Answer:
Four
Step-by-step explanation:
As per given data, the cross was done to study the inheritance of two traits: color of kernels (purple or white) and shape of kernels (smooth or wrinkled). The F2 progeny consisted of total 135 kernels which exhibited four categories of phenotypes:
1. purple and smooth (75)
2. white and smooth (28)
3. purple and wrinkled (24)
4. white and wrinkled (8)