Phenylketonuria is an inherited disease caused by a
recessive autosomal allele. If a woman and her
husband are both carriers, what is the probability that
their first child will be a phenotypically normal girl?
1.
2.
3.
4.
5.
1/4
1/16
1.0
3/16
3/8
Phenylketonuria is an inherited disease caused by a
recessive autosomal allele. If a woman and her
husband are both carriers, what is the probability that
their first child will be a phenotypically normal girl?
1.
2.
3.
4.
5.
1/4
1/16
1.0
3/16
3/8 -- 3/4 healthy x 1/2 girl.
Assuming independent assortment for all gene
pairs, what is the probability that the following
parents, AABbCc  AaBbCc, will produce an
AaBbCc offspring?
1. 1/2
2. 1/16
3. 1/8
4. 3/4
5. 9/16
Assuming independent assortment for all gene
pairs, what is the probability that the following
parents, AABbCc  AaBbCc, will produce an
AaBbCc offspring?
1. 1/2
2. 1/16
3. 1/8
4. 3/4
5. 9/16
A sexually reproducing organism is heterozygous for
two genes located on different chromosomes, one
for ear shape and one for toe length. Its genotype is
AaBb. Which of the following genotypes is most
probable in a gamete from this organism?
1. AB
2. AaBb
3. Aa
4. Bb
5. A
A sexually reproducing organism is heterozygous for
two genes located on different chromosomes, one
for ear shape and one for toe length. Its genotype is
AaBb. Which of the following genotypes is most
probable in a gamete from this organism?
1. AB
2. AaBb
3. Aa
4. Bb
5. A
Pseudohypertrophic muscular dystrophy is a human
disorder that causes gradual deterioration of the
muscles. It is seen only in boys born to apparently
normal parents and usually results in death in the
early teens. It is likely that this gene is ______ and
______.
1. recessive; sex-linked
2. dominant; sex-linked
3. recessive; autosomal (not sex-linked)
4. codominant; sex-linked
5. incompletely dominant; autosomal (not sex-linked)
Pseudohypertrophic muscular dystrophy is a human
disorder that causes gradual deterioration of the
muscles. It is seen only in boys born to apparently
normal parents and usually results in death in the
early teens. It is likely that this gene is ______ and
______.
1. recessive; sex-linked
2. dominant; sex-linked
3. recessive; autosomal (not sex-linked)
4. codominant; sex-linked
5. incompletely dominant; autosomal (not sex-linked)
Whenever either or both gene A or gene B is
present, red color is produced. A cross of AaBb 
AaBb would be expected to yield how many red
offspring out of 16? Assume the genes are not
linked.
1. 1
2. 4
3. 12
4. 15
5. 16
Whenever either or both allele A or allele B is
present, red color is produced. A cross of AaBb 
AaBb would be expected to yield how many red
offspring out of 16? Assume the genes are not
linked.
1. 1
2. 4
3. 12
4. 15
5. 16