S Bio K3 Tspm09

MARKING SCHEME BIOLOGY 3 (4551/3) SPM TRIAL EXAMINATION

2009

Question1 1 (a)(i) (ii) KB0603 – Measuring Using Numbers Scor e 3

Explanation Able to record 1 reading for the initial mass and all 4 readings for the final mass of potato strips correctly . Sample Answer: Initial mass : 50 gm

1

Type of solution Final mass of potato strip after 30 minutes ( gm)

0.2M 58 0.4M 52 0.6M 46 0.8M 42

1

2

Able to record 1 reading for the initial mass and all 3 readings for the final mass of potato strips correctly .

1

Able to record any 1 reading for the initial mass and all 2 readings for the final mass of potato strips correctly .

0

No response or 1 reading for the initial mass and 1 reading for the final mass .

(b) (i) [KB0601 - Observation] 2

Scor e

Explanation Able to state two correct observations based on the following criteria : [Observation must have values for MV and RV from Table 1 or comparison between two readings.] MV : Concentration of sucrose solution RV : The final mass of potato strip

3

Sample answer: 1. In 0.2M sucrose solution, the final mass of potato strip is 58 gm. 2. The final mass of potato strip immersed in 0.8M sucrose solution is 42 gm. 3. The final mass of potato strip immersed in 0.8M sucrose solution is less than the final mass of potato strip immersed in 0.2M sucrose solution // inversely Able to state two different observations inaccurately OR without values.

2

Sample Answer: 1. At concentration 0.8 M, the final mass is the lowest // inversely. 2. The highest concentration of sucrose solution, the final mass is 58 gm // inversely. 3. The concentration of sucrose solution influences the final mass of potato strip . Able to state two different observations at idea level.

1

0

Sample Answer: 1. The concentration changes / increases / decreases. 2. The final mass of potato strip changes /increases /decreases. No response or wrong response. Scoring

3

Scor e Corre ct Inacc urate Idea Wron g 3 2 2 1 1 -

2 -

1 1 1 -

2 -

4

1 (b) (ii) [KB0604 – Making inference] Scor e

Explanation Able to state two inferences for each observation made correctly and accurately for each observation and equivalent in 1(b)(i).

3

Sample answers: 1. (At concentration of 0.2M), water molecule diffuse into the cell. 2. (At concentration of 0.8M), water molecule diffuse out of the cell. 3. More water molecule diffuse out of the cell at 0.8M but more water diffuse into the cell at 0.2M. Able to state any two inferences inaccurately .

2

Sample answers: 1. More water molecule diffuse . 2. The diffusion of water is influenced by concentration Able to state two inferences at idea level.

1

Sample Answer: 1. Osmosis occurs.

0

No response OR wrong response. Scoring:

5

Score Correct Inaccurat e Idea Wrong 3 2 2 1 1 -

2 -

1 1 1 -

2 -

1 1

6

1 (c) [KB0610 – Controlling Variables] Scor e 3

Explanation Able to state all 3 variables and the methods to handle the variable correctly. Sample Answer :

7

Variables Method to handle the variable correctly Manipulated variable: Concentration of sucrose solution Use 0.2M,0.4M,0.6M and 0.8M / different concentration of sucrose solution Responding variable : Final mass of potato strip // percentage change in mass of potato strip Using a triple beam balance measure and record the final mass of potato strip // Calculate the percentage change in mass of potato using formula: Final mass-Initial mass X 100% Initial mass

Constant variable: 1. Duration of immersion / 2. Length / mass of the potato strip / Volume of sucrose solution 1. Fix the time of 30

minutes to immersed the potato strip. 2. Used the length of 5mm / Fix the mass at 50 gm.

8

Able to state 4-5 correctly.

2

Able to state 2-3 correctly

1

No response or only one criteria correct.

0

1 (d) [KB0611 – Making Hypothesis] Scor e

Explanation Able to state a hypothesis by relating the manipulated variable and responding variable correctly with following aspects: P1 : Stating manipulated variable. P2: Stating responding variable H : Showing a specific relationship/ showing direction of relationship

3

Sample Answer : 1. As the concentration of sucrose solution increases, the final mass of potato strip decreases // the percentage change in mass decreases. 2. As the concentration of sucrose solution increases / decreases, the final mass of potato strip increases /decreases // the percentage change in mass increases // decreases Able to state a hypothesis relating the manipulated variable inaccurately.

2

Sample Answer: 1. The increase of the concentration of sucrose solution influences / affects the final mass of potato strip. 2. The percentage change in mass of potato strip is affected by concentration of sucrose solution. Able to state a hypothesis relating the manipulated variable at idea level.

