unit 4, gene/chromosome mutation Flashcards
1
Q
what is a gene mutation? when does it occur?
A
- change in base sequence of dna
-dna repication
2
Q
how does gene mutation occur?
A
- when exposed to mutogenic agents, eg) high energy raditation, ionising radiation
- exposed to chemicals, eg) cigarette
3
Q
what is the result of gene mutation?
A
deletion of base
substitution of base
4
Q
why does substitioion of base sometime not work?
A
due to the degnerate code
5
Q
why is deletion more harmful than substitution?
A
due to frameshift, new triplet codes are made , so amino acids will be incorrectly coded for
6
Q
what is chromosome mutation?
A
the chromosome or chromatid do not euqally split in anaphase, this is called non disjunction
7
Q
what is polyploidy?
A
- change in the whole set of chromosomes
- all chromsomes fail to pull apart in anaphase equally
8
Q
what is aneuploidy?
A
- changes in INDIVIDIUAL chromsomes, they are unable to pull apart in anaphase equally
