Question 7
Outline a project which aims to find the dominant coat colour in dogs.
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 the 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 phenotypically black or brown.
Let us assume that one parent is homozygous black (BB), while the other parent is homozygous brown (bb)
BBbbBBbBbBbbBbBb
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.
BbBBBBbbBbbb