Theme 4 - Module 4 (DNA Mutations)

Question 1

How can mutation be propagated?

Answer 1

Incorrect nucleotide bases are then used as a template in the next round of replication, leading to the propagation of mutation

Question 2

Organism with the highest mutation rate?

Answer 2

Viruses

Specifically RNA viruses

Question 3

Why do RNA viruses have high mutation rates?

Answer 3

• delicate RNA backbone (more prone to damage and breakage)

- no proofreading capability in RNA genomes

Question 4

If a mutation occurs in a somatic cell, what will occur once the cell divides?

Answer 4

Cell will be the progenitor of a population of identical daughter cells following cell division

(lead to a patch or region of cells with that new mutation)

Question 5

True or false: if a mutation arises in a somatic cell that is no longer dividing, or is post-mitotic in the G0 cycle, then the effect of a mutation may be largely negligible

Answer 5

True

Question 6

True or false: if a mutation arises in a somatic cell that is early in the developmental cascade, the effect of the mutation is largely negligible

Answer 6

False

The earlier it is, the larger the spread of the mutated somatic cells throughout the body

Question 7

True or false: somatic mutations can be passed onto progeny

Answer 7

False

Only germ cells can be passed on

Question 8

Why can germline mutations be passed on to progeny?

Answer 8

Bc germ cells are the cells that come together to produce new offspring in sexually reproducing organisms

Question 9

True or false: if a germline mutation occurs, every cell in the developing embryo will carry the mutation

Answer 9

True

Question 10

What signals DNA uracil glycosylase enzyme to cleave the uracil from the sugar DNA backbone? (during base excision)

Answer 10

The actual presence of uracil

Question 11

What signals AP endonuclease to cleave the backbone on either side of the area that lacks a base during base excision? (during base excision)

Answer 11

The lack of a nitrogenous base on the bare deoxyribose sugar (after the uracil is cleaved off)

Question 12

During nucleotide excision, what signalizes enzymes to cleave the DNA backbone on either side of the mismatched bases?

Answer 12

The damaged bases themselves

Question 13

While mutations can provide the basis for genetic variability, it is the _____ of DNA replication that retains point mutations

Answer 13

Fidelity

Question 14

Silent mutations are largely due to __________ (more than one word)

Answer 14

The redundant nature of the genetic code

Question 15

What mutation is the cause of the disease cystic fibrosis? (name mutation and location of it)

Answer 15

The deletion of three nucleotides in the protein coding region of a chloride channel called the CFTR transporter

Question 16

What effect does the mutation have on the CFTR transporter?

Answer 16

Causes it to become unstable

Is largely degraded prior to being able to reach the cell membrane (where it should embed to facilitate chloride ion transport)

Question 17

True or false: DNA ligases that are involved with DNA replication are also involved in DNA repair of single-stranded breaks

Answer 17

False

They’re two diff kinds of DNA ligase

Question 18

True or false: small inversions are common in large populations

Answer 18

True

Question 19

What mutation explains how the order of genes in closely related species can vary?

Answer 19

Inversion mutation