answer scheme for biol pat 2011 form 4

7/31/2019 Answer Scheme for Biol Pat 2011 Form 4

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UNIT PEPERIKSAAN DALAMANSMKA AL-IRSHADPOKOK SENA , KEPALA BATAS

PEPERIKSAAN AKHIR TAHUNTINGKATAN 4BIOLOGY 4551/2KERTAS 2OKTOBER 2011

2 hours thirty minutes Dua jam tiga puluh minit

JANGAN BUKA KERTAS SOALAN INI SEHINGGA DIBERITAHUINFORMATION FOR CANDIDATES

1. This question paper consists of three sections :Section A and Section B

2. Answer all questions in Section A. Write your answers forSection A clearly in the spaces provided in the question paper

3. Answer TWO question from Section B. Write your answer forSection B on the lines paper in detail. You may use equations,diagrams, tables, graphs and other suitable methods to explainyour answer.

4. Show your working, it may help you to get marks..

5. If you wish to cancel any answer, neatly cross out the answer.

6. The diagrams in the questions are not drawn to scale unlessstated.

7. Marks allocated for each questions or part question are shown inbrackets

8. The time suggested to complete Section A is 90 minutes, SectionB is 60 minutes.

9. You may use a non-programmable scientific calculator

10 Hand in this question paper at the end of the examination

For Examiners Use

Section QuestionFull

MarksMarks

Obtained

A

1 12

2 12

3 12

4 12

5 12

B

6 20

7 20

8 20

9 20

Total 100

Kertas soalan ini mengandungi 15 halaman bercetak

1

Nama :

Tingkatan ..


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SECTION A60 MARKS

Answer all questions

1. Figure 1 shows a typical cell observed under the electron microscope.

FIGURE 1

(a) ( i ) Identify whether it is plant cell or an animal cell

Plant cell

[1 mark]( ii ) Give two reasons for your answer in (a)( i ) .

- has cell wall

- has a single / large vacuole

- has chloroplasts

Any two correct answers

[2 marks]Name the organelles P, Q and R .

P : Vacuole

Q : Mitochondrion

R : Nucleus

[3 marks]

What is the significance of P for the cell ?.

To control the osmotic balance // regulate turgor pressure in the cell.[1 mark]

(d) Explain the function of Q.

- Site for generating energy ( needed )

- for cells activities / cell division / cellular respiration

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P

Q

R

S


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[2 marks]

(e) What would happen to the cell if organelle S is absent?

- Cannot maintain the shape of plant cells

- Cannot protect the plant cell from rupturing ( due to the movement of excess waterinto cells )//

- Cannot provide mechanical support for the plant

cells

[3 marks]

TOTAL: 12 MARKS

2.

a)

Figure 2.1 shows a fluid mosaic model of plasma membrane.

Diagram 2.1

Label structures P, Q, R and S in diagram 1.1 using the following:

P: carrier protein

Q: pore

R: cholestrol

S: phospolipid

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Pore

Cholesterol

Carrier protein

PhospholipidPP


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[4 marks]

FIGURE 2.2

An experiment has been carried out on plant cell, S which is soaked in solution T. The resultis shown in Figure 2.2.

(b) State the type of solution T.

hypertonic[1 mark]

(c) (i) Name the phenomenon that occurs on plant cell S. .

plasmolysis

[1 mark](ii) Explain how does the phenomenon in (c) (i) occurs.

P1: there is a different concentration between inside and outside cellP2: water molecules in the cell diffuse out by osmosis

P3: the cytoplasm contract and the plasma membrane moves away from the cell wall

Any 2

[2 marks]

(i) Draw the shape of the plant cell after it is soaked in distilled water in the space providedbelow.

[3 marks]

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(d) (ii) State the process that takes place in the cell.

deplasmolysis

[1 mark]

TOTAL: 12 MARKS

3. Diagram 3 shows structures of protein. The protein structures can be classified into four levels J

K, L and M based on organization of their structures.

