(a)[3]
Describe the negative effects on an ecosystem of large-scale monocultures, such as the one shown in Fig. 6.1.
(b)[2]
State two desirable features visible in Fig. 6.2 that were selected from the older varieties of maize.
(c(i))[1]
Explain why the flowers are enclosed in bags in step 3.
(c(ii))[2]
Explain why the seeds in step 4 require oxygen in order to germinate.
(c(iii))[1]
Explain why some plants in step 5 may display characteristics that were not visible in the parent plants.
(c(iv))[2]
Suggest why selective breeding should be continued over many generations (step 6).
(c(v))[1]
State how new features, which were absent from ancient varieties of a crop plant, could arise.