Question

In goats, a recessive gene causes the goats to "faint" when they are startled. A farmer has a goat that is a carrier for the fainting gene (Gg). Gertrude is mated with one that is homozygous dominant. How many of their offspring will be fainters

Answer 1

Answer:

None

Explanation:

A cross between a heterozygous goat and a homozygous dominant goat would result in no children having the trait.

        G          G

G     GG    |  GG

           --   |   --

g     Gg     |   Gg

Answer 2

Answer:

None

Explanation:

This question states that this particular allele (dubbed "g" ) acts in a recessive manner. This means that the corresponding "fainter" phenotype will be found only when the allele is present in a homozygote state (gg).

If a Gg (heterozygous) goat is mated with a GG (homozygous dominant) goat, it would be expected that approximately 50% of their progeny will be GG and the other 50% will be Gg . Barring the occurrence of de novo mutations, one would not expect any of the offspring to possess an homozygous recessive (gg) genotype and therefore develop as "fainters".