18.1 Variation
- Syllabus
- 0610–2026–2027
- Topic
- 18.1
- Level
- —
18.1.1—Variation as differences between
- Describe variation as differences between individuals of the same species
18.1.2—Continuous variation results
- State that continuous variation results in a range of phenotypes between two extremes; examples include body length and body mass
18.1.3—Discontinuous variation results
- 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
18.1.4—Discontinuous variation is usually
- State that discontinuous variation is usually caused by genes only and continuous variation is caused by both genes and the environment
18.1.5—Examples of continuous
- Investigate and describe examples of continuous and discontinuous variation
18.1.6—Mutation as genetic change
- Describe mutation as genetic change
18.1.7—Mutation is the way in which new
- State that mutation is the way in which new alleles are formed
18.1.8—Ionising radiation and some chemicals
- State that ionising radiation and some chemicals increase the rate of mutation
18.1.9—Gene mutation as a random change
- Describe gene mutation as a random change in the base sequence of DNA
18.1.10—Mutation, meiosis, random mating
- State that mutation, meiosis, random mating and random fertilisation are sources of genetic variation in populations
Objective notes
10 learning objectivesConceptIGCSE Biology