A.    Assume that the ability to taste PTC and to roll one's tongue are both dominant traits
        determined by genes on separate chromosomes.

What is the probability of a first born being able to roll its tongue and taste PTC if its parents have the genotypes RrTt and Rrtt?    a)    9/16 b)    1/2    c)    3/8   d)    1/16     (answer = c)
 
1. What is the probability of a first born being able to roll its tongue and taste PTC if its parents have the genotypes rrTt and Rrtt?    a)    9/16 b)    1/2    c)    1/8   d)    1/4
2. What is the probability of a first born being able to roll its tongue and taste PTC if its parents have the genotypes RrTt and RrTt?    a)    9/16 b)    1/2    c)    1/8   d)    1/4
3. What is the probability of a first born being able to roll its tongue and taste PTC if its parents have the genotypes RrTt and RRtt?    a)    9/16 b)    1/2    c)    1/8   d)    1/4
4. What is the probability of a first born not being able to roll its tongue and not taste PTC if its parents have the genotypes RrTt and Rrtt?    a)    9/16   b)    1/2    c)    1/8    d)    1/4

(answer = a)

1. A man who carries a recessive X-linked allele marries a woman who is heterozygous.  Which of their children will have the recessive phenotype?
a)    all his daughters b)    half of his daughters    c)    all of his sons    d)    half of his sons
e)    half of his daughters and half of his sons
2. A man who carries a recessive X-linked allele marries a woman who has the dominant phenotype but her father had the recessive phenotype.  Which of their children will have the recessive phenotype?
a)    all his daughters b)    half of his daughters    c)    all of his sons    d)    half of his sons
e)    half of his daughters and half of his sons
3. A man who carries a dominant X-linked allele marries a woman who has the recessive phenotype.  Which of their children will have the recessive phenotype?
a)    all his daughters b)    half of his daughters    c)    all of his sons    d)    half of his sons
e)    half of his daughters and half of his sons
4. A man who carries a dominant X-linked allele marries a woman who has the recessive phenotype.  Which of their children will have the dominant phenotype?
a)    all his daughters b)    half of his daughters    c)    all of his sons    d)    half of his sons
e)    half of his daughters and half of his sons

The views and opinions expressed in this page are strictly those of the page author.
The contents of this page have not been reviewed or approved by the University of Minnesota.