Chapter 14

The rates of evolutionary change in DNA:

Are highly variable among different gene families

What is one reason that RNA viruses and retroviruses have such a high rate of mutation?

Because RNA is more fragile than DNA and because viral polymerases lack a proof reading mechanism

Mutations:

Can leave the protein sequence intact

T or F: A silent mutation is a mutation that only occurs in non-coding regions of DNA

False

T or F: DNA ligase is responsible for repairing thymine dimers caused by UV light.

False

T or F: Mutations will always decrease the activity of a gene

False

T or F: Spontaneous mutations that occur in somatic cells will be transmitted to offspring

False

T or F: any DNA "damage" is considered to be a mutation, even if it is immediately corrected by the action of DNA polymerase

False

T or F: any deviation in normal gene dosage is lethal

False

Which mutation would most likely have the most likely have the most severe consequence?

Frameshift

Sites in the genome that are more susceptible to mutations are called

Hotspots

Which of the following would you expect to have the lowest nucleotide nutation rate

Humans

What is the difference between mismatch pair and nucleotide excision repair?

In mismatch repair, one nucleotide is replaced, whereas in nucleotide excision repair several nucleotides are replaced.

A chromosomal mutation where a segment break off, flips,and then reattached itself is called a(n)

Inversion

Sickle-cell anemia is an example of what type of mutation?

Missense

The GAG codon, which codes for gluts mic acid, is mutated to GUG, which now codes for valine. What type of mutation is this?

Missense

Which of the following would describe the action of a chemical compound considered to be a mutagen?

Most are reactive and add bulky side groups to DNA bases

A point mutation that causes a premature stop codon is called a

Nonsense mutation

Chronic mylogeneous leukemia (CML) its caused when a segment of chromosome 9 and segment of chromosome 22 both break off and switch places. How is this mutation classified?

Reciprocal translocation

Which of the following would best describe the results seen in a flower whose sectors have different pigmentation?

The result of transposable elements

A point mutation is when a single nucleotide gets replaced by a different one.

True

Insertion of one nucleotide in a gene will lead to a frameshift mutation. Section: Small insertions and deletions involve several nucleotides.

True

Mutagens increase the amount of damage to DNA

True

T or F: Only germ line mutations are transmitted to the progeny?

True