DNA Damage and Mutation

Question 1

Define mutation:

Answer 1

A heritable change in the DNA sequence

Question 2

Most mutations are spontaneous / occur in response to the environment

Answer 2

Are spontaneous

Question 3

All mutations are harmful: True / False

Answer 3

False

Question 4

(Causes of Mutations)
Cause 1:

Answer 4

Replication errors made by DNA polymerase that are not corrected

Question 5

(Causes of Mutations)
Cause 2:

Answer 5

DNA damage that is not corrected

Question 6

(Causes of Mutations)
Why is DNA damage or errors different from a mutation?

Answer 6

DNA damage and errors could still be corrected, but a mutation is permanent change to the sequence

Question 7

(Causes of Mutations)
What needs to happen to result in a mutation?

Answer 7

DNA replication of the damaged DNA or DNA with a replication error

Question 8

Mutagen | Type of damage caused by |the mutagen
—————————————————- UV |

Answer 8

Cross-linked thymine bases

Question 9

Mutagen | Type of damage caused by the mutagen
—————————————————– X-rays |

Answer 9

Double-strand breaks in the DNA

Question 10

Chemicals|
in tobacco|
smoke |

Answer 10

Bulky side groups added to bases

Question 11

(Type of Mutation in Protein-Coding Region)
Synonymous substitution:

Answer 11

A substitution that does not change the amino acid

Question 12

(Type of Mutation in Protein-Coding Region)
Missense substitution:

Answer 12

A substitution that changes the amino acid

Question 13

(Type of Mutation in Protein-Coding Region)
Nonsense substitution:

Answer 13

A substitution that creates a stop codon

Question 14

(Type of Mutation in Protein-Coding Region)
Insertion/deletion (indel) that causes a frameshift:

Answer 14

Insertion or deletion that disrupts the reading frame (+/- a number of bp that is not a multiple of 3)

Question 15

(Type of Mutation in Protein-Coding Region)
Insertion/deletion (indel) that does not cause a frameshift:

Answer 15

Insertion or deletion that does not disrupt the reading frame (+/- a number of bp that is a multiple of 3)

Question 16

(Large Scale DNA Damage)
Give an example of large-scale DNA damage:

Answer 16

Double-stranded break in a chromosome

Question 17

(Large Scale DNA Damage)
What is one cause of large-scale DNA damage?

Answer 17

X-rays

Question 18

(Large Scale DNA Damage)
How can this type of damage alter the genetic information of a cell?

Answer 18

If not repaired, genetic information on the chromosome portion without the centromere can be lost when the cell
divides

Question 19

Though mutations can arise from errors in DNA replication, 99% of the errors during replication are corrected by the proofreading activity of the enzyme _______.

Answer 19

DNA polymerase