Question 57 - Science Practice Test for the TEAS

Pea plants can self-pollinate (sperm and eggs both come from the same plant) or they can cross-pollinate (sperm and eggs come from different plants). Gregor Mendel used this to study heredity. He found that if he took a plant that only produced yellow peas and crossed it with a plant that only produced green peas, all the offspring would only produce yellow peas.

On the other hand, if he left the offspring (all yellow pea plants) alone and let them self-pollinate, then the second generation had a ratio of 3:1 yellow to green pea plants. Thus, Mendel could demonstrate that some traits are “dominant” while others are “recessive.”