Describe5 marksStandard
A biologist studies two traits in a population of wild roses. Trait A is flower colour: individual plants produce either red or white flowers, with no intermediate shades. Trait B is leaf length, measured in millimetres; the leaves show a continuous range from 30 mm to 80 mm, with most leaves around 55 mm. The biologist also notes that leaf length is influenced by rainfall.
Using the examples of flower colour and leaf length in these wild roses, describe the differences between discontinuous and continuous variation, explain the genetic basis of each type of variation, the role of environmental factors, and how a t‑test could be used to compare mean leaf lengths between two samples.