Ch. 3prb..21>>> 21. (Problem 23) Hairlessness in American rat terriers is recess
ID: 311352 • Letter: C
Question
Ch. 3prb..21>>>
21.
(Problem 23) Hairlessness in American rat terriers is recessive to the presence of hair. Suppose that you have a rat terrier with hair. How can you determine whether this dog is homozygous or heterozygous for the hairy trait?
21.
(Problem 23) Hairlessness in American rat terriers is recessive to the presence of hair. Suppose that you have a rat terrier with hair. How can you determine whether this dog is homozygous or heterozygous for the hairy trait?
A. Cross your rat terrier with a rat terrier with hair from the same litter as your rat terrier. B. Cross your rat terrier with a hairless rat terrier. C. Cross your rat terrier with a rat terrier with hair from a different litter than your rat terrier. D. All of the above are crosses that would allow you determine if your rat terrier is heterozygous or homozygous. E. Cannot be determinedExplanation / Answer
21. The answer is: B. Cross your rat terrier with a hairless rat terrier.
Hairless rat terrier are homozygous recessive so this cross will be known as test cross. If all offspring have hair then the dog is homozygous, if ha;f of the offsprings have hair and other half are hair less then dog is heterozygous.
22. The answer is: C. 1/6
Probability of the event = favorable number of outcomes / total number of outcomes = 1/6.
3. The answer is: A. 1/3.
Probability = 1/6 + 1/6 = 1/3
4. The answer is: D. 5/6
Probability = 1 - 1/6 = 5/6