CK L1 mutation and mutagenesis

Question 1

a mutation is…?

a mutation is also…?

Answer 1

a heritable alteration in a gene or chromosome
(a change in the sequence of nucleotides)

the process that produces the alteration (the source of most alleles)

Question 2

Mutagenesis is…?

Answer 2

the process of mutation generation

Question 3

DNA integrity (two types of stand damage)

Answer 3

single strand damage

double strand damage

Question 4

what components of DNA can be altered / damaged?

Answer 4

all components

e.g bases, strandsva

Question 5

what exogenous sources can cause DNA damage?

Answer 5

> ionising radiation
> free radicals
> UV radiation
> matagenic chemicals
> Anti-cancer drugs

Question 6

what endogenous sources can cause DNA damage?

Answer 6

> replication errors
free radicals
transposons (elements of DNA that can move around

Question 7

Exogenous source - Types of Ionising radiation

Answer 7

> X-Ray
alpha and beta particles
Gamma rays

Question 8

Exo & Endogenous sources - types of free radicals

Answer 8

UV light
Smoking
Air pollution
Inflammation 
Metabolism

Question 9

Exogenous sources- types of UV radiation

Answer 9

> indirect damage via free radicals

> direct damage causes pyrimidine dimers (CPDs)

Question 10

Exogenous sources - type if mutagenic agents

Answer 10

alkylating agents
intercalating agents
Anti-cancer drugs

Question 11

Exogenous sources - mutagenic agent alkylating agent information

Answer 11

> very powerful
addition of alkyl group to DNA base
induces mispairing at DNA replication
leads to base substitutions

Question 12

Exogenous sources - mutagenic agent intercalating agent information

Answer 12

> intercalate between bp of dsDNA
induces single nucleotide addition/deletion
leads to frameshift mutations

Question 13

Exogenous sources - mutagenic agent Anti-cancer drugs information

Answer 13

> used to induce cell death
blocks resolution of Top1-DNA adducts
causes persistent single strand breaks
can causes double strand breaks

Question 14

Endogenous sources- DNA replication errors information

Answer 14

types-
> mismatches
> insertions
> deletions

Question 15

how much DNA damage happens per day…?

Answer 15

1 x 10 to the 6 molecular lesions per cell per days

Question 16

Endogenous sources- Transposons information

Answer 16

> specific DNA sequences (>1 gene)
supernumerary (many copies)
always contained within other DNA molecules
move around (transpose) as a discrete unit
move around (transpose) to random sites
ubiquitous
may insertionally inactive genes or change gene expression

Question 17

what will happen if…?

1) a transposon jumps in the gene
2) a transposon jumps outside the gene

Answer 17

1) it will activate it

2) it will have no effect

Question 18

what is site-directed mutageneis?

Answer 18

mutations can be made deliberately