pre exam 2 Flashcards

You may prefer our related Brainscape-certified flashcards:
1
Q

mutagens

A

physical or chemical agents that can cause mutations

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

average mutation rate in humans

A

2.5 x 10^-8 mutations per nucleotide (175 mutations per diploid genome per generation)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

types of point mutations

A

base-pair substitutions - replaces one nucleotide and its partner with another pair of nucleotides

insertion or deletions - additions or losses of nucleotide pairs in a gene
*more severe effect!

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

types of base-pair substitutions

A

silent mutations - no effect on amino acid because of redundancy in genetic code

missense mutations - still code for an amino acid, but not necessarily the right amino acid

nonsense mutations - change codon into stop codon, nearly always leading to a nonfunctional protein

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

info on insertions/deletions

A
  • can have a disastrous effect on protein
  • may alter the reading frame, producing a frameshift mutation
  • can occur during DNA replication, recombination, or repair
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what are the effects of DNA damage and mutations?

A
  • developmental abnormalities
  • senescence
  • apoptosis
  • tumors
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

emergence of a variant in a population

A
  • pop. initially dominated by one form of virus
  • random variants exist at low levels or develop spontaneously
  • variant gains competitive advantage due to natural selection (can coexist with initial form or become dominant)
  • new variants can continue to emerge
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

consequences of new gene variants

A
  • variant may spread more quickly, cause more severe disease, and may be more deadly
  • virus may evade diagnostic tests
  • variants may be more resistant or immune to therapies
  • may gain ability to escape recognition by immune system, making vaccines and natural immunity not effective
How well did you know this?
1
Not at all
2
3
4
5
Perfectly