwater flows down hillside to river with) eroded soil deposited blocking the flow of water.

P6: The water levels in rivers rise rapidly causing flood to

occur.

Any 4

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No Essay Questions

Marks Student notes

6(a)

Diagram 6.1 shows the mankind activities.

Based on your knowledge in biology, explain the effects of the activities to the mankind and their surroundings. Suggest the ways to overcome this problem.

[12 marks] Sample Answer P1: the problem is green house effect

P2: the activities produce green house gases such as carbon dioxide, methane and nitrogen dioxide.

P3: The gases accumulate and forms a layer at the atmospheric surface

P4: Solar radiation penetrate earth atmosphere and warm the

earth surface.

P5: Part of the heat energy is reflected back by earth surface to the atmosphere in the form of infrared radiation.

P6: Heat energy that is reflected back is trapped by

greenhouse gases.

P7: Higher concentration of greenhouse gases on the

atmosphere cause more reflected energy being trapped.

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P8: This will increase the earth temperature and can cause

global warming.

Any 5 The Effect: P1: Increase of carbon dioxide and temperature of earth will

increase the rate of photosynthesis or agriculture yield. P2: Increase in earth temperature / global warming will

accelerate evaporation of water and reduce soil humidity.

P3: Climate change / changes in wind direction / change the distribution of rainfall / drought /flood

P4: Melting of ice in north and south poles increase the sea level and cause flooding of low level areas.

P5: Yield of crop / domestic animal reduced

P6: Mass destruction of animal habitat and cause the animal emigration/ reduces of animal population.

Any 5 Ways to overcome: Use of technology such as : P1: less the emission of CO2 by the motor vehicles by using

the unleaded petroleum. P2: using the filter on the chimney to prevent harmful gases P3: car pool/ use public transporti P4: less open burning P5: less the using of CFC and change to HCFC P6: Using catalytic converter in the car exhaust P7: educate the public on the importance of protecting and

caring the environment through mass media and environmental campaigns.

P8: planting more tree

Any 2

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7(a) . Diagram 7.1 shows the ozone layer in atmosphere that protects earth from ultraviolet rays from the sun.

Diagram 7.1 Describe how the ozone layer becomes thinner. Discuss its effects on humans and the environment and suggest the ways to solve these problems.

[10 marks ]


7 (a)

Sample Answer

Thinning of the ozone layer is due to the widespread use of CFC

It is used in aerosol, industrial solvents, electronics and Freon in air conditioners

Ultraviolet radiation strikes a CFC molecule

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Solar radiation Sinaran suria

Stratosphere Stratosfera

Ozone layer Lapisan ozon

Harmful ultraviolet radiation Sinaran ultra ungu

berbahaya

Troposphere Trofosfera

Earth Bumi


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cause the chlorine atom to break away

Then the chlorine atom collides with an ozone molecule and combines with an oxygen atom to form chlorine monoxide and oxygen

Then the free atom of oxygen collides with the chlorine monoxide, the two oxygen atoms form a molecule of oxygen

The chlorine atom is released and free to destroy more ozone molecules

The chlorine produced re-enters the cycle

When the ozone layer becomes thinner, more ultraviolet radiation reaches the Earth

The effect of excessive ultraviolet radiation on human

reduction of the body’s immune system

skin cancer

cataract of the eye

Effect on plants

reduction of the rate of growth therefore reducing crop yields

Effect on aquatic organism

death of plankton, reduce food supply to aquatic organism, fisherman’s catch is reduced.

Steps to overcome this problem

Reduce or stop using CFC or chlorine-based products

Replace CFC with HCFC

Use wrapping papers instead of polystyrene boxes

Patch up the holes in the ozone layer by firing frozen ozone balls into the atmosphere

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Max 5 Max 3 Max 2 TOTAL 10marks


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7 (b) Diagram 7.2 shows a phenomenon X that occurs from air pollution. Describe the

formation and the effects of the phenomenon on agriculture and aquatic ecosystem.

