What is the difference between UV-A, UV-B, and UV-C radiation?

UVC is the shortest and not long enough to reach our skin; UVB rays come in contact with the outer layer of the skin; UVA radiation penetrates deeper into the skin, all the way into the inner layers. UVC rays are actually the strongest but are mostly absorbed by the atmospheric ozone.

Explanation:

the offspring would all be white. if the parents are both white flowers then they have the genotype rr, which when crossed results in an all white punnet square.