Assume that corn plants have a diploid number of only 2. In the following figure, the male plant's chromosomes are diagrammed on the left, and those of the female are diagrammed on the right.

Diagram sex-cell formation in the male and female plant. How many variations in sex cells can occur and what are they? What variations can occur in the production of chlorophyll and starch in the descendants of these parent plants?

What illustrations in the text resemble this process? What does crossing-over have to do with variation? What other sources of variation might play a role here? How would you show these in a diagram?