[10 marks]


9(b)

Able to name the phenomenom X

Sample Answer

F1 : X is acid rain

P1 : combustion of fossil fuels in power station/factories/domestic boilers

P2 : produce sulphur dioxide

P3 : and oxide of nitrogen

P4 : both gases combine with water vapour

P5 : form sulphuric acid and nitric acid

P6 : fall to the Earth with pH less than 5.0

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Max 6

Diagram 7.2


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Effects:

On agriculture

P1 : soil become acidic// leaching of minerals

P2 : not suitable for culativation/grow of crops

On aquatic ecosystem

P1 : accumulation of insoluble aluminium ion in

water sources// increase acidity in the

ecosystem

P2 : kill aquatic organisms

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Total 10 marks


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8. Diagram 8 shows three types of neurone in individual A.

Diagram 8

a) Describe the process X in Diagram 8

[4 marks]

b) Explain the above situation.

[6 marks]

X

Neurone P

Neurone Q

Neurone R

After an accident , individual A doesn’t experience any response to hot object.


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8 (a)

Sample Answer

• When an impulses arrives in the axon terminal

• Stimulates (synaptic) vesicles to move towards and bind with the presynaptic membrane • The vesicles fuse / release the neurotransmitter into the synapse • The neurotransmitter molecules across the synapse to the dendrite of another neurone • Stimulated to trigger a new impulses which travels along the neurone

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Max 4

(b)

SampleAnswer

F1 - P is afferent neurone which transmits nerve

impulse from the receptors to the interneurone. P1 - If P damaged, impulse from receptor cannot be transfered to the interneurone. P2 - (As a result), individual A cannot feel any pain P2 - R is efferent neurone which transmits nerve impulse from interneurone to the effector P1 - If R damaged, impulse from interneurone cannot be transfered to the effector P2 - (As a result), individual A cannot withdraw the finger // pull the hand away from the pointed needle

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9

Mr. Q is married to Mrs. Q for more than 10 years but did not have any child due to low sperm count in Mr. Q. Mr. and Mrs. V have 6 children in 12 years of marriage. Mrs. V has high blood pressure and heart problem, so they decided not to have any more kids. Explain how reproduction technologies able to help these two families.

[10 marks]

Sample Answer F1: Mr Q have problem with infertility, that is low sperm count P1: not enough sperm/ less sperm produce by Mr Q/ less chance for the sperm to reach fallopian tube F2: technology applied : in vitro fertilization P3: sperm and egg are taken from Mr. and Mrs. Q P5: fertilize in petri dish/test tube P6: embryo is inserted into Mrs Q uterus for further development.

or F2: artificial insemination P3: sperms are collected until the number of sperms are enough P4: sperms are injected into the fallopian tube of Mrs Q P5: during ovulation

Any 5 points – 5 marks

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Sample Answer

F3: For Mr V family the problem is to control the birth rate/ stop pregnancy P1: Mrs. V have high risk if pregnant due to high blood pressure and heart problem P2: use contraceptive pills, to stop ovum development P3: use condom during copulation, prevent sperm from reaching uterus P4: Tubal ligation or tubectomy – the fallopian tube is tied/cut P5 : blocking the ovum from entering the uterus/ Prevent sperm from reaching the ovum

Any 5 points – 5 marks

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No Essay Questions Mark Student notes

10.

The variation of ABO blood group determined by three different alleles, but an individual carry only two of the three allele. With schematic diagram , explain the possibilities of the blood group and genotypes of the offspring if the father’s blood group is A and the mother’s blood group is AB.

[10 marks] Sample Answer

Schematic diagram:

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Father Mother X Parent :

IB

Phenotype F1: Blood group A

Blood group B

Parent

genotype : X IA I

A

I

A I

B

Parent

genotype :

Meiosis

Gamete : IA

IA

Fertilisation

Genotype F1: IA I

A

IA I

B

Phenotypic Ratio: 1 blood group A : 1 blood group B

Phenotypic Ratio: 2 blood group A : 1 blood group A : 1 blood group AB

IB

IB I

o

Parent

genotype : X IA I

o

IA I

B

Parent

genotype :

Meiosis

Gamete : IA

IA

Fertilisation

Genotype F1: IA I

A

IA I

B

Io

IA I

o


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Explain : P1 : Allele IA and IB are codominant. P2: Father has 2 possibilities of genotype P3 : (either) IA IA //homozygous dominant or IA Io // heterozygous P4 : (if genotype of father is IA IA ), possibility of blood group of offspring is 50% blood group A and 50% is blood group B//refer to schematic diagram P5 : (if genotype of father is IA Io ), possibility of blood group of offspring is 50% blood group A , 25% is blood group B and 25% blood group B //refer to schematic diagram

[Total : 10 marks]

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11. (a).

