Older MCQs might not have the typical A, B, C,
D
choices. They
have choices 1, 2, 3, and a combination of them is the answer. Below is the key that maps such
combinations to the answer.
A
1, 2 and 3 are correct
B
1 and 2 only are correct
C
2 and 3 only are correct
D
1 only is correct
Explain the process of eutrophication of water, limited to: - increased availability of nitrate and other ions - increased growth of producers - increased decomposition after death of producers - increased aerobic respiration by decomposers - reduction in dissolved oxygen - death of organisms requiring dissolved oxygen in water
Describe the reasons for habitat destruction, including: (a) increased area for housing, crop plant production and livestock production (b) extraction of natural resources (c) freshwater and marine pollution