Question

In andalusian fowls black individuals (B) and white individuals (W) are homozygous white bird. the offspring are all bluish-gray show the cross as well as genotypes

Answer 1

In Andalusian fowls, the crossing of homozygous black (BB) and homozygous white (WW) birds results in 100% BW offspring, which have a bluish-gray phenotype due to incomplete dominance.

Step-by-step explanation:

In Andalusian fowls, we have an interesting case of incomplete dominance where neither of the black allele (B) nor the white allele (W) is completely dominant over the other. When these alleles are heterozygous, the phenotype is bluish-gray. To show the cross and genotypes, let's say we have a homozygous black fowl (BB) and a homozygous white fowl (WW). When crossed, their genotypes would produce:

1. All BW (bluish-gray offspring) because B is not completely dominant over W and vice versa, leading to an intermediate phenotype in the F1 generation.

In a Punnett square, this cross would look like this:

B B
W BW BW
W BW BW

All the offspring are BW, which have bluish-gray feathers.

If two BW fowls are then crossed (interbreeding the speckled chickens), the possible genotypes of their offspring would include BB (black), BW (bluish-gray), and WW (white), likely in a 1:2:1 ratio due to incomplete dominance.