Black hair is dominant to white hair. A breeder has a black haired male dog that came from 2 black haired parents. The breeder heard that some of the dogs in this family had white hair. He wants to sell this dog to a buyer for a lot of money. The buyer will only buy dogs that do not carry the gene for white hair. What test can he do to show the dog does or does not carry the gene for white hair.
2006-12-06 03:31:24 · 3 answers · asked by vred 1 in Science & Mathematics ➔ Biology
Cross the male dog with a white haired female dog. If all the offspring are black haired, it proves the male dog does not carry the gene for white hair.
2006-12-06 04:30:11 · answer #1 · answered by btpage0630 5 · 0⤊ 0⤋
Assuming there's no DNA test (because if there was, that would be simple to find the answer for)....there is no way to know 100% for sure.
What you can do is mate to a white haired dog. The likelihood of getting a white haired pup is 50%. Say you have a litter of 10 pups and all are black haired. Then the probability that the dog is homozygous black is 1 - (1/2)^10 (basically 1 minus 50% taken to the power of the number of pups). If that happened, you'd be 99.9% positive. Of course, as soon as a white put appears, you are 100% positive that the dog carries a white gene, you just can never be 100% positive that it doesn't.
Just to explain the equation a little more....if the dog is truly a heterozygote, the probability of getting 10 black puppies is 50% * 50% * 50%.....10 times. Subtract that from 1 and you get the probability he's not.
Hope that helps!
2006-12-07 11:51:35 · answer #2 · answered by J.M. R 2 · 0⤊ 0⤋
Probaby perform a test cross, which involves making a Punnett square with the homozygous trait (BB) and homozygous recessive trait (bb).
2006-12-06 11:42:20 · answer #3 · answered by abc123 1 · 0⤊ 0⤋