Reading the notation

A small set of terms carries every part of this paper — get them precise, since the schedules distinguish genuinely different mechanisms that a vague "genes changed" answer collapses together.

📖 Terms used in genetic variation and change

7 terms

Cover the right column and check you can say what each one means.

Multiple alleles: More than two alleles exist for a gene in the population (e.g. human blood type has three: I^A, I^B, i) — though any one individual still carries only two.
Co-dominance: BOTH alleles are fully and separately expressed in the heterozygote (e.g. AB blood type) — unlike incomplete dominance, where they blend.
Linked genes: Genes located close together on the SAME chromosome, which tend to be inherited together — producing a ratio that deviates from the independent-assortment 9:3:3:1.
Genetic drift: Random change in allele frequencies from generation to generation, due to chance alone — the effect is much stronger in SMALL populations.
Population bottleneck: A sharp, sudden reduction in population size (e.g. by a disaster or over-hunting) that reduces genetic variation, since only the alleles carried by survivors remain.
Founder effect: A new population started by a small number of individuals carries only a small, non-representative sample of the original population's alleles.
Gene flow: The movement of alleles between populations, through migration of individuals — can increase genetic variation in the receiving population.

Practice for this standard covers the whole topic — flashcards and quiz.