a.

I and II only

b.

I, II and IV only

c.

I, III and IV only

d.

I, II, III and IV

a.

Efficiency of energy transfer between trophic levels can be studied

b.

Comparisons of pyramids of different trophic levels can be made

c.

More accurate comparisons of trophic levels

d.

Representation of numbers of organisms at different trophic levels.

a.

dormancy

b.

adaptation

c.

extinction

d.

survival

a.

movement of water through the xylem

b.

loss of water vapour from the stomata

c.

translocation of food through the phloem

d.

absorption of water from the soil by the root