~ Science Practice Paper 2 ~

31a) When the water was heated, the hot water vapour came into contact with the cooler surface of the funnel, lost heat (1M) and condensed (1M), thus forming water droplets on the underside of the cover.



b) The liquid is colourless and tasteless.
(Don't be tricked !!!

Water vapour condenses to form the water droplets!

The liquid will not be coloured, if not your water vapour in the air would already be coloured too!

Also, salt is solid, it will not evaporate! Only the water! Salt will be left behind in the beaker!)



32) 

33a) He should change only one variable / physical condition for each seed.

b) Seed R

c) Germination of seeds does not require mineral salts, so there is no need for soil to be used.






34a) The seeds are dispersed by animals which ate the fruit.

b) The small, hard seeds are swallowed by the animals, but are undigested (1M). They are dispersed when the animals passed out the seeds (1M).    *See! Got to be very detailed!* 





35a) Blood vessel P. Blood from the heart going to the lungs has the least amount of oxygen as oxygen is used by the other parts of the body.

*READ the question properly!

They asked for WHICH BLOOD VESSEL and you are given blood vessels P, Q, R & S!

Do not give me other answers like A, B, C, D, veins, capillaries, arteries...etc.*



b) It is to supply digested food and oxygen quickly to other parts of the body to release more energy. 

*Many of you will miss out the 2nd part! Important! Must talk about ENERGY always!*





36a) The water is used by the leaves for photosynthesis / to make food.

b) Water moves in one way in plants while blood circulates throughout the human body.




37a) T
b) F Blood carries digested food, YES. But now the question is only asking about RED BLOOD CELL. It only carries oxygen!
c) T
d) F




38a) The bulbs in both circuits are arranged in series, that is why the brightness of the bulbs are the same in both circuits.

b)

39a) Ali was investigating the flexibility of materials / if the materials are flexible or not.

b) Thickness / length of material.



40a) She should bring each electromagnet close to some paper clips / pins/ staples. (0.5M)

        She should count the number of paper clips / pins / staples attracted by each electromagnet. ( 0.5M)

        The more pins attracted, the stronger the electro magnet. (1M)


b) Use different number of batteries for each iron nail but same number of coils around each iron nail.





41a) Group A: Plants
        Group B: Fungi

b) He is wrong. Moss is a non-flowering plant not fungi. It can make its own food. *Elaborate! Explain!*





42a) Translucent / Frosted

b) As the thickness of Material Z increases, the amount of light passing through it decreases.

c) The experiment will not be accurate if other light sources are captured by the light sensor.



43a) As the flask was heated, the air in it gained heat and expanded causing it to be forced out of the glass tubing and into the coloured water as air bubbles.

b) The water would move up the glass tubing.

c) The air in the flask cools down and contracts (0.5M). The water in the beaker then moves up to take up the space previously occupied by air.



44a) This is to ensure that the reading is consistent and more reliable.

b) In Flask B, air was able to escape through the outlet (0.5M) of the flask. This enabled water to enter to occupy its space (0.5M).

c) Remove the cork from the mouth of the flask and lift the funnel above the flask.