Biology 9700 · AS & A Level · Natural and artificial selection
Natural and artificial selection — practice question
In continuous variation, a population displays a spectrum of phenotypes between two extremes, with no clear-cut groups. Height and mass are examples of phenotypic traits that show continuous variation.
(a)[3]
Describe how continuous variation is genetically determined.
(b)[2]
Environmental factors can also contribute to continuous variation. Suggest two environmental factors that may influence the body mass of an animal.
(c)[4]
Humans have used selective breeding (artificial selection) for thousands of years to improve livestock quality. Outline the principles behind selective breeding in livestock.
Worked solution & mark scheme
This 9-mark question has a full step-by-step worked solution and mark scheme. One marking point: “Each allele has a small additive effect” …