GENETICS 310
STUDY GUIDE FOR EXAM 3

 

Give examples of single gene defects (dominant and recessive) that cause increased incidence of cancer.

What is the normal function of genes that can increase cancer risk following mutation?

Draw the genetic map of a typical retrovirus, and of an oncogenic retrovirus.

List common examples of sex-linked genes. Show the progeny expected in crosses where the a) male b) female carrier of a sex-linked recessive is crossed to a normal. Do the same for a sex-linked dominant.

Name and describe the phenotypes of the following sex chromosome abnormalities: XXX, XYY, XO, XXY.

Define and give examples of sex-limited inheritance, sex-influenced inheritance, genomic imprinting and and the Lyon hypothesis.

The cross A b/a B X a b/a b gave 10% double homozygous recessive progeny. What is the map distance between genes A and B? Is the first parent in coupling?

How were human genes first located to specific chromosomes?

Define and give an example of: trisomy, triploidy, a hexaploid plant, and deletion.

Show how synapsed chromosomes would appear in heterozygotes for a deletion, a duplication, an inversion, and a translocation. What role might these aberrations play in forming new species?

Give three different types of tests that can be used to detect genetic defects following amniocentesis, and an example of each.

What is PCR? List the components and describe the protocol. Give examples of how it can be used.

What is meant by transgenic animals? superovulation?

Calculate gene frequencies from given populations.

Examples:
1) 30AA, 40Aa, and 30aa.
2) 91% A_ and 9% aa.

What genotypic frequencies would you expect in these populations if random mating occurred?

List the forces that can change gene frequencies.

What happens to gene frequencies and genotypic frequencies when inbreeding occurs?