Question

dihybrid genetic crosses – chickens!
trait | dominant allele | recessive allele
feather color | white (w) | speckled (w)
number of toes | five (f) | three (f)
comb color | hot pink (p) | baby blue (p)
sound it makes | cluck (c) | woof (c)
suppose you have a homozygous white, five - toed rooster (wwff) and you cross it with a heterozygous white, three - toed hen (wwff). answer the following questions about this cross.
a. list the possible gamete combinations for the rooster:
b. list the possible gamete combinations for the hen:
c. perform the following dihybrid cross:
table with empty cells
d. what are all of the possible genotypes of the offspring?
e. what are all of the possible phenotypes of the offspring, and in what ratio?
suppose you cross a rooster that has a baby blue comb and is heterozygous for a cluck with a hen heterozygous for a hot pink comb and makes a \woof\ sound.
a. what is the genotype for the rooster?
b. what is the genotype for the hen?

Explanation:

Step1: Rooster's gametes

Rooster genotype: WWFF → only WF gamete.

Step2: Hen's gametes

Hen genotype: Wwff → gametes Wf, wf.

Step3: Punnett square setup

Rows: Rooster gamete WF
Columns: Hen gametes Wf, wf

	Wf	wf

Step4: Offspring genotypes

From square: WW Ff, Ww Ff.

Step5: Phenotypes

All white (W dominant), 5-toed (F dominant) → 1:1 ratio.

Step6: Second part rooster genotype

Baby blue comb (pp), heterozygous cluck (Cc) → pp Cc.

Step7: Second part hen genotype

Heterozygous hot pink (Pp), woof (cc) → Pp cc.

Answer:

a. WF
b. Wf, wf
c. (See Punnett square below)
d. WW Ff, Ww Ff, WW ff, Ww ff
e. White, five-toed (1:1) and white, three-toed (1:1) (ratio 1:1)
Second part:
a. pp Cc
b. Pp cc