Biology

Samantha Cooley

26 August, 14:43

2. In dogs, there is an hereditary deafness caused by a recessive gene, "d." A kennel

owner has a male dog that she wants to use for breeding purposes if possible. The dog

can hear, so the owner knows his genotype is either DD or Dd. If the dog's genotype is

Dd, the owner does not wish to use him for breeding so that the deafness gene will not

be passed on. This can be tested by breeding the dog to a deaf female (dd). Draw the

Punnett squares to illustrate these two possible crosses. In each case, what

percentage/how many of the offspring would be expected to be hearing? deaf? How

could you tell the genotype of this male dog? Also, using Punnett square (s), show how

two hearing dogs could produce deaf offspring.