Biology · IGCSE · Cambridge · Cambridge IGCSE (9–1) Biology 0970 (Extended) (2026–2028) · Specification point · 18.1 · Variation and selection
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18.1 Variation
| Core | Supplement |
|---|---|
1 Describe variation as differences between individuals of the same species | |
2 State that continuous variation results in a range of phenotypes between two extremes; examples include body length and body mass | |
3 State that discontinuous variation results in a limited number of phenotypes with no intermediates; examples include ABO blood groups, seed shape in peas and seed colour in peas | |
4 State that discontinuous variation is usually caused by genes only and continuous variation is caused by both genes and the environment | |
5 Investigate and describe examples of continuous and discontinuous variation |
6 Describe mutation as a genetic change | 9 Describe gene mutation as a random change in the base sequence of DNA |
7 State that mutation is the way in which new alleles are formed | 10 State that mutation, meiosis, random mating and random fertilisation are sources of genetic variation in populations |
8 State that ionising radiation and some chemicals increase the rate of mutation |