Question 7:
Outline a project which aims to find the dominant coat colour in dogs.
Answer:
Dogs have a variety of genes that govern coat colour. There are at least eleven
identified gene series (A, B, C, D, E, F, G, M, P, S, T) that influence coat colour in
dog. A dog inherits one gene from each of its parents. The dominant gene gets
expressed in the phenotype. For example, in the B series, a dog can be genetically
black or brown.
Let us assume that one parent is homozygous black (BB), while the other parent is
homozygous brown (bb)
In this case, all the offsprings will be heterozygous (Bb).
Since black (B) is dominant, all the offsprings will be black. However, they will have
both B and b alleles.
If such heterozygous pups are crossed, they will produce 25% homozygous black
(BB), 50% heterozygous black (Bb), and 25% homozygous brown (bb) offsprings.
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