He noticed that 2 types of Pea plants gave
very uniform results when breed within their
own gene pool and not with one another. The
traits he noticed where:
(This is not a punnet square. Just an example
to show the different phenotypes seen in two
different Pea plant strains.)
He noticed that the offspring all carried
the same traits when they breed in with the
same population or gene pool.
Now since there where no variations in with
each strain he guessed that both strains where
homozygous for these traits. Because the pea
plants where from the same species Mendel
guessed that either the Solid seed shells where
recessive or the wrinkled seed shells where
recessive. So he used the genotype notations
(SS for solid, ss for wrinkled). He knew that
they could not be Ss, because one lot did not
produce any of the other strain’s phenotypes
Pea Plant #1 Pea Plant #2
Solid seed shells Wrinkled seed shells
Green seeds Yellow seeds
White flowers Purple flowers
Tall plants Short plants
