Question

Plan a breeding program that would produce all Himalayan rabbit offspring when starting with one albino parent(cc) and one dark grey parent known to be Cch

Answer 1

Data given is incomplete. It has been attached.

Answer:

According to the data provided,

Albino rabbit = cc

Dark gray rabbit = Cch

When they mate ( Cch X cc ),

C ch

c Cc chc

c Cc chc

Out of the resultant progeny, chc genotype rabbits will have Himalayan phenotype since ch allele is dominant over c allele. These chc rabbits should be mated with each other:

chc X chc :

ch c

ch chch chc

c chc cc

The resultant progeny has chch (himalayan), chc (himalayan) and cc (albino) genotype rabbits. We want parents which only produce himalayan rabbits. So our desired genotype is homozygous himalayan rabbits (chch). To identify which himalayan rabbits are chch, we will perform a test cross of himalayan rabbits from this progeny with albino rabbits (cc).

In a test cross if the himalayan rabbits are chch, all the rabbits from the resultant progeny will be himalayan as shown :

ch ch

c chc chc

c chc chc

Select these rabbits as they are homozygous Himalayan rabbits. They only have ch allele. When they are mated to each other ( chch X chch ), all the rabbits in the resultant progeny will be purebred Himalayan rabbits ( chch ).