Diagram 11.1 shows a group of boys with different height and Diagram 11.2 shows the various types of fingerprints.

Diagram 11.1 Diagram 11.2 Based on the biology knowledge, identify the variation and explain the similarities and differences in Diagram 11.1 and Diagram 11.2.

[10 marks]

Able to: (i) Identify the continuous variation and discontinuous variation.

(ii) Explain the similarity and the contrast of continuous variation

and discontinuous variation.

Sample answer: P1: Diagram 11.1 (height) is continuous variation P2: Diagram 11.2 (fingerprints) is discontinuous variation Similarities: P3: Both create varieties in the population of species P4: Both type of variation are caused by genetic factor Differences: P5: Height is continuous variation while fingerprints is

discontinuous variation P6: Graf distribution of continuous variation shows a

normal distribution while Graf distribution of discontinuous variation shows a discrete distribution.

P7: The characters of continuous variation are quantitative

/ can be measured and graded from one extreme to the other while the characters of discontinuous variation are qualitative / cannot be measured and graded from one extreme to the other.

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P8: Continuous variation exhibits a spectrum of

phenotypes with intermediate character while discontinuous variation exhibits a few distinctive phenotypes with no intermediate character.

P9: Continuous variation influenced by environmental

factors while Discontinuous variation is not influenced by environmental factors.

P10: In continuous variation two or more genes control the

same character while In discontinuous variation single genes determines the differences in the traits of the character.

P11: In continuous variation the phenotype is usually

controlled by many pairs of alleles while in discontinuous variation the phenotype is usually controlled by a pair of alleles.

Any 10

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(b).

Diagram 11.3 shows the variants P, Q and R of a species of fish.

Describe how the variation occurs in the species of fish.

[10 marks] Sample Answer F1: Variation occurs because of genetic factors P1: By crossing over P2: during prophase I of meiosis P3: when two homologous chromosomes are intertwine

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between the non-sister chromatid. P4: the exchange of materials between the chromatids

results in new combination of genes P5: By independent assortment P6: during metaphase I of meiosis, homologous

chromosomes arrange themselves randomly at the equator

P7: the random arrangement and separation of each

homologous pair is independent of one another P8: and result various genetic combination in the gametes. P9: By random fertilisation P10: the fertilisation of sperm and ovum occurs randomly P11: each gamete has unique combination of genes that

can fertilise any of the ova which also has unique combination of genes.

P12: the fertilisation of gametes produced zygote/offspring

which has various of variation. F2: by environmental factors. P13: environmental factors that cause variation included

abiotic factors P14: such as light intensity / temperature / water / humidity

/ nutrients / soil fertility P15: these factor affect the growth rate of the organism.

Any 10

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12 Diagram 12.1 shows a mangrove swamp forest and Diagram 12.2 shows the same area 50 years later.

Diagram 12.1 Diagram 12.2 Discuss the impact of the exploitation on the ecosystem. [10 marks] Sample answer: P1: swampy area is change to densely populated / town /

commercial area P2: the change requires activities such as deforestation and

land reclaimation P3: more and more buildings/ glass buildings built in the are P4: could be the factors for air / thermal / noise pollution P5: and greenhouse effect as well as heat island P6: lost of vast quantity of flora and fauna / biodiversity in the area P7: less water catchment area / less of reproductive area P8: landslide and soil erosion P9: which frequent flash flood and muddy flood P10: water pollution in the nearby river P11: which kill most of the aquatic organisms

Any 10

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