1. Fig. 1 shows changes in the populations of snowy owls and lemmings over a three year period.

Fig. 1

During the first 10 months of year 1, the lemming population increases slowly at first and then more rapidly.

(i)

Suggest why the rate of increase becomes greater.

[1]

(ii)

Suggest why the lemming population falls during year 2.

[2]

(iii)

Use Fig. 1 to describe and explain how changes in the lemming population affect the snowy owl population.

[3]

(iv)

If all the snowy owls were removed from the Arctic ecosystem, suggest and explain what effect this would have on the lemming population in the following years.

[3]