Question

(a) Fig. 4.1 shows some different sources of pollution of the water in seas.

(i) Complete the sentences using information from Fig. 4.1.
The two biggest sources of pollution are ………………………………………… and ………………………………………… .
The total percentage of pollution caused by chemical waste is ………………………………………… %.
The percentage of pollution caused by discarded rubbish is ………………………………………… %.
(ii) Suggest one negative impact of untreated sewage on humans.

(b) Polluted water affects the growth of plants.
A scientist measures the height of two pea plants, A and B, for one month.
Plant A is given unpolluted water.
Plant B is given polluted water.
Table 4.1 shows the increase in height for each plant.

(i) Calculate the difference in increase in height between plant A and plant B from Table 4.1.
…………………………………………………………………………………………….. cm [1]
(ii) Water is needed for germination of seeds.
State two other environmental conditions required for germination.
1 ……………………………………………………………………………
2 …………………………………………………………………………..