answering technique biology paper 3

BIOLOGYBIOLOGYSPMSPM

SPM FORMATSPM FORMAT

Paper 1 = 50 objectives = 50 marks

Paper 2 = 5 structures + = 100 marks

2 essays

Paper 3 = 1 structure + = 50 marks

1 exp. report

TOTAL =200/2

THINK THIS WAY…THINK THIS WAY…

Paper 1 =50 marksUsually my mark is.. =25 marksPaper 3 =50 marksI can get about.. =25 marksTotal mark for 2 papers =50/2 papers

=25 markah…=Can Pas laa….

Paper 2?

Paper 3 Paper 3

Question 1(Structered practical item)

-33 marks

Question 2(Open-response item)

-17 marks

Paper 3 SPM 20091(a) Record readings

Distance from the bulb (cm)

Length of gas bubble (cm)

50 1

40 2

30 3

20 4

10 5

5 ticks=3m, 3-4 ticks=2m, 1-2 ticks=1m

(b) (i) Observations(b) (i) Observations

1. At a distance of 10cm from the bulb, the length of gas bubble is 5cm.

2. At a distance of 50cm from the bulb, the length of gas bubble is 1cm. (3 marks)

Inaccurate example:1. At a distance of 10cm from the bulb, the length

of gas bubble is long.2. At a distance of 50cm from the bulb, the length

of gas bubble is short. (2 marks)

(b) (ii) Making inference(b) (ii) Making inference

1. High light intensity, more gas to be produced/ high rate of photosynthesis.

2. Low light intensity, less gas to be produced/ low rate of photosynthesis.

(3 marks)

Inaccurate example:1. High rate of photosynthesis.2. Low rate of photosynthesis.

(2 marks)

(c) Variables Method to handle the variable

Manipulated:

*Distance between the light source and plant

*Light intensity

*place the bulb at different distance from the plant/ 10cm,20cm…50cm

*different light intensity

Responding:

*The length of gas bubble

*The rate of photosynthesis

*use ruler to measure and record the length of gas bubble

*calculate the rate of photosynthesis using the formula:

Length of gas bubble (cm)/time (min)

Constant:

*Type of plant

*Percentage of sodium hydrogen carbonate

*Use the same type of plant,which is aquatic plant

*Use the same percentage of sodium hydrogen carbonate

6 ticks=3m, 4-5 ticks=2m, 2-3 ticks=1m

(d) Hypothesis(d) Hypothesis

• Manipulated + responding + relationship

Example :

As the light intensity increase, the rate of photosynthesis increase

As the distance from the bulb increase, the length of gas bubble decrease

(3 marks)

Inaccurate example:As the light intensity increase, the photosynthesis

increase

The length of gas bubble depends on the distance from the bubble

(2 marks)

*Never use….AFFECT, INFLUENCE, DEPENDS...

(e) (i) Construct a table(e) (i) Construct a table

Titles (with units) + Data + Calculations

Distance from the bulb (cm)

Length of gas bubble (cm)

Rate of photo

(cm/min) or

(cm/s)

10 5 1.0 or 0/01671

20 4 0.8 or 0.01331

30 3 0.6 or 0.010

40 2 0.4 or 0.0067

50 1 0.2 or 0.003

(e) (ii) Draw graph(e) (ii) Draw graph

P (axis) - uniform scales on both horizontal and vertical axis

T (points) - all points plotted correctly

B (shape) - able to join all the points to form a smooth graph

(f) Interpretating data(f) Interpretating dataRelationship + Explanation

• As the distance increases, the rate of photosynthesis decreases because the light intensity decreases and less gas is produced (3marks)

Many student only answer…As the distance increases, the rate of

photosynthesis decreases (1mark)

(g) Defining by operation (g) Defining by operation

Photosynthesis is the process that takes place in an aquatic plant. It requires light from the bulb, sodium hydrogen carbonate and produces gas bubbles. The rate of photosynthesis is influenced by the light intensity.

(3 marks)

Students answer…

(h) Predicting(h) Predicting

Prediction + Effect + Reason

The length of gas bubbles increases more than 3 cm, because the concentration of sodium hydrogen carbonate solution increases, more gas is produced

( 3 marks)

Most students only answer the Prediction !!!

( 1 mark only)

(i) Classify(i) Classify

Requirements Products

Water Glucose

Carbon dioxide Oxygen

Chlorophyll

Light

6 ticks=3m, 5 ticks=2m, 4 ticks=1m

2. Report Writing2. Report Writing

Aim:

To study the effect of temperature on the rate of enzyme reaction

Problem Statement:*What are the effect of temperature on the

rate of enzyme reaction?

*What are the effect of temperature on amylase activity on starch?

Hypothesis:When the temperature increase, the rate of enzyme

reaction increase (until optimum temperature) orWhen the temperature increase, the rate of enzyme

reaction decrease

Variables:Manipulated :temperature Responding :the rate of enzyme reaction or

time taken for the hydrolysis of starch

Fixed :volume of amylase / volume of starch..BUT LIST 1 ONLY!!

Apparatus:Beaker, test tube, thermometer, measuring

cylinder, stopwatch, bunsen burner, tripod stand, wire gauze

Materials:

Starch, amylase, water, ice cube, iodine solution *

Technique:#

Using a stopwatch to record time taken for complete hydrolysis of starch/iodine to change colour

Procedure:1. Use syringe to put 5ml of 1% starch

suspension into each of the test tubes, labelled A1, B1, C1, D1 and E1

2. Use a second syringe to put 2ml of saliva (amylase) into each of the test tubes, labelled A2, B2, C2, D2 and E2

3. Immerse A1 and A2 into water bath with temperature at 10 0 C cold water.

4. Mix test tube A1 into A2

5. Start the stopwatch.6. Use a dropper to put a drop of mixture

test A2 onto the iodine solution in the first groove of the white tile.

7. Repeat the iodine test for every 10 minutes.

8. Rinse the dropper after each sampling.9. Record the time taken for the complete

hydrolysis of starch in a table.10.Repeat the experiment with temperature

of 200C, 300C,400C and 500C .11.Record all result in a table.

Result:#

Temperature (oC) Time taken for the starch to disappear (min)

Rate of reaction (min -1)

10

20

30

40

50

Conclusion:When the temperature increase, the rate of

enzyme reaction increase (until optimum temperature) or

When the temperature increase, the rate of enzyme reaction decrease

Experiment Planning-all correct (9 steps) 5 x 3 = 15 marks# Bonus 1 mark for each technique and correct

result table

Total = 17 marks

SEMOGA BERJAYA