This is a dihybrid cross. Punnet square will have 16 squares. Parakeet coloration
is determined by the interaction of two genes: B series and C series. These are the
possibilities:
B-C-
B-cc
bbc-
bbcc
The dash means either allele: the pair could be homozygous or heterozygous.
Green
Blue
Yellow
White
What would be the probability for the offspring if both parents were Bbcc
and bbcc? What color are the parent birds? What is the phenotypic ratio of
the offspring?