Ch12 | Mutation

Question 0

A mutation only becomes stable and heritable when…

Answer 0

(1) It occurs within germ line (gametic)
(2) Is duplicated
(3) Is base-paired appropriatel

Question 1

Mutation

Answer 1

Change in DNA sequence

Question 2

Point mutation

Answer 2

Change in a single base pair

Question 3

Transition

Answer 3

Purine to Purine or Pyrimidine to Pyrimidine

Question 4

Transversion

Answer 4

Purine to Pyrimidine or vice-versa

Question 5

Silent mutation

Answer 5

When the mutation results in coding for same amino acid (synonymous codon)

Question 6

Missense mutation

Answer 6

Change in codon resulting in different amino acid

Question 7

Nonsense mutation

Answer 7

Change that no longer codes for amino acid and instead terminates or stops translation

Question 8

Steps (2) of Point Mutation

Answer 8

(1) DNA Polymerase places incorrect nucleotide

(2) Repair fails to occur and base-pairing occurs

Question 9

Evolution due to mutation…

Answer 9

(1) Requires selective advantage

(2) Is rare

Question 10

In drosophila, how often were mutations found to be deleterious?

Answer 10

~70% of the time

Question 11

Oncogenes

Answer 11

Code for proteins that drive cell division cycle

Question 12

Tumor suppressor genes

Answer 12

Code for proteins that suppress cell division

Question 13

Insertion

Answer 13

Addition of one or more codons to wild-type sequence

Question 14

Deletion

Answer 14

Loss of one or more nucleotides from wild-type sequence

Question 15

Indels

Answer 15

Category including insertions and deletions

Question 16

Reading frame

Answer 16

DNA sequence from start codon to stop codon

Question 17

Frameshift

Answer 17

Change in reading frame due to one or two indels, because codons are read in triplets

Question 18

What is the typical result of a frameshift mutation?

Answer 18

Truncated protein

Question 19

Triplet expansion disease

Answer 19

Potential result of insertion of three novel nucleotides (codon triplet)

Question 20

Polyglutamine (PolyQ) diseases

Answer 20

The majority of triplet expansion diseases, involving CAG insertion, such as Huntington’s chorea

Question 21

Duplication mutation

Answer 21

Amplification of large tract of DNA leading to increased dosage effect

Question 22

Inversion mutation

Answer 22

Result of inversion of large tract of DNA sequence

Question 23

Translocation mutation

Answer 23

Exchange of DNA between non-homologous chromosomes

Question 24

Fusion gene

Answer 24

When a mutation results in hybridization of two different genes

Question 25

Why is water a key contributor to mutation?

Answer 25

It is the universal intracellular solvent

Question 26

Why is DNA vulnerable to alkylation and oxygen-reactive agent?

Answer 26

The high degree of negative charge along its backbone

Question 27

Deamination

Answer 27

Removal of amino group from molecule or compound

Question 28

Hydrolytic attack

Answer 28

Primary weakness of any amino group containing complex

Question 29

Which three (3) nucleotides contain an amino group?

Answer 29

(1) C (2) A (3) G

Question 30

What is the most common deamination in nucleotides and what is the result?

Answer 30

Cytosine deamination results in Uracil (100X more common)

Question 31

Why is deamination of adenine or guanine different in their outcome when compared to cytosine?

Answer 31

The resulting base pairs are not normally found in nucleotides and are likely to be deleterious

Question 32

CpG sequence

Answer 32

Methylation of C residue followed by G

Question 33

Abasic site

Answer 33

Loci missing nucleotide base

Question 34

Depurination

Answer 34

Hydrolysis of N-B-gylcosyl bond on a purine

Question 35

Alkylation

Answer 35

Addition of alkyl group to nucleotide

Question 36

Carcinogen

Answer 36

Any substance directly causing cancer

Question 37

Genotoxic

Answer 37

DNA-reactive compounds

Question 38

Cytotoxic

Answer 38

Mutagen with lethal result

Question 39

Ames test

Answer 39

Standard for mutagen identification

Question 40

Auxotroph

Answer 40

Organism unable to synthesize all of its own organic compounds necessary for survival

Question 41

Reversion mutation

Answer 41

Mutation that undoes previous mutation

Question 42

Pyrimidine dimer

Answer 42

UV induced cross-link binds between a pair of pyrimidines

Question 43

Mismatch Repair

Answer 43

Repair due to errors in replication process

Question 44

Dam methylase

Answer 44

Enzyme that provides strand discrimination in bacteria

Question 45

DNA photolyase

Answer 45

Enzyme of direct repair driven by photo-reactive energy mechanism

Question 46

Two (2) types of excision repair

Answer 46

(1) Base | (2) Nucleotide

Question 47

DNA glycosylase

Answer 47

Recognizes point of base excision repair

Question 48

AP endonuclease

Answer 48

Cleaves abasic site during base repair in preparation for placement of new base

Question 49

Nucleotide Excision Repair

Answer 49

Removal and replacement of larger, damaged sequence segments along with adjacent DNA

Question 50

How are DNA lesions likely to be removed and replaced?

Answer 50

Nucleotide excision repair

Question 51

Transcription-coupled repair

Answer 51

Use of NER by eukaryotes to target stalled RNA polymerase on a damaged nucleotide

Question 52

Translesion synthesis

Answer 52

Use of a bypass polymerase to overcome obstructive lesion