Sains K2 Trial Spm Pahang 2008 (ans)

PERATURAN PEMARKAHAN PENILAIAN BERSAMA PERCUBAAN SPM (SAINS) 2008 PAHANG

QUE

ANSWERS

Mar

∑ Mar

SECTION A 1(a)

Able to draw the graph of the volume of gas against time correctly Answer 1. Transfer of all points correct - 1 mark 2. Smoothness of the curve - 1 mark

2

2

(b)

Able to state the relationship between the volume of gas Z and time correctly Sample answer

1

1

1

1

1

1

1. When the time increases the volume also increases (c)

Able to state the responding variable correctly Sample answer 1. The volume of gas

(d)

Able to write the volume of gas Z at the fifth minute correctly Sample answer 1. According to the graph drown by the candidates. 2. No mark will be awarded if no graph is drawn.

Total

5

2 (a)

Able to measure the focal distance of lens B correctly Answer

1

1

1

1

1

1

1

1

1

1

Total

-----5 ===

1. 6.2 cm. (+ and - 0.2) or 2. The actual length as on the question paper (b)

Able to predict the focal distance of a convex lens which is thinner than lens B correctly Sample answer 1. The length must be longer than 6.4 cm 2. The answer depend on the size of the diagram on question paper

(c)(i)

Able to state the manipulated variable correctly Sample answer 1. The size of the lens 2. The thickness of the lens

(c)(ii)

Able to state the responding variable correctly Sample answer 1. The focal length 2. The image distance

(d)

Able to show the relationship between manipulated variable and the responding variable for the experiment correctly Sample answer 1. The thinner the thickness of convex lens the focal distance is longer 2. Thicker convex lens have shorter focal length 3. Thinner convex lens have longer focal distance

3 (a)

Able to state is the weight of the plasticine in the air accurately Answer

1

1

1

1

1

1

1

1

1

1

Total

5 ===

1. 14 (N) (b)

Able to state one observation of the experiment correctly Sample answer 1. The weight of plasticine decrease in the water compared to the air 2. Plasticine more lighter in water than air 3. Plasticine heavier in air than water

(c)

Able to write one inference based on the observation correctly Sample answer 1. The present of upthrust force 2. The present of buoyant force

(d)

Able to state the constant variable correctly Sample answer 1. Size of plasticine 2. Mass of the plasticine

(e)

Able to predict the weight of plasticine in sea water correctly Sample answer 1. more lighter 2. less than 6N 3. < 6N

4(a)(i)

Able to state the manipulated variable correctly Sample answer

1

1

1

1

1

1

1

1

1

1

Total

5

1. Type of plastic (a)(ii)

Able to state the responding variable correctly Sample answer 1. The hardness of the plastic

(b)

Able to show the relationship between manipulated variable and the responding variable for the experiment correctly Sample answer 1. Thermoplastic is softer than thermosett 2. Thermosett is harder than thermoplastic

(c)

Able to state the operational definition for the thermoplastics correctly Sample answer 1. Thermoplastic is a plastic that become soft when heated. 2. Thermoplastic is a plastic that become soft when put under higher temperature.

(d)

Able to tick the objects which are made from thermoplastic correctly. Sample answer 1. The candidate must tick under Telephone and Electric plug 2. Both answers must be correct. 3. One answer is not acceptable.

SECTION B 5(a)(i)

Able to name structure P in Diagram 5 accurately Answer

1

P: Sensory neurone (a)(ii)

Able to state the function of structure P accurately Answer

1

2

1. To transmit impulse to the brain (b)(i)

Able to name the receptor that involve in this system correctly Sample answer

1

1. Stretch receptor 2. Proprioceptor (b)(ii)

Able to state the function of receptor correctly Sample answer

1

2

1

1

1

1

Total

6

1. To detect any slight movement in the body 2. To detect any contraction of the muscle (c)

Able to state example of daily activities that involve in the system correctly Sample answer 1. Buttoning shirt without looking 2. Riding bicycles without looking at the pedals 3. Typing text using a computer without looking at the keyboard.

(d)

Able to state the importance of the system to human correctly Sample answer

1. To maintain balanced coordination of the body

6(a)

Able to name the gametes P and Q accurately Answer

2

2

P: Sperms Q: Ovum (b)

(c)

Able to name the process X and Y accurately Answer Process X:

Fertilization

1

Process Y:

Mitosis

1

2

1

1

1

1

Total

6

Able to name cell M accurately Answer Zygote

(d)

Able to state the type of twin formed accurately Answer Identical twin

7(a)

Able to name the process shown in Diagram 7 correctly Sample answer 1. 2.

(b)

(c)(i)

1

1

2

2

Radioactive decay Nuclear fission

Able to state the radioactive radiations labelled S and T accurately Answer S:

Gamma rays

T:

Alfa rays

Able to identify the negatively charged radiation accurately Answer

1

1. R 2. Beta (rays)

(c)(ii)

1

2

1

1

Total

6

Able to name the product other than radiation correctly Sample answer 1. Heat 2. Energy

(d)

Able to state one uses of radioactive radiation in medicine correctly Sample answer 1. To kill cancerous cells in radiotherapy 2. To sterilise medical equipment 3. To diagnose / cure certain diseases

8(a)(i)

Able to name the type of immunity acquired by the patient correctly Sample answer

1

1. The passive artificial immunity 2. The passive immunity (a)(ii)

Able to name the substance injected to the patient accurately Answer

1

2

1

1

1

1

1

1

1

1

Total

6

Antiserum (b)

Able to state correctly the source of immunity acquired naturally. Sample answer 1. From mother to the foetus during pregnancy 2. From mother’s milk

(c)

Able to name the immunity represented by the graph in Diagram 8.2 correctly Sample answer 1. Active artificial immunity 2. Vaccine 3. Active immunity

(d)

Able to explain the purpose of the second injection of vaccine correctly Sample answer 1. To increase the level of antibodies in the blood beyond the immunity level. 2. To boosts the production of antibodies in the blood.

