1. Determine the ultimate effect in an XY human with its SRY gene mutated?

2. In humans, the allele for brown eye (B) is dominant to blue (b) eye color. If two heterozygous parents produce children, what is the probability that:

a. The first child has brown eyes, and the next two children have blue eyes?

b. If the couple above eventually produces a total of six children, what is the probability that three of them will be boys with brown eyes, and three of them girls with blue eyes?

3. In a paternity dispute, a type AB woman claimed that one of the four men was the father of her type A child. Which of the following men could be the father of the child on the basis of the evidence below? Give your reasoning.

Man #1 = type A

Man #2 = type B

Man #3 = type O

Man #4 = type AB

4. Several mating were made among all-white cats. The progent from these mating showed the following phenotypic frequency:

All-white cats = 12/16

Black cats = 3/16

Gray cats = 1/16

a. Diagram the cross showing the genotypes of the parents, and their progeny as given above,

b. Which gene is epistatic? Explain your answer.

 

5. Mitosis and meiosis differ in that

a. homologues are seperated in prophase of mitosis

b. homologues are seperated in prophase I of meiosis

c. homologues are seperated in prophase II of meiosis

d. sister chromatids are seperated in prophase I of meiosis

 

6. The phases of meiosis that most resemble those of mitosis are

a. the meiosis I phase

b. the meiosis II phase

c. meiosis I, except for the pairing of homologues

d. meiosis II, except for the pairing of homologues

 

7. Genetic variability in sexually reproducing organism s arises from

a. crossing over events between sister chromatids

b. crossing over events between nonsister chromatids

c. egg and sperm genetic recombination from distinct individuals

d. egg and sperm recombination from an individual

 

8. A female contains an extra X chromosome, resulting from nondisjunction. When this gamete is fertilized with normal sperm, it would result in an individual of a genotype

a. XXX

b. XXY

c. XYY

d. all of the above

e. only a and b

 

9. A diploid organism has the genotype AaBbCcDdEe. How many different types of gametes can this individual produce?

a. 5

b. 10

c. 25

d. 32

e. 625

 

10. Assuming complete dominance, what is the phenotype ratio of the offspring of the cross AaBb x aabb?

a. 1:1

b. 3:1

c. 1:2:1

d. 1:1:1:1

e. 9:3:3:1