Gene Mutations

Question 0

base substitutions

• transitions (A changes to T) (G changes to C)
• transversions (A changes to G) (G changes to T)

Answer 0

point mutations

Question 1

molecular changes to the DNA sequence

Answer 1

gene mutations

Question 2

loss or removal of nucleotides

Answer 2

deletions

Question 3

addition of nucleotides

Answer 3

insertions

Question 4

mutations can alter function of DNA

-promoters, enchancers, terminators, boxes, element could be rendered _____________

Answer 4

dysfunctional

Question 5

mutations can alter function of RNA

• changes in primary structure lead to changes in ____________ _______
• __________ removal via splicing may not occur

Answer 5

secondary structure

introns

Question 6

mutations can alter function of proteins

• ________ ______ sequences can be altered
• affect secondary- tertiary structure, __________ ________

Answer 6

active sites

Question 7

don’t alter RNA or protein secondary structure

Answer 7

silent mutations

Question 8

amino acid changes during coding mutations affecting expression

Answer 8

missense mutations

Question 9

coding region mutations affect expression.. changes stop codon or inserts a stop codon

Answer 9

nonsense mutations

Question 10

coding region mutations that affect expression and changes reading frame, typically due to indel

Answer 10

frameshift mutations

Question 11

________ _____ allele due to coding region point mutation

Answer 11

sickle cell

Question 12

promoter mutation that results in up or down regulation

Answer 12

up/down promoter mutations

Question 13

may alter translation of mRNA

Answer 13

5’/3’ untranslated region mutations

Question 14

may affect gene regulation

Answer 14

regulatory element/operator mutations

Question 15

may affect proper splicing of pre-mRNA

Answer 15

splice recognition site mutation

Question 16

NEUTRAL mutations:
neutral vs selected
can be dependent upon ____________, no change in functions

Answer 16

environment

Question 17

mutation causes mutant to become wild type

Answer 17

reversion

Question 18

decreases fitness

Answer 18

deleterious mutation

Question 19

enhances fitness

Answer 19

beneficial mutation

Question 20

mutant phenotype expressed in some, but not all situations

Answer 20

conditional mutants

Question 21

translocation to heterochromatic chromosome

Answer 21

position effect

Question 22

changes in DNA structure due to bio molecular processes

Answer 22

spontaneous mutations

Question 23

causes by environmental agents

Answer 23

induced mutations

Question 24

recombinations
-indels, translocations, inversions
segregation
- aneuploidy, polyploidy 
DNA replication
- point mutations
transposable elements (jumping genes)
- insertion into the sequence of a gene

Answer 24

spontaneous mutations

Question 25

cytosine deaminates to create uracil or thymine

Answer 25

deamination

Question 26

temporary changes in base structure immediately prior to replication

Answer 26

tautomeric shifts

Question 27

metabolism results in reactive oxygen species (ROS)

• hydrogen peroxide, superoxide, etc
• damage DNA, proteins, lipids
• counteracted by antioxidants

Answer 27

mutation due to oxidative stress

Question 28

likelihood that a gene of base will be altered by a new mutation

Answer 28

10^-5 to 10^-9 per gene, per cell, per generation

humans: 100-200 mutations per generation

Question 29

mutation rates are _________ variable from species to species

Answer 29

variable

Question 30

mutation frequency

• not mutation _______
• # mutants/ total population

Answer 30

rate