bengkel peperiksaan amali spm(1)

8/10/2019 Bengkel Peperiksaan Amali Spm(1)

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PEPERIKSAAN AMALI SPM

TING 4 BAB 6 NUTRISI

QUESTION 1

( 20 MARKS)

Energy is needed to perform physical activities. The energy required by the body is generated by theoxidation of molecules obtained from food during cellular respiration. The energy content of a particular foodcan be measured by burning a known mass of the food completely in the presence of oxygen. The amount ofheat generated from the combustion of one gram of food is known as the energy value of the food. The unitused to describe energy values in food is joule per gram (Jg -1).

Energy content of foods can be determined by using a laboratory experiment.The aim of this experiment is to determine and compare the energy content in food samples P A and P B.You are provided with distilled water, food sample A and B, plasticine.

Diagram 1

Based on diagram 1, plan and carry out the experiment to determine and compare the energy content in foodsamples P A and P B.Diagram 1 shows the set up for this experiment.Carry out this experiment by using the following steps:

i. Weigh the food sample P Aand record the mass.ii. Fill one boiling tube with 20ml of distilled water.

iii. Set up the apparatus as shown in diagram 1.iv. Record the initial temperature of the water.v. Burn the food sample P Aand put it as near as possible to the bottom of the boiling tube.

vi. Stir the water.vii. The thermometer must not be allowed to touch the base of the boiling tube.

viii. Read and record the highest temperature when the food sample P A has stop burning.


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ix. Repeat step i till viii to get the average temperature rise for food sample P A. x. Repeat step I till ix by using food sample P B.

Based on the experiment which have been carried out, answer the following questions:a) Construct a table and record your readings.

3m

b) State why the temperature of the distilled water increased?

1mc) Calculate the energy value of food sample P A.

2md) State a reason why thermometer cannot touch the bottom of beaker.

1me) (i) If sample food P Ais replaced by cashew nut, predict the energy content of cashew nut.

1m(ii) Give reason for your answer.

1m


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f) Based on this experiment, state the operational definition of energy value.

2m

g) You are required to repeat this experiment by replacing food sample P A with food sample P B. Explain the difference in the energy content of food sample P A and food sample P B.

2mh) Margarine, rice, palm oil, boiled potato, cashew nut and maize .

Classify the food samples into two food classes in Table 1, based on the energy value that is equivalent to thatof white bread or peanut.

Food samples with equivalent energy value as

white bread peanut

Table 12m

i) (i) Based on this experiment, state the following variables:Manipulated variable :

Responding variable:

2m(ii) State the hypothesis for the experiment in 1 (i) (i).

3m


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QUESTION 2

(10 MARKS)

2. This experiment is carrying out to study sex determination in offspring.White button represents an ovum carrying an X chromosome.Black button represents sperms carrying an X chromosome.Red button represents sperms carrying Y chromosome.

a) Place the white buttons in a petri dish. b) Put 25 red buttons and 25 black buttons in a black plastic.c) Shake the plastic bag and use your hand to mix the buttons inside. Without looking into the

bag and take out one button. Place it in the petri dish as diagram 2.d) Record the number of times the red of black button is taken out. Each time, put the red button

or black button into the bag.e) Repeats steps c) to d) for 49 times.

Diagram 2The result is recorded intable 2.

Combination of buttons Number of times Sex1 white button + 1red button 241 white button + 1 black button 26

Table 2

Based on the experiment which have been carried out, answer the following questions:

a) Determine the sex of the offspring by completing Table 2.

2m

b) Explain why a female only produces ova with X chromosomes.

2m


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c) Draw a schematic diagram to illustrate sex determination in offspring of humans.

3m

d) Which parent is responsible for determining sex of a child? Explain your answer.

3m

End of Question Paper

bengkel peperiksaan amali spm(1)

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