Mendell crossed a true-breeding plant with yellow peas to a true-breeding with green peas. All first generation plants had yellow peas. Using your understanding of the cause-and-effect relationship between cross-pollination and inherited traits, explain which trait is recessive.

The green trait

Explanation:

Because when the genetic cross is done, all the first generation plants have the yellow trait meaning the yellow trait is dominant over the green one therefore it masks the expression of the recessive trait (green trait)

the correct option is option a

they deliver oxygen to the blood