Genetics - Mutations

Question 1

What is a mutation? Mutations collected over time cause changes to the ______? Some are spontaneous, others are a reaction w a ______.

Answer 1

Small-scale change in nucleotide sequence of DNA. Changes genome. May be caused by reaction w mutagen.

Question 2

Examples of mutagens?

Answer 2

radiation: gamma, x-rays, microwaves
chemicals: tar in cigs

Question 3

Mutations could have no effects (_______) or catastrophic events.

Answer 3

benign

Question 4

What percent of human DNA is non-coding? A point mutation that has no effect on the functioning genome is called a ______ mutation.

Answer 4

98.5%, silent

Question 5

Mutations in the coding regions could also be _______. Ex. a point mutation to GAA converts the codon to GAG but both code for Gly

Answer 5

silent

Question 6

What is a mis-sense mutation?

Answer 6

A point mutation that changes a codon so that a different protein is specified

Question 7

A gene can tolerate a few amino acid ______ before biological function is changed. What kind of mutation is this?

Answer 7

changes. Missense (single diff protein is produced)

Question 8

What type of mutation coverts a codon that specifies an amino acid into a stop codon? How long is the protein? What are the effects?

Answer 8

Nonsense, short, catastrophic (non-functional protein)

Question 9

What are the two types of frameshift mutations?

Answer 9

Addition or deletion of a single nucleotide that changes the entire reading frame of mRNA

Question 10

The deletion of a single nucleotide (A, T, C or G) changes all the codon __________ from the change.

Answer 10

downstream.