An Incompletely Dominant Gene Controls the Color of Chickens So

question 123

Multiple Choice

An incompletely dominant gene controls the color of chickens so that BB produces black, Bb produces a slate-gray color called blue, and bb produces splashed white.A second gene controls comb shape, with the dominant gene R producing a rose comb and r producing a single comb.If a pure-breeding, black chicken with a rose comb is mated to a splashed-white chicken with a single comb in the F₂ generation, what fraction of the offspring will be black with rose comb?

• A)9/16
• B)3/8
• C)3/16
• D)1/8
• E)1/16

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Definitions:

Tay-Sachs Disease

A genetic disorder that destroys nerve cells in the brain and spinal cord progressively due to the absence of a vital enzyme, leading to severe neurological disability and death.

Genetic Drift

Refers to the random fluctuations in the frequency of alleles within a population over time, not due to natural selection.

Sympatric Speciation

Speciation pattern in which speciation occurs within a population, in the absence of a physical barrier to gene flow.

Physical Barrier

Any natural or artificial structure that blocks or limits movement, spread, or access of organisms or materials.