In Chickens, Comb Shape Is Determined by Genes at Two

question 21

Multiple Choice

In chickens, comb shape is determined by genes at two loci (R, r and P, p) .A walnut comb is produced when at least one dominant gene R is present at one locus and at least one dominant gene P is present at a second locus (genotype R_ P_) .A rose comb is produced when at least one dominant gene is present at the first locus and two recessive genes are present at the second locus (genotype R_ pp) .A pea comb is produced when two recessive genes are present at the first locus and at least one dominant gene is present at the second (genotype rr P_) .If two recessive genes are present at the first and the second locus (rr pp) , a single comb is produced.Give genotypes for comb shape of the parents in the following cross: rose crossed with pea produces two walnut, one single, and one pea offspring.

• A)RR pp × rr PP
• B)Rr pp × rr Pp
• C)Rr pp × rr PP
• D)RR pp × rr Pp
• E)Rr pp × Rr Pp

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Definitions:

Negative Exponential

A statistical distribution used to model time between independent events that occur continuously at a constant average rate.

Service Times

The duration a customer has to wait before receiving a service or the time taken to deliver a service.

Poisson Distributions

A distribution in statistics showing the chances of a specified number of occurrences within a set period of time or area.