SULIT 4551

Section A[ 60 marks ]

Answer all questions in this section

For Examiner’sUse

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

…………………………………………………………………………………..

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

.…………………………………………………………………………..

……………………………………………………………………………… [2 marks]

(b) Name the organelles P, Q and R .

P : …………………………….………………………………………………..

Q : …………………………….………………………………………………..

R ; ……………………………..……………………………………………...

[2 marks](c) What is the significance of P for the cell ?.

………………………………………………………………………………..

[1 mark]

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PQ

R

S

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(d) Explain the function of Q.

………………………………………………………………………………

………………………………………………………………………………

[2 marks]

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

..……………………………………………………………………………….

..………………………………………………………………………………

……………………………………………………………………………….

[2marks]

(f) Explain one different between a root hair cell from the plant cell in

Figure 1

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……………….

…………………………………………………………………………..

[2 marks] TOTAL

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2 Diagram shows part of the stages of meiotic cell division in an animal cell.

The chromosome behaviour in stage S is not shown.

Meiosis1

Meiosis 11

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XStage P

Stage Q

Stage R

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Diagram 2.1

(a) Name the structure labeled X.

……………………………………………………………………………………. [1mark]

(b) (i) In Diagram 2.1, complete the diagram in stage S to show the

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Stage S

Stage T

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chromosome behaviour. [1 mark]

(ii) State the chromosome activity in stage S.

…………………………………………………………………………………….

……………………………………………………………………………………. [1 mark]

(c) Diagram 2.2 shows process Y which takes place in stage P

Diagram 2.2

(i) In Diagram 2.2, draw a diagram showing the appearance of the chromosomes at the end of process Y. [

1 mark]

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Beginning of Process Y

End of Process Y

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(ii) Name the process Y.

……………………………………………………………………………… [

1 mark](iii) State one importance of process Y to an organism.

……………………………………………………………………………………

…………………………………………………………………………………… [

1 mark]

(d) Diagram 2.3 shows skin cells. Cells L are cancerous cells which are formed after normal cells are exposed to factor K.

Diagram 2.3

(i) Give two examples of factor K.

1. ……………………………………………………………………………

2 .…………………………………………………………………………… [2 marks]

(ii) Explain the formation of cells L.

……………………………………………………………………………………

……………………………………………………………………………………

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Cell L

Normalcell

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………………………………………………………………………………….. [2 marks]

(iii) State two ways to prevent the development of cells X.

1. …………………………………………………………………………

…………………………………………………………………………

2. …………………………………………………………………………

………………………………………………………………………… [2marks]

3 Diagram 3.1 shows human digestive system.

DIAGRAM 3.1

Structure W in Diagram 3.1 involved in the digestion of sugar.

(a) (i) Name structure W.

…………………………………………………………………………[1 mark]

(ii) Name the enzyme which digests sugar in W.

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Duodenum

W

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…………………………………………………………………………[1 mark]

(b) (i) The action of enzyme named in a (ii) above follows a mechanism “ Lock and Key” hypothesis. Diagram 3.2 shows an incorrect steps of the mechanism.

+ +

DIAGRAM 3.2

Rearrange the steps of the enzyme action mechanism in a correct order

……..……………………………………………………………………[1 mark]

(ii) Name one product of the reaction in Diagram 3.2

……..……………………………………………………………………[ 1 marks]

(c) (i) Explain how fat is digested in the duodenum.

……..……………………………………………………………………………

……..……………………………………………………………………………

……..……………………………………………………………………………

……..……………………………………………………………………………[ 2 marks]

(ii) A student student eat too many oranges Explain the effect of eating too many oranges on the digestion of fat in the duodenum.

……..……………………………………………………………………………

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steps :

Enzyme Product

Q Sugar

1 II

P

III IV V

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……..……………………………………………………………………………

……..……………………………………………………………………………

……..……………………………………………………………………………[2 marks]

(d ) In a food preparation process, a housewife carries out the following step:

Step 1: Marinate pieces of meat with strips of unripe papaya in a basin.Step 2: Immerse the basin in a container filled with water at 400 C for

30 minutes as shown in Diagarm 3.3

DIAGRAM 3.3

By using your knowledge in Biology, explain the steps taken by the housewife. ….……………………………………………………………………………

…..……………………………………………………………………………

…..……………………………………………………………………………

…..……………………………………………………………………………

…...……………………………………………………………………………

…..…………………………………………………………………………… [ 4 marks]

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Basinwater

unripe papaya

pieces of meat

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4 Diagram 4.1 shows the release of gas from Elodea sp. through photosynthesis.

Diagram 4.1

(a) (i) Name gas X.

.…………………………………………………………………………………[1 mark]

(ii) What is the function of the sodium hydrogen carbonate solution?

…………………………………………………………………………………[1 mark]

(b) (i) Explain briefly how gas X in (a) (i) is produced.

…………………………………………………………………………………

….………………………………………………………………………………

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0.1% Sodium hydrogen carbonate solution

Light source

Gas X

Elodea sp.

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[3 marks]

( c) An Elodea sp. plant which was placed 10 cm from a light source produced 20 oxygen bubbles per minute.