1

0

Sample Answer : 1. Final mass of potato strip / concentration of sucrose solution changes. 2. As the final mass of potato strip increases the percentage change increases. No response or wrong response if no P1 or P2 no mark for each. 9

1 (e) (i) [KB0606 – Communication] Scor e 3

Explanation Able to construct a table correctly with the following aspects: 1 : Able to state the 4 titles with units correctly. 2 : Able to record all the data correctly. 3 : Able to calculate and record percentage change correctly Sample answer :

10

Concentration of sucrose solution (M) Initial mass (gm) Final mass (gm) Percentage change in mass Final mass-Initial mass X 100 Initial mass (%) 0.2 50 58 16.0 0.4 50 52 4.0 0.6 50 46 -8.0 0.8 50 42 -16.0

11

2 1 0

Any two aspects correct Any one aspect correct No response or wrong response.

1 (e)(ii) [KB0612 – Relationship between space and time] Scor e

Explanation Able to draw the graph correctly with the following aspects: P(paksi)

3

2 1

: Corrected title with unit on both horizontal, vertical axis and uniform scale on the axis. T(titik) : All points plotted / transferred correctly. B(bentuk) : Able to join the points to form a smooth graph / line Able to state any two correct. Able to state any one correct No response or wrong response.

0

1 (f) [KB0608 – Interpreting Data] 12

Scor e

Explanation Able to interpret data correctly and explain with the following aspects : Relationship : P1 = Able to state the concentration of sucrose solution which is isotonic to the cell sap

3

Explanation P2 = K Linmacam tak lengkap aje……………………………….. P3 = Able to state Sample answer : Produced (P3). Able to interpret data with two aspects correctly.

2 Able to interpret data only one aspect correctly. 1 No response or wrong response. 0 1 (g) [KB0609 –Defining by Operation ] Scor e

Explanation Able to define operationally based on the result of the experiment with the following aspects: P1 : Movement of water in / out P2 : Plasma membrane of the potato cells P3 : Difference in concentration gradient between the sucrose solution and the cell sap.

3 Sample answer: 1. Osmosis is a process in which water molecules entering / leaving the potato strips (P1) across the plasma membrane of the potato strip (P2) when there is a difference in concentration gradient between the sucrose solution and the cell sap (P3). 2

Able to define operationally based on the result of the experiment with two aspects correctly. 13

1 0

Able to define operationally based on the result of the experiment with only one aspects correctly. No response or wrong response

1 (h) [KB0605 – Predicting] Scor e

Explanation Able to predict and explain the outcome of the experiment correctly with the following aspects: Prediction : P1 : Able to predict the mass of the potato strip correctly.

3

Explanation : P2 : Able to state distilled water is hypotonic P3 : Able to state more water molecules diffuse into the potato strip Sample answer: 1. The mass of the potato strip increases more than 46 gm // any values more than 46 gm .Water molecules diffused into the potato strip because distilled water is hypotonic. ** P1 must be correct to get P2 & P3, if P1 wrong automatically reject P2 & P3 - for score 3, 2, 1

2 1

Able to predict and explain the outcome of the experiment correctly with the two aspects . Able to predict and explain the outcome of the experiment correctly with one aspect correctly. No response or wrong response.

0

1(i) [KB0602 – Classifying] Able to classify all 3 solutions concentration and types of solution 14

correctly: Solution concentrations Kepekatan larutan (%) Types of solution compared to the osmotic concentration of cell sap Jenis larutan dibandingkan dengan kepekatan osmotik sap sel 0.25% natrium chloride solution Hypotonic 3

0.8% natrium chloride solution Isotonic

1.10% natrium chloride solution. Hypertonic

2

Able to classify 2 solutions concentration and types of solution correctly 15

Able to classify 1 solution concentration and types of solution correctly 1 No response or wrong response

0

Question 2

KB061201 – ( Problem statement) Score

Criteria Able to state the problem statement correctly : C1 : Manipulated variable C2 : Responding variable R : Question form and have relationship

3 Sample Answer : 1. How does air movement affect the rate of transpiration ? 2. How does ( wind) affect the rate of transpiration ? ** Without question mark (?) – score 2 2

Able to give a statement of identified problem but incomplete. 16

Sample Answer: 1. Does air movement have a relationship with the rate of transpiration ? 2. Does wind have a relationship with the rate of transpiration ?

Able to give idea of a statement of identified problem.

1

Sample Answer: 1. What is the effect of air movement / wind?

0

No response or wrong response

KB061202( Making Hypothesis )

Score 3

Criteria Able to state the hypothesis correctly by relating two variables. Criteria set:

C1 : State the manipulated variable C2 : State the responding variable R : Show the specific relationship and direction between the manipulated variable and the responding variable. Answer must have C1, C2 and R 17

Sample Answer :

1. The higher the air movement , the higher the rate of transpiration. 2. The higher the wind , the higher the rate of transpiration

Able to make a statement of hypothesis which relates the manipulated variable to the responding variable.

