Bengkel Krk2

SEKOLAH MENENGAH KEB KING EDWARD VII JALAN MUZIUM HULU 34000 TAIPING PERBENGKELAN SAINS KRK 2007 1. Diagram 1 shows the structures of the human skin.

Pain receptor

Touch receptor Pressure receptor

DIAGRAM 1 (a) On Diagram 1, label the structures R, P and S. [3 marks] (b) Name the system in Diagram 1. Nervous system……………………………….. [1 mark] (c) State two functions of the organ in Diagram 1. Regulate the body temperature……………………… Respond to surrounding…………………………any answers……………… [2 marks]

2. Diagram 2.1 and Diagram 2.2 shows the visions of an animal and a human.

Stereoscopic vision DIAGRAM 2.1

monocular vision DIAGRAM 2.2

(a) In the spaces provided on Diagram 2.1 and Diagram 2.2 name the type of visions. [2 marks] (b) State the advantage of the vision in Diagram 2.1. Can see a large area

[1 mark]

( c) State 2 characteristics of the vision in Diagram 2.2. Used both the eyes……………………………….. Have eyes in the front of head………………………………………………. [2 marks] (d) List two examples of animals with the vision of Diagram 2.1 Horse and Rabbit ……………….

any answers [2 marks]

3. Diagram 3 shows a human digestive system.

liver

stomach

Gall bladder

pancreas Small intestine

appendix

Large intestine DIAGRAM 3

(a) Name the parts labelled P, Q, R, S, T, U and V. [2 marks] (b) What is produced by part U? bile…………………………….

[1 mark]

( c) Which part does digestion ends? Small intestine [1 mark] (d) State the enzymes excreted in Q lipase………………………………………………. amylase………………………………………………………. pepsin………………………………………………………. [3 marks]

4. Diagram 4 shows an experiment on the electrolysis of water.

DIAGRAM 4 (a) Name two elements of water Hydrogen and Oxygen

[2 marks]

(b) Define electrolysis. [2 marks] Process of splitting/decomposing water into hydrogen and oxygen by using electrical energy ( c) Based on the above diagram, (i) what is gas Y? [1 mark] oxygen (ii) What will happen when gas X is tested with a burning wooden splinter? [1 mark] “pop” sound will be heard (iii) What is the ratio of volume of gas X and Y collected at cathode and anode? 2:1 [1 mark]

5.

DIAGRAM 5 The above diagram shows a graph of solubility of solutes P, Q and R against temperature. (a) What is solubility? [2marks] 3 Number of grams of the solute that can dissolve in 100 cm of water at a certain temperature to form a saturated solution (b) Based on the above graph, (i) what happens at point S? [1 mark] Same amount of solute dissolved at the same temperature (ii) which solute has the lowest solubility at 15oC? [1 mark] Solute Q (iii) which solute has the highest solubility at 75oC? [1 mark] Solute P (c) Give two factors beside temperature that affect the rate of dissolving a solute in a solvent? i Nature of solute

-ii—Amount of solvent

---------------------------------------------------------------[2 marks]

6. (a)

DIAGRAM 6 The above diagram shows some water is boiled in a metal tin. The tin is then sealed immediately and placed under cold running water. (i)

What will happen to the metal tin? Dented (ii) Explain your answer in (a). Air pressure in the tin is reduced (iii) Give two applications of air pressure in our daily life. Insecticide spray and straw ……..any answers

[1 mark] [1 marks] [2 marks]

(b)

(i)

Based on the above diagram, what will happen to the balloon when air is pumped out of the bottle? [1 mark]

Expand (ii) Explain your answer in (a). [2 marks] Air pressure in the balloon is increase (iii) Beside temperature, what will affect the air pressure in a covered container? [2 marks] Volume of container and amount of gas

( c)

Gases are usually stored in the form of liquid in cylinders and aerosol cans.

