1. 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?
1/4
1/16
1.0
3/16
3/8
Answer: 5
Question Type: Conceptual/Applied
Question Skill/Objective: General
Difficulty level: Moderate
Section Reference: 13.1
Source/Suggested Use: Exam or In Class
Notes: This problem blends a monohybrid cross results with the likelihood of having a girl.

2. 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?
1/4
1/16
1.0
3/16
3/8 -- 3/4 healthy x 1/2 girl.

3. Assuming independent assortment for all gene pairs, what is the probability that the following parents, AABbCc  AaBbCc, will produce an AaBbCc offspring?
1/2
1/16
1/8
3/4
9/16
Answer: 3
Question Type: Conceptual/Applied
Question Skill/Objective: General
Difficulty level: High
Section Reference: 13.2
Source/Suggested Use: Exam or In Class
Notes: Class time could be used to have students see a simple shortcut method for arriving at the correct answer rather than using tedious Punnett square methods.

4. Assuming independent assortment for all gene pairs, what is the probability that the following parents, AABbCc  AaBbCc, will produce an AaBbCc offspring?
1/2
1/16
1/8
3/4
9/16

5. 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? AB
AaBb Aa Bb A
Answer: 1
Question Type: Conceptual/Applied
Question Skill/Objective: General
Difficulty level: Moderate
Section Reference: 13.3
Source/Suggested Use: In Class
Notes: This would be a good question to help students understand the relationship between chromosome behavior in meiosis (Chapter 12) and Mendelian genetics (Chapter 13)

6. 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? AB
AaBb Aa Bb A

7. recessive; sex-linked dominant; 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 ______.
recessive; sex-linked
dominant; sex-linked
recessive; autosomal (not sex-linked)
codominant; sex-linked
incompletely dominant; autosomal (not sex-linked)
Answer: 1
Question Type: Conceptual/Applied
Question Skill/Objective: General
Difficulty level: High
Section Reference: 13.4
Source/Suggested Use: Exam or In Class
Notes:

8. 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 ______.
recessive; sex-linked
dominant; sex-linked
recessive; autosomal (not sex-linked)
codominant; sex-linked
incompletely dominant; autosomal (not sex-linked)

9. 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 4 12 15 16
Answer: 4
Question Type: Conceptual/Applied
Question Skill/Objective: General
Difficulty level: Moderate
Section Reference: 13.5
Source/Suggested Use: Exam
Notes:

10. 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 4 12 15 16