Diagram 3

(a) ( i) Label amino acid and peptide bond in J

X : Amino acid

Y : Peptide bond[2 marks

(ii) Name the protein structures of L and M L: Secondary structure

M: Quaternary structure

[2 marks

(b) (i) Name the organelle in the cell where the protein is synthesized?

Ribosome

[1 mark](iii) By using the letters J,K L and M, which protein structure is represented

Enzyme : K

Haemoglobin : M

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J K L M

X

YYY


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[ 2 marks

(c) Explain why food is kept in refrigerator?

F : Temperature in refrigerator is low

P1 : Enzyme (in bacteria) is inactive P2 : food cannot be decomposed

[3 marks

d) A branded washing machine is provided with temperature regulator. A housewife uses

the detergent containing enzyme at 40oC to wash the clothes. Using the information

given, explain why?

F: 40o

C is an optimum temperatureP1: enzyme activity is maximum

P2: the cleaning is more effective.

[ 2 marks

TOTAL: 12 MARKS

4. Figure 4.1 shows phases U and V of the cell cycle of a cheek cell.

Phase U and phase V are two main phases in the cell cycle.

Phase U consists of three sub-phases, X, Y and Z.

Phase V involves two processes, P and Q

Figure 4.1

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U

V

X

P

Q

Y

Z


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(a) Name the phase labelled U and V.

U : Interphase

V : Mitotic phase // M phase

[ 2 marks ]

(b) (i) Draw and label the cell during U phase.

[ 3 marks

(ii) What happen in the cell during U phase.

Protein synthesis// Number of organelles increases // energy storage

Replication of DNA //

Final preparation of cell for cell division to take place //synthesis of cellular materials//mitotic spindle begins to form// Energy storage increases

Any ONE above

[ 1 mark

(i) Name the processes P and Q in phase V :

P : Mitosis Q : Cytokinesis[ 2 marks

(ii) Figure 4.2 shows a cell which is found in human cheek.

Figure 4.2

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chromatin

Nuclearmembrane

plasmamembrane


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State two characteristics of daughter cells when the cell in Figure 4.2 undergoes P process ?

Number of chromosomes:

The daughter cell has similar number of chromosomes to the parent cell

Genetic content:

The daughter cell has similar genetic content to the parent cell .[ 2 marks

Figure 4.3 shows the formation of cancer cell in the mouth.

Normal cheek cell Cancer cells

Figure 4.3

Based on Figure 4.3 , explain how cancer cell develops ?

F nature of carsinogenic chemicals

Carsinogenic Chemical causes uncontrolled mitosis

E1 formation of cancer cells

Carsinogenic chemical can induce the cheek cell to divide and form cancer cells

E2 its effect to the surrounding cells

Cancer cells interrupt / interfere the function of normal cells

[ 2 marks

TOTAL: 12 MARKS

5. (a) Diagram 5 shows the use and production of energy in human body.

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Carsinogenicchemical


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Diagram 5

(i) Name the processes labeled X and Y.

X : Cellular respiration

Y : Cell activity // muscles contraction[2 marks

(ii) Name the organelle in the cell that is able to synthesis ATP.

.

Mitochondria

[1 mark

(b) State two differences between aerobic respiration and anaerobic respiration when one molecule

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X

A D P ~ P

Y

ATP + P

Glucose + oxygen Carbon dioxide + heat

9


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of glucose is used.

Aerobic respiration Anaerobic respiration

- oxygen is present

- carbon dioxide, water and

energy are produced

- 38 molecules of ATP are

generate

- large amount of energy is

released (2898 kJ)

- in mitochondria

- oxygen is absence

- lactic acid and energy (in muscle cells) or

ethanol, carbon dioxide, and energy (inyeast)

- 2 molecules of ATP are generate

- small amount of energy is released (210

kJ during fermentation) and (150kJ in

muscle cells)

- in cytoplasm

[4 marks

(c) (i) After a vigorous exercise, the oxygen content in human body decrease while the carbon

dioxide content increase.

