Questions And Answers |best|: Psle 2012 Science

A ball is dropped from a height of 2 metres. It bounces back to 1 metre.

(a) Cell wall (or large vacuole or chloroplasts – but onion cells have no chloroplasts; cell wall is best). (b) Controls cell activities / contains genetic material.

Water from a pond dries up after a few hot days. psle 2012 science questions and answers

A pupil wants to test if light is needed for photosynthesis. She uses two potted plants, one in sunlight and one in a dark cupboard. After 48 hours, she tests both leaves for starch.

(a) What process do the plants carry out during the day that benefits the fish? (b) What gas do the fish release that is used by the plants? A ball is dropped from a height of 2 metres

(a) Refraction. (b) Light bends when it passes from water to air (different densities).

The life cycle of a mosquito: Egg → Larva → Pupa → Adult. (b) Controls cell activities / contains genetic material

(a) What is this rapid growth of algae called? (b) Explain how this affects fish in the river.