There were 800 males in the control population.

Each male made one type of call.

Use this information and Table 6 to calculate the number of males making mating calls in the control population.

Answer ______________ males

Suggest one change the scientists could make to both frog populations to increase the number of mating calls.

The scientists also investigated the effect on female frog courtship behaviour of feeding EE2 to male frogs.

Table 7 shows their results.

EE2 is contained in human contraceptive pills. Some EE2 is released in human urine and collects in sewage. Untreated sewage pollutes the water in frog habitats.

Suggest and explain the effect EE2 pollution in frog habitats will have on frog breeding.

Use information from Table 6 and Table 7 in your answer.

Effect on frog breeding

Explanation