Multiple Allele Traits in Chickens

All chicken have combs on their heads, but it does not always look the same. The comb is a fleshy growth on the top of the chicken's head. Both male and female chickens have combs, but the ones on the male are larger. Combs of different breeds may look different in shape and even in color.

The dash (missing allele) indicates that the allele may be dominant or recessive. It will not affect the phenotype.

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For each cross, indicate the expected phenotypes.

1. Walnut combs (both heterozygotes) RrPp x RrPp

Single _____

Rose ____

Pea ____

Walnut ____

2. Single comb x Walnut (RrPp)

Single _____

Rose ____

Pea ____

Walnut ____

3. Single comb x Pea comb (rrPp)

Single _____

Rose ____

Pea ____

Walnut ____

4. Single comb x Pea comb (rrPP)

Single _____

Rose ____

Pea ____

Walnut ____

5. Rose comb (RrPp) and Pea Comb (rrPP)

Single _____

Rose ____

Pea ____

Walnut ____