Answer must have C1 and C2 but without correct relationship 2 Sample Answer : 1. The air movement affect the rate of transpiration 2. The wind affect the rate of transpiration Able to state an idea of a statement of hypothesis.

1

Sample Answer: 1. The air movement / wind increases.

0

No response or wrong response

KB061203 - Planning ( Planning for investigation) 18

Score 3

Criteria Scoring Criteria : Able to state 7- 9 planning investigation of experiment following :

• •

Problem statement (PS) – idea Aim of investigation / Objective (Ob) – Relation between C1 and C2 Sample answer

1. To investigate the effect of air movement / wind on the rate of transpiration.

• •

Statement of hypothesis (Hp) – idea States variables – (Vr) All three variables must be correct :

Manipulated variable : Moving air / wind Responding Variable : Time taken by the air bubble to move a distance of 2 cm. Constant Variable :

Temperature / Relative humidity / light intensity

• •

List of materials and apparatus (AM) Technique (Tq) – Correctly and accurately Bonus 1/B1 = 1 mark

Sample Answer:

19

Record the time taken for the bubble to move a distance of 2 cm using a stopwatch.

• •

Procedure / Method of investigation (K)– must have at least one criteria either K1 / K2 / K3 /K4 /K5 Data presentation // presentation of result (RD) – Have table with 3 titles with correct units and no data is required

Sample Answer :

20

External condition Time taken for the air bubble to move a distance of 2 cm (seconds) Rate of transpiration (mms-1)

1 2 3 Average

Using the fan / air movement ( wind)

Without fan / no air movement

21

2

1 0

Scoring Criteria : State 4 - 6 items Scoring Criteria: State 1 - 3 items No response or wrong response

KB061204 ( Method / procedure of investigation) Score

Criteria Able to state all five criteria K1,K2, K3, K4 and K5 :

Criteria : 3

K1 : Preparation of materials & apparatus (any 5) - Cut a leafy balsam / named plant shoot - The capillary tube and rubber tubing are filled with water. - The leafy shoot is inserted into the rubber tubing under water. - The capillary tube is lifted up above the water surface to trap an air bubble. - The capillary tube is placed back into the beaker of water and kept upright using a retort stand. - A fan is used to create condition air movement . - Steps 5-9 is repeated twice to obtained an average reading. - The experiment is repeated without using the fan . - The results are recorded in a table. 22

- The rate of transpiration is calculated. Remark : Able to state any five (K) steps to get P1.

K2 : Operating Fixed variable - The potometer is placed at room temperature ,37 oC

K3 : Operating responding variable - Record the time taken by the air bubble to move a distance of 2 cm using a stopwatch

K4 : Operating manipulated variable -

Repeat the experiment without using fan.

K5 : Precaution / Accuracy of experiment (Any 1) State one precaution steps in the experiment. Sample Answer: - Cut a leafy balsam / named plant shoot slantly under water - The leaves are wiped dry . - Some vaseline Is smeared around the rubber tubing

Sample Answer:

Method / Procedure : 23

1. Cut a leafy balsam / named plant shoot slantly under water to prevent air from entering the xylem. 1. The capillary tube and rubber tubing are filled with water. 2. The leafy shoot is inserted into the rubber tubing under water. 3. The leaves are wiped dry. Some vaseline is smeared around the rubber tubing to make the apparatus airtight. 4. The potometer is placed in a beaker of water for 5 minutes at room temperature to allow water to move up the capillary tube. 5. The capillary tube is lifted up above the water surface to trap an air bubble. 6. The capillary tube is placed back into the beaker of water and kept upright using a retort stand. 7. Mark two points , P and Q at a distance of 2 cm apart on the capillary tube. 8. A fan is used to give air movement. 9. A stopwatch is activated and the distance travel by the air bubble from P to Q point is recorded. 10. Steps 5-9 is repeated twice to obtained an average reading. 11. The experiment is repeated without using fan. 12. The results are recorded in a table. 13. The rate of transpiration is calculated. 2

Able to state 4 criteria

1

Able to state 2-3 criteria

0

No response or wrong response

KB061205 (Listing of Materials and Apparatus)

Skor 3

Perkara Abble to state all the materials and apparatus: Sample Answer:

24

Materials : *Leafy balsam shoot, *distilled water vaselin

Apparatus : *capillary tube,* rubber tubing, beaker,*stopwatch,*fan marker pen/thread, tissue paper/cloth , retort stand

2

Able to state two of the * materials and four * apparatus

1

Able to state two of the * materials and two *apparatus including

0

No response or wrong response

Mark: 3X5

= 15 marks

B1 = 1 mark( technique) B2 = 1 mark( Data presentation) TOTAL = 17 marks

END OF MARKNG SCHEME 25

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