State the receptor that detect the change of oxygen and carbon dioxide content.

Central chemoreceptors // Peripheral Chemoreceptor // Aortic bodies and Carotid bodies

[1 mark

(ii) Describe how the change of oxygen and carbon dioxide content are regulated by the body.

- The higher level of carbon dioxide in the blood cause the drop of pH value- The drop in pH is detected by Central Chemoreceptor in Medulla Oblongata- Then the Central Chemoreceptor send the nerve impulses to the diaphragm and

intercostal muscle, causing (respiratory muscles) to contract and relax

- Finally, increases the breathing and ventilation rate- Concentration of carbon dioxide and pH value of the blood return to normal levels

[3 marks

(d) (i) Based on your knowledge in Biology, state another situation where our body will give thesame response as in (c)(ii)

Climbing a mountain

[1 mark

TOTAL: 12 MARKS

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SECTION BANSWER ANY TWO QUESTIONS

40 marks

6 (a)

Based on the above statement, explain the necessity for food processing.

[10 marks]

(b)

Type of food Food preservation method

Milk Pasteurisation

Fruits Canning

Meat and fish Refrigeration

TABLE 1

Table 1 shows several methods of food preservation that being used in food processing.Describe how the method can preserve food for along period of time.

[10 marks]

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Food preservation involves methods ofpreparing food to extend the lifespan

and to avoid wastage of food.


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ITEM

NO

SCORING CRITERIA MARKS REMARK

6 (a)

(b)

Able to explain the necessity of food processing

Sample answer

F1 prevent food spoilageE1 (food spoilage) causes by the action of microorganism

E2 decomposing bacteria/fungi on carbohydrate/protein

E3 produced carbon dioxide, water, ammonia hydrogenE4 make food become toxic

F2 Oxidation of food when cut/expose to airE1 oxygen react with enzymes/chemicals released by cell

F3 Increase it commercial valueE1 food additives is added in preserving the freshness of

foodE2 Improve the taste/appearance/texture

F4 Intention of diversifying the uses of food

E1 increased the variety of products

Able to describe how each method can preserve food for along period of

time

Sample answerPasteurisation:

- milk is treated to 63oC for 30 minutes//72oC for 15 seconds

- followed by rapid cooling to below 10o

C- destroy bacterias but not the spores- retains the natural flavour of milk//nutrients//vitamin B

- must refrigerated to avoid the growth of sperms

Canning:- use heat sterilisation

- kill microorganisms and spores

- steamed at high temperature and pressure to drive out air- sealed while the food is being cooled

- vacuum in the can prevent growth of microorganism

Refrigeration:- stored at temperature below 0oC

- prevent the growth of microorganisms/the germination of spores

TOTAL

11

1

11

11

1

11

1

1

1

111

1

1

1

1

1

1

1

1

12

10

Max4

Max4

2

10

13


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7 (a) Briefly describe the respiratory system found in organism Q and R in diagram 7.1 and how theyobtain oxygen for respiration.

[10 marks]

(b) Diagram 8.2 shows gaseous exchange across the surface of the alveolus and blood capillaries in

the lungs. Based on diagram 7.2, explain how respiratory gaseous are transported in humanbody.

[10 marks]

Hjk

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ITEM

NO


7 (a) Able to explain the respiratory system found in grasshopper and fish.

Sample answer

GrasshopperP1- the respiratory system of insects is known as tracheal system

P2- air enters the trachea through spiracles

P3- opening & closing of spiracle is control by valvesP4- the trachea is reinforced with rings of chitin to prevent collapsing

P5- trachea branch into tracheoles which provide a large surface area for

diffusion of gasP6- oxygen then dissolves into the fluid at the end of tracheoles

P7- oxygen diffuse directly from tracheloes into th cells, while carbon

dioxide diffuse out from cells into the tracheloesP8- contain air sacs which speed up the movement of gases to and from

insectss tssue

Any fve

Fish

P9- Respiratory structure in fish is gillsP10- a fish has four pairs of gills covered by an operculum on each side