Give two examples of gases stored in gas cylinders. [2 marks] Oxygen and Butane ……………any answers

7. (a)

(i) Define work done. [1 mark] Work is done when a force moves an object through a distance. (ii) A machine produces 15000 J of work in 30 seconds. Calculate the power produced by the machine. [3 marks] Power = work/second [ 1 mark] = 15000/30 [1 mark] = 500 W [1 mark]

(b)

A worker carries a box with a mass of 20 kg. He climbs up a flight of stairs of 30 steps in 10 seconds. Each step is 25 cm high. (i) Calculate the work done. [3 marks] Force 20 x 10 = 200N, 30 steps x 25cm = 7.5m. Work = f x d = 200 x 7.5 = 1500Joule (ii) Calculate the power produced by the worker. [3 marks] Power = Work/time = 1500/10 = 150 Watt

( c)

(i) Define power. [1 mark] Amount of work per unit time or Rate of doing work (ii) A man with a mass of 50 kg pushes a car with a mass of 1500 kg against the wall for 10 seconds. Calculate the work done. [1 mark] No work is done. Work is zero

8. (a)

Study the animal in the below figure.

(i) Explain how this animal supports its body weight. [1 mark] Endoskeleton (ii) Land vertebrates like deer have hollow bones. Why? [1 mark] Very strong (b)

(i) State one similarity between land vertebrates and aquatic vertebrates. [1 mark] Have backbone (ii) How is the body weight of aquatic vertebrates being supported? [1 mark] Buoyancy or up thrust of water (iii) What will happen if a whale is washed ashore? Explain. [2 marks] Cannot support its own weight, because the whale has very small and weak pectoral and pelvic girdles. [ cannot move]

( c)

Study the cross-section of the stem of a plant in the below figure.

(i)

(i) Where does this plant grow? [1 mark] In water (ii) Explain your answer in (a)(i). [1 mark] It has air sac / air space (ii) What happen if the part labelled with X is removed? [1 mark] Sink in water

(iii) State two plants that have the same stem structure. [2 marks] Water lily and lotus 9. (a).

(i) State what a lever consists of. [1 mark] Long stick, with effort, fulcrum and load (ii) List all classes of lever and give an example for each of them. [3 mark] First class lever = hammer any answers Second class lever = wheel barrow any answers Third class lever = fishing rod any answers (iii)

State the class of lever the above object belongs to. [1 mark] Second class lever (b)

(i) Define moment of force. [2 marks] Turning effect of a force, or force x perpendicular distance of the force from the point. (ii) State two factors that affect the moment of force. [2 marks] Force and distance

(c)

The two children in the above diagram sit at an equal distance from the fulcrum.

(i) State the class of lever of the above object. [1 mark] First class lever (ii) Calculate the distance that the girl has to sit to make the seesaw balanced. 3 marks] Clockwise moments = anticlockwise moments = 2m x 600N = m x 300N = 4m

10. Diagram 10 shows an experiment to test the presence of starch in green leaf. [Pot of plant which has been kept in the day after few hours is tested for presence of starch.]

A B

C

D

E Blueblack

DIAGRAM 10 (a) Based on your observation, what inference can be made.

-Green leaf make starch in the presence of light---------------------------------- [1 mark]

(b) State the variables involved in this experiment. Constant variable Manipulated variable Responding variable

Type of leaf Present of light Presence of starch [3 marks]

( c) State the purpose of each stages Stage A Stage B Stage C Stage D Stage E [5 marks]

Boil the leaf in water to break the cell walls Boil the leaf in alcohol to remove its chlorophyll Soak the leaf in hot water to soften the leaf Put a drop of iodine to test the presence of starch Starch is present

(d) Define photosynthesis. Photosynthesis is the process in which green plants make food in sunlight using water and carbon dioxide [ 2 marks] (e) Write the equation for photosynthesis. Carbon dioxide + water [ sunlight & chlophyll]

------- Starch + oxygen [1 mark]

11. Diagram 11 shows 8 animals, based on your observation, state one characteristic of each animal

P Q R S PT U V W

Has legs Has legs Has legs Has legs Has legs Q Has segments Has soft body Has shell

U

R

S

T

V W [8 marks]

(B) Classify them into 2 group based on their common characteristics

P,Q,R,S,T,U,V,W Common characteristics

Has Legs

Cockroach Beetle Spider Scorpion Millipede

Without Legs

Name of animals

Slug Snail Earthworm [4 marks]