In Pisum sativum, purple flowers are dominant to white flowers. When two white flowered plants are cross, what percentage of their offspring will be white flowered?

Since white flowers are the recessive traits in Pisum sativum, the genotype of the parents would be pp x pp, where P= gene for a purple flower and p= gene for a white flower. Because it is a recessive trait, both white flowered parents must be homozygous recessive. Therefore, all of their offsprings will also have white flowers, because that is the only gene available.