Question

1) What would be the % of possible offspring that would develop cystic fibrosis from the mating of 2 parents with Ff genotypes, Cystic fibrosis is caused by the recessive alle(f)

2) What cross can produce some dark coat offspring, if in American Albino horses the albinism allele(A) resulted in a white coat which is dominant over the allele of the darker coat color?

Answer 1

1) What would be the % of possible offspring that would develop cystic fibrosis from the mating of 2 parents with Ff genotypes, Cystic fibrosis is caused by the recessive alle(f)

	F	f
F	FF normal	Ff normal
f	Ff normal	ff cystic fiborsis

Four are total genotypic possibilities and two are phenotypic possibilities in offspring out of which 1 is cystic fibrosis

Then 1/4*100=25 % in F1 generation

2) What cross can produce some dark coat offspring, if in American Albino horses the albinism allele(A) resulted in a white coat which is dominant over the allele of the darker coat color?

Parents both with heterozygous for recessive alleles when mated may result in 1 out of 4 i.e. 1/4*100= 25% of offspring as darker coat color.

	A	a
A	AA albino	Aa albino
a	Aa albino	aa dark coat