P11- each gill has two rows of gill filament to increase the surface area

for gaseous exchangeP12- the filament have thin membranes with a rich supply of blood

capillaries to facilitate exchange of respiratory gases

P13- the efficiency gaseous exchange is aided by countercurrentexchange mechanismP14- during inspiration, the mouth opens, buccal cavity expands both of

the operculums are closed. Water enter the mouth

P15- the mouth then closes. The floor of the buccal cavity is raised.Water

Any five

1

1

1

1

1

1

1

1

1

1

1

1

1

1

1

8

5

7

5

15


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ITEM

NO


7 (b) P1- gaseous exchange occurs at alveoli

P2- movement of gases occur through simple diffusion

P3- oxygen from alveoli diffuse to the blood capillaries// carbondioxide diffuse from blood capillaries to the alveoli

P4- diffusion of oxygen from alveoli to blood capillaries andcarbon dioxide from blood capillaries to alveoli caused bydifference in partial pressure of both gases

P5- partial pressure of oxygen in alveoli is higher than partialpressure of oxygen in blood capillaries// while partial pressure ofcarbon dioxide in blood capillaries is higher than partial pressureof carbon dioxide in alveolus

P6- oxygen diffuse into red blood cell

P7- oxygen combined with haemoglobin to form oxyhaemoglobin

P8- oxygen in the form of oxyhaemoglobin is pumped by heart toall body cells

P9-oxygen diffused from blood capillaries to the cell// carbondioxide diffuse from cells to the blood capillaries

P10- carbon doxide is sent to the lungs as bicarbonate ions/carbonic acid/ carbaminohaemoglobin

P11- deoxygenated blood is sent back to the heart by the venacava

P12- Deoxygenated blood is sent to the lung by pulmonary arteryto excrete out the carbon dioxide

Any 10.

1

1

1

1

1

1

1

1

1

1

1

1 12

10

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8 (a) Diagram 8 shows the process of colonization and succession in a barren land.

Based on diagram 8, explain what is meant by colonization and succession and how the processleads to a complex community

[8 marks]

(b) State the problems faced by the mangrove plants grown near the estuaries of rivers.Explain how these plants adapt to survive.

[8 marks](c) Give reasons why the mangrove swamps is ecologically valuable.

[4 marks]

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ITEM

NO


Able to explain what is meant by colonisation and

succession and how the process lead to a complexcommunity

ColonizationIs a process whereby a species colonise a newly formed

area.

Succession

A process when a species of organisms/ changes the

environment/ habitat which results in the species/ organism

being replaced/ succeeded by other species/ community

P1- pioneer species have special adaptation that enable

them to survive on dry and nutrient poor soil

P2- usually hardy plants which have dense root system to

bind the sand particles and hold water as well as humus.

P3- Activities of the pioneer species cause a change in the

habitat making it more suitable for other species

P4- they have short life cycles thus when they die, theyremain add to the humus content of the soil

P5- pioneer species modifies the environment creating a

less favorable condition to themselves

P6- instead, they establish condition that are more

conducive to other species which are called successor

speciesP7- successor species i.e. herbaceous plant grow bigger

than pioneer species i.e. grass, reducing the amount of

sunlight that reaches them and gradually replacing them

P8- most of the successor species have small wind-

dispersable seeds which are able to spread and grow rapidy

P9- they (successor species/ herbaceous plants) also

change the structure and quality of the soil, making it more

conducive for a larger plants like shrubs to grow

1

1

1

1

1

1

1

1

1

1

1

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P10- new plants/ shrubs then become the new dominant

species. They can grow faster and they out-compete the

pioneer/ herbaceous plants which grow at a slower rate

P11- the dominant species in turn modify the environment,allowing larger trees to grow

