These crosses are referred to as monohybrid
crosses. The plants involved in the original cross are
call the parental or P generation. The progeny (offspring)
seeds from this cross are referred to as the first
filial or F1 generation.
Mendel found that all the F1 generation seeds resulting
from his original cross of parents with round and
wrinkled seeds were round. (See p. 10-11 to view the
results of Mendel’s crosses.) He concluded that the
wrinkled trait seemed to be masked or “dominated” by
the round trait in the F1 seeds. Mendel called the round
trait dominant and the wrinkled trait recessive. Mendel
planted the F1 seeds, raised the plants, and allowed
them to self-pollinate to produce a second filial or F2
generation of seeds. He found that both round and
wrinkled seeds appeared in the F2 generation in a ratio
of three round (dominant trait) to one wrinkled
(recessive trait).