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
State that ionising radiation and some chemicals increase the rate of mutation
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
Explain the risks to a species if its population size decreases, reducing genetic variation (knowledge of genetic drift is not required)