Exam 10: Genetic Linkage, Sex-Linkage, and Other Non-Mendelian Inheritance Mechanisms

Consider the following genetic study involving two autosomal genes. One of these, eye colour, has the dominant allele (R) for red eye colour and the recessive allele (r) for yellow eye colour. The other has the dominant allele (T) leading to paws with thumbs, while the recessive allele (t) codes for paws without thumbs. If these genes are not linked, what should be the phenotype ratio of the offspring produced by a testcross (RrTt × rrtt)?

How does the age of the mother seem to correlate with the incidence of genetic birth defects?

Figure 10-1 -In Figure 10-1, what type of change in the chromosomes is depicted?

What is caused by the human genetic condition called Leber's hereditary neuropathy?

Suppose an individual is born with both an X and a Y chromosome, but the Y chromosome has a mutation that eliminates the function of the SRY gene. How would this person appear phenotypically?

About 4% of people of northern European descent are carriers for an autosomal recessive genetic disorder in which a defective membrane transport protein leads to abnormal chloride levels in extracellular fluids. What is the name of this disorder?

Which of the following is most likely to happen to a human polyploid?

Suppose that you examine a vial of 100 flies that are all offspring from a single genetic cross. Also suppose that you find both red-eyed females and white-eyed females, as well as both red-eyed males and white-eyed males. The allele for red eye colour (X^w+) is dominant over the allele for white eye colour (X^w). Which of the following describes the genotypes of the parents?

Match each of the following genetic conditions with its mode of inheritance. A mode of inheritance may be used once, more than once, or not at all. -phenylketonuria

Figurer 10-3 -In Figure 10-3, what type of change in the chromosomes is depicted?

Which term refers to an individual with three or more copies of each of their chromosomes?

Match each of the following genetic conditions with its mode of inheritance. A mode of inheritance may be used once, more than once, or not at all. -Down syndrome

Which of the following kinds of information can be revealed through a family pedigree analysis?

Suppose that crossing-over during meiosis occurs within a region where one of the homologous chromosomes has an inversion with respect to the other homolog. Which chromosomal alteration would you expect to find in the gametes produced by this organism?

Which scientist was responsible for the characterization of linked genes?

Suppose that you examine a vial of 100 flies that are all offspring from a single genetic cross. Suppose also that you see that all the females present are red-eyed and all the males present are white-eyed. The allele for red eye colour (X^w+) is dominant over the allele for white eye colour (X^w). Which of the following describes the genotypes of the parents?

Most hospitals routinely test all newborns for an autosomal recessive disorder in which an enzyme in amino acid metabolism is NOT produced. In this disorder, lack of the enzyme leads to a buildup of compounds that damage brain tissue, possibly leading to mental retardation, unless a restricted diet is followed. What is the name of this disorder?

In humans, which condition does sex determination generally depend upon?

Suppose that a man and woman have a son with a rare genetic disorder known to be X-linked. There is no occurrence of the disorder on the woman's side of the family, but the man's brother has it, as does her father. What is the probability that the son's defective allele came from the man?

Which of the following processes is most likely responsible for many mammals having multiple hemoglobin genes?