Question

A variety of chicken can have all red feathers, all white feathers, or both red

and white feathers. An RR chicken has all red feathers, a WW chicken has
all white feathers, and an RW chicken has both red and white feathers.
A chicken with all red feathers mates with a chicken with all white feathers.
What is the expected phenotypic ratio of the offspring?
3 red: 1 white
all red-and-white feathers
1 red: 2 red-and-white: 1 white
all red feathers

Answer 1

Answer When a chicken with all red feathers (RR) mates with a chicken with all white feathers (WW), their offspring will inherit one allele from each parent.

The genetic cross can be represented as follows:

RR (all red) x WW (all white)

Each parent can only pass on one allele. RR can only pass on an ‘R’, and WW can only pass on a ‘W’.

The offspring genotypes will all be RW (having one ‘R’ allele and one ‘W’ allele) due to the combination of one ‘R’ allele from the RR parent and one ‘W’ allele from the WW parent.

Therefore, all offspring will have red-and-white feathers (RW) phenotypically. The expected phenotypic ratio of the offspring will be 100% red-and-white feathers (RW).