Question

A swine producer who raises hogs to sell at the market has decided to use some genetics to increase the size of his animals so that he can get a better price at market. Currently his hogs are about the average size of his fellow producers across the county. He breeds his sows with semen collected from a boar that is 1.5 times larger than his current stock. The litter is 6 in number and looks promising. However, when these animals are ready for market 7 months later, only half the animals are as large as the boar. The producer wants to get some credit back from the semen supplier for defective semen.

Based on what you know about Mendelian genetics, what can you tell the producer about his claim to having been sold “defective semen”

Answer 1

On breeding the Producer got only 50% of the stocks are larger.This can be possible ,if the trait for the Size in boar is dominant heterozygous .

For example Assume the Allele for size(A) is Dominant in boar and allele for the size(a) are recessive .

and Boar is heterozygous for the trait ; Genotype of Boar :Aa

while Hogs are homozygous for the trait ;Genotype of hogs : aa

Thus on crossing :

Aa X aa

	A	a
a	Aa(larger size)	aa(normal size)
a	Aa(larger size)	aa(normal size)

Thus 50% of population is of larger size like Boar and 50% are normal in size like hogs.

So the result is due to Law of dominance and independent assortment of alleles.and claim by producer for having been sold defective sperm is not correct.