P12- the larger trees out-compete the shrubs which are

replaced by forest-floor species which require lower lightintensity

P13- Finally, a climax/ complex community is formed

Any 8

1

1

1

1 138

(b) Problems

P1- swamp is muddy, too soft to support the plants

P2- waterlogged soil with little oxygen for plant roots toRespire

P3-water in the soil has high concentration of salt

P4- seeds of plant fall on the soft mud and sink easilyinto the mud/ will not germinate/ die due to the lack ofoxygen in waterlogged mud

Adaptation

P5- mangrove plants are able to support themselves insoft ground by having a highly branched and widespreadroot system. e.g prop roots

P6- have breathing roots called pneumatophores

P7- roots of mangrove trees have higher salt contentthan seawater

P8- excess salt which enters the roots are eliminated via

hydathodes at lower epidermis of leaves

P9- seeds of mangrove trees are viviparous

P10- the germinated seeds having long radical that stillattached at the parent trees

P11- long radical help to support the shoot above muddyground and do not drown or get washed to sea by waves.

1

1

1

1

1

1

1

1

1

1

1

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Any 8118

(c) Able to state the reasons why the mangrove swmps isecologically valuable

P1- provide sheltered nurseries for young fishes, crabsand other sealife

P2- spawning grounds for ishes and crabs

P3- Habitat for variety of animals (eg monkey, bird) livingin the mangrove swamp

P4- help to prevent coastal erosions by sea waves

1

1

1

1 4

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9 (a) (a) Diagram 9 shows the Nitrogen Cycle..

Diagram 9.1

Based on Diagram 9.1, discuss the role of microorganisms in the Nitrogen Cycle. Berdasarkan Rajah 9.1 , bincangkan peranan mikroorganisma di dalam Kitar Nitrogen

[10 marks]

(b) Diagram 9.2 shows the ozone layer in atmosphere that protects earth from ultraviolet

4551/2 21Root nodules

of legumes

Nodul akarkekacang

Urine

Organic materials

Root nodulesof legumes

Ammonium compound

Nitrite

Nitrate

Faeces

Nitrogen in theatmosphere


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rays from the sun.

DIAGRAM 9.2

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]

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Solar radiationSinaran suria

StratosphereStratosfera

Ozone layerLapisan ozon

Harmfulultraviolet radiationSinaran ultra ungu

berbahaya

TroposphereTrofosfera

EarthBumi


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Itemnumber

Criteria Marks Notes

9 (a) F1 - Rhizobium bacteria inside the root nodulesof legumes and Nostoc sp. found freely inthe soil fixed the nitrogen in air

F2 - decaying bacteria / fungi decompose

plant /animal / dead organism / wasteproduct

P1 - to form ammonium compound

F3 - Nitrosomonas sp./ nitrifying bacteriaconverted ammonium compound to nitrite

F4 - Nitrobacter sp /nitrifying bacteria convertnitrite to nitrate

P2 - nitrate is absorbed by plant to form plant

protein

P3 - (plant protein) eaten by an animal to formanimal protein

F4 - Denitrifying bacteria reduce the nitratecontent in the soil

P4 - by converting the nitrate into nitric oxideand nitrogen gas

P5 - nitrogen gas goes back into the

atmospheric to complete the nitrogen cycle

1

1

1

1

1

1

1

1

1

1 10

marks

9 (b)Able to explain how the ozone layer becomes

thinner / ozone depletion occur

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 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

1

1

1

1

1

1Max 5

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Itemnumber

Criteria Marks Notes

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, moreultraviolet radiation reaches the Earth

The effect of excessive ultraviolet radiation on

human

reduction of the bodys 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, fishermans 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

1

1

1

1

1

1

1

1

1

1

1

Max 3

Max 2

TOTAL10marks

Disediakan oleh, Disemak dan Disahkan oleh,

.. .(NUR HAFEZA BT ABU HASSAN) (Salahiah Bt Daman)Guru Biologi Tingkatan 4. Guru Kanan Bidang

Sains & Matematik.

answer scheme for biol pat 2011 form 4

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