How many oxygen bubbles per minute would you expect to be released if the lamp is placed at 5cm from Elodea sp.? Show your calculations.

[2 marks]

(d) An experiment was carried out to study the effect of temperature on the rate of photosynthesis. The results are as shown in Table 4.2.

Temperature (0C)

Number of bubbles

25 1030 1535 2040 2545 1550 5

Table 4.2

Explain the above result.

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….………………………………………………………………………………

……………….…………………………………………………………………

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…………………………………………………………………………………[3 marks]

( e ) Diagram 5.2 shows a graph of the effect of light intensity on the rate

of photosynthesis.

Diagram 5.2

State how the rate of photosynthesis can be increased from curve P to

become curve Q ….…………………………………………………………………………………

….….………………………………………………………………………………

………………….…………………………………………………………………

[ 2 marks]

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Rate of photosynthesis

light intensity

Q

P

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5. Diagram 5 illustrates the energy flow through a food web of a terrestrial ecosystem

Diagram 5

(a) (i) Producers convert light energy from the sun and store it in their tissues through a process. Name the process.

………………………………………………………………………………… [1 mark]

(ii) Calculate the percentage of light energy from the sun that is converted and stored in the producers’ tissues.

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Sun

Producer6 x 104 k Jin plant tissue

Herbivor5 x 103 k J

in animal tissue

Carnivore30 k J

in plant tissue

Parasites

Organism P

3 x 108 k J m-2 year-1

to the ecosystem

Ion NO-3 and NH+

4 in soil

Key: Energy flow within the ecosystem Energy flow out of the ecosystem Energy in dead material

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= ……………% [2 marks]

(iii) State one reason why not all of the light energy from the sun is converted and stored in the producers’ tissues.

…………………………………………………………………………… [1 mark]

(b) (i) How much energy from the herbivores’ tissues is not being utilized in the building of tissues in the carnivores?

= ………………kJ [1 mark]

(ii) State what happens to the energy that is not utilized in the building of tissues in the carnivores.

..………………………………………………………………………………

..………………………………………………………………………………

[1 mark]

(c) A pesticide is a chemical compound used to kill pests. The excessive use of pesticides has almost killed all of organism P.By using the information in Diagram 3, describe how this reduces the

production of protein in the producers.

………………………………………………………………………………

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……………………………………………………………………………… [2 marks]

(d) (i) Name one example of a parasite in Diagram 3.

………………………………………………………………………………… [1 mark]

(ii) When the parasites are eliminated from the ecosystem, the producers, herbivores and carnivores are found to be healthier. State your reason.

………………………………………………………………………………

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..…………………………………………………………………………….

[1 mark]

( e ) By using the information in Diagram 3, construct a pyramid of energy for that ecosystem.

[2 marks]

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Section B[ 40 marks ]

Answer any two questions from this section.

6 (a) Diagram 6.1 shows the structures of a unicellular organism which lives in a freshwater pond.

Diagram 6.1

Explain the function of Z in osmoregulation.[4 marks]

(b) Explain the similarities and differences between facilitated diffusion and active transport in the movement of molecules across the cell membrane.

[8 marks]

(c) Diagram 6.2 and diagram 6.3 show two ways of preserving fish and vegetable.

Explain how the preservatives are effective in preservation of each type of the food.[8 marks]

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Z

Diagram 6.2 Diagram 6.3

vinegar Salt solution

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7 (a) Describe the similarities and differences between the structure of digestive and

digestion process of ruminant and rodents based on Diagram 7.1.

Diagram 7.1[10 marks]

(b) Siti takes full cream milk, fried egg and roasted bread as her breakfast this morning. Describe the digestion and absorption take place after that.

[10 marks]

8 (a) Diagram in Table 8.1 shows tissue M and cell N. M is found in a multicellular organism and N is found in a unicellular organism.

Tissue M Cell N

Respiration equation

Glucose + Oxygen Carbon dioxide + Water + Energy

Respiration equation

Glucose Carbon dioxide + Ethanol + Energy

Table 8.1

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Based on Diagram 8.1, explain the cellular respiration process that occurs in M and N.

[4 marks](b) Diagram 8. 2 shows two individuals, X and Y, in two different situations. X is in a vigorous activity while Y is at rest.

Diagram 8.2

Based on Diagram 8.2, explain the different in the physiological process that occurs in organs R, S and T, for individual X and Y

[6 marks]

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Individual X Individual Y

R

S

T

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(c) Diagram 8.3 show a human circulatory system.

DIAGRAM 8.3

Based on Diagram 8.3, explain how the respiratory gases being transported in

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human body. [10 marks]

9 The size of the human population has been rising exponentially. People must obtain all the basic need for their life. Human activities can affect the environment. We must protect our ecosystem before it is too late.

Diagram 9

Diagram 9 shows the human activities.

a) Identify the human activities that can threaten /impact our ecosystem and suggest measures to be taken to ensure a balanced of nature is maintained.

[10 marks ]

b) Discuss the effects of unplanned development and mismanagement to the well- being of man and his ecosystem.

[10 marks]

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END OF QUESTION PAPER

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