Mendel, contrary to the fashion of
the day, limited his research to
only one experimental object:
the pea (Pisum sativum).
He only considered clear constant
phenotypic characters which could
be selected than as pairs in a
certain respect.
short stems	long stems
axial flowers	terminal flowers
flower petals purple	flower petals white
green unripe pods	yellow unripe pods
inflated ripe pods	pinched ripe pods
green seed	yellow seed
round seed	wrinkled seed