A decrease in the amount of algae will cause an increase in the number of all the organisms.

An increase in the population of big fishes is likely to cause an increase in the population of frogs.

An increase in the number of water bugs is likely to cause a decrease in the number of small fishes.

(1)    A decrease in the population of tadpoles is likely to cause a decrease in the population of water bugs.

body covering

The way they breathe

The way the reproduce

The number of stages in their life cycles

The chicks are most likely to survive at higher temperatures.

They do not hatch when incubated at temperatures lower than 20 ^oC.

They are more likely to hatch when incubated at higher temperatures.

The number of eggs that hatch affect the temperature of the incubators.

Respiration begins.

Photosynthesis stops.

Respiration rate is at its maximum.

Photosynthesis rate is at its maximum.

Do the leaves of a plant absorb water?

Do plants need roots to absorb water?

Does the stem help to transport water to the leaves?

Does the number of leaves affect how fast water travels up the stem?

1

2

3

4

 A and B only

 A and C only

B and D only

 A, C and D only

The water is more polluted at Point B than at Point A.

The factory pollutes the river water more than the farm.

The water at Point A is more polluted than the water at Point C.

 Only the organisms at Point C will be affected by the effects of pollution.

Seed W

Seed X

Seed Y

Seed Z

P

Q

R

S