Monohybrid cross in mice
In mice, a locus (B) at a particular point on a
particular chromosome in mice influences black or brown fur.
Each Bb parent
produces equal numbers of B
and b gametes.
Random union of B
and b gametes
produces four possible combinations: BB, Bb , bB,
and bb, at equal
frequencies, of which three (BB, Bb, and bB) produce black
offspring due to the dominance of the B allele to
the b allele, and one (bb) produces a brown offspring by
reinforcement of the b allele. Thus the mating of
two heterozygous black mice produces the expected ratio of 3
black : 1 brown offspring.
Figure ©2002 by Griffiths et al;. all text material ©2016 by Steven