(e)

Able to state the happening in the body after vaccination correctly Sample answer 1. The white blood cells are stimulated to produce antibodies 2. The lymphocytes are stimulated to produce more antibodies

9(a)(i)

Able to identify substance R correctly Answer

1

Ammonium compounds (a)(ii)

Able to state the form of nitrates that can be absorbed by the plants correctly. Sample answer

1

2

2

2

1

1

1

1

Total

6

1. Solution 2. ionic form

(b)

Able to name the types of bacteria involved in processes P and Q accurately Answer P: Nitrogen fixing bacteria Q: Denitrifying bacteria

(c)

Able to name the plant involved in process P correctly Sample answer 1. 2. 3. 4.

(d)

Legume plant Groundnut Rhizobium Been plant

Able to state one example of chemical fertilizer which increases nitrates in soil correctly Sample answer 1. Ammonium nitrate

SECTION C 10(a)

Able to show the relationship between manipulated variable and the responding variable correctly Sample answer

1

1

1

1

2

2

1

1

1. Vulcanised rubber is more elastic than natural rubber 2. Vulcanised rubber is less elastic than natural rubber (b)(i)

Able to write the aim of the experiment correctly Sample answer 1. To investigate the elasticity of vulcanised and natural rubber. 2. To study the elasticity of vulcanised and natural rubber

(b)(ii)

Able to identify the variables correctly Sample answer Manipulated variable 1. type of rubber 2. vulcanised rubber and natural rubber Responding variable 1. The elasticity of the rubber 2. Ability to return to its former length after stretching 3. The length of the rubber after hanging with the weight Constant variable 1. 2. 3. 4.

(b)(iii)

Length of the rubber before stretching The mass of the weight / 500g weight Time The size of the rubber [Any two variable]

Able to list the functional apparatus and materials to be used in the experiment correctly Sample answer Vulcanised rubber, natural rubber, weight with a mass of 500g, string, 2 clips, a stop watch, a retort stand and meter ruler (length measuring instrument)

(b)(iv)

Able to write the procedure for the experiment correctly Sample answer

4

4

1

1

Total

10

1. Clip both end of the vulcanised rubber // Diagram 2. One clip is used to hang the vulcanised rubber to a retort stand and the clip at the other end is tied with 500 g weight 3. After 30 minutes take out both clip 4. Measure the length of the vulcanised rubber // record the length of the vulcanised rubber 5. Repeat procedure 1 to 4 for natural rubber [Any four procedure]

(b)(v)

Able to draw the table correctly Sample answer

Type of rubber

The elasticity of the rubber // The length of the rubber after hanging

Vulcanised rubber

Natural rubber

11(a)

Able to state explain four uses of ammonia in everyday life correctly Sample answer 1. 2. 3. 4. 5. 6. 7. 8.

To make paints and colouring agents To make synthetic fibres / nylon To make nitric acid to be used in industry To prevent latex from clotting in rubber industry To make cooling agent in air conditioner / refrigerator To make ammonia fertilisers used in agriculture To make trinitrotoluene / TNT use in rock explosion To make laundry detergent [Any four]

4

4

11(b)

Able to identify the information from Diagram 10 correctly Sample answer

1

1

2

2

1

1

1

1

1

1

Total

10

1. Stainless steel, bronze and brass are example of alloy. 2. Stainless steel is made up of iron and carbon, bronze is made up of copper and tin and brass is made up of copper and zinc. Able to identify the common characteristics of the alloy in Diagram 10 correctly Sample answer 1. The alloys are made up of two or more elements. 2. The foreign atom will stop the sliding of main atoms 3. The alloy is stronger than its pure metal / element 4. [Any two] Able to state other example of alloy correctly Sample answer 1. Pewter 2. Duralumin 3. Cupronickel Able to state non example of alloy and reasons correctly Sample answer 1. Any pure metal (eg. Tin, copper, zinc) 2. Plastic, wood etc. Reason: Its does not make from two or more metals. Able to state the actual concept of alloy correctly Sample answer 1. Alloy is a mixture of two or more elements / metals which is stronger than its pure metals or non metals

12(a)

Able to state four ways how the processed and packed food become spoilt, correctly Sample answer

1. 2. 3. 4. 5.

4

Won out package that allow the microorganism to enter the food Expiry date is over Food is not kept under correct temperature / proper place Contamination occur during packaging Food is not process according to standard [Any four]

(b)

Able to identify the aim of choice correctly Sample answer

1

1. To maintain the freshness of vegetables and fruit for several days Able to explain two methods of maintaining freshness of the vegetables and fruits correctly Sample answer

4

1. Cooling: Keep the fruit and vegetables under 0 oC to 10 oC 2. Vacuum packing: The process of preparing food by releasing all air from the food container. 3. Irradiation: Processing food by exposing to radioactive radiation. (Any two method and its explanations) Able to list the methods according to its priority correctly Sample answer 1. Cooling 2. Vacuum packing 3. Irradiation

1

4

Able to select the most suitable method and giving reason correctly Sample answer

1

6

Total

10

The most suitable method is COOLING because it can be done under 0 oC to 10 oC / in the cooling section of the regenerators.