In guinea pigs, the gene for black coat color dominates over white coat color. Short-haired is determined

In guinea pigs, the gene for black coat color dominates over white coat color. Short-haired is determined by the dominant gene, while long-haired is determined by the recessive gene. Genes for coat color and length are inherited independently. A homozygous black long-haired animal was crossed with a homozygous white short-haired animal. What offspring will be obtained from crossing the first generation gilts with a heterozygous pig in color and homozygous for coat length?

Let’s designate the gene for the black color of guinea pigs’ fur as C, then the gene that leads to the development of white hair in them will be c.

We will designate short-haired as P, then the gene for long hair will be p.

The long-haired black guinea pig is homozygous according to the condition. Let’s write it as CCpp. This guinea pig produces sex cells Cp.

The white short-haired individual is also homozygous, we write it as follows: ccPP. It will produce cP germ cells.

All F1 obtained by crossing the described guinea pigs will be CcPp, that is, black short-haired animals. They, in turn, produce germ cells СР, Ср, Ср, СР.

A guinea pig that is heterozygous in color and homozygous in length can be either CcPP or Ccpp.

Consider both options.

Guinea pig – СcРР. It produces sex cells CP and CP. By crossing it with the descendant F1, we get the offspring of the type:

black short-haired guinea pigs (CCPP, 2 CCPp, CCPp, 2CcPP);

white short-haired cubs (ccPp, ccPP).

Guinea pig – Ccpp, Cp and cp germ cells produced by it.

Offspring:

black shorthaired cubs (CCPp, 2CcPp);

black long-haired cubs (2 Сcpp, CCpp);

white long-haired (ccpp);

white shorthair (ccPp).