Variation seen for a characteristic within a species may be described as discontinuous or continuous. Discontinuous variation has a different genetic basis from continuous variation. State two differences between discontinuous variation and continuous variation, apart from having a different genetic basis.
Fig. 9.1 displays three of the colour patterns found in \emph{H. axyridis} together with the percentage of each pattern in a population. Suggest the genetic basis of the variation in colour pattern in \emph{H. axyridis}.
The body size of adult \emph{H. axyridis} ranges from $5\,\text{mm}$ to $8\,\text{mm}$. Adult ladybirds do not grow or change size. They develop from larvae that hatch from eggs. State two environmental factors that may affect adult body size in \emph{H. axyridis}.