3.4 Genetic variation during mutations Flashcards
1
Q
What is a mutation ?
A
An alteration to the DNA base sequence
2
Q
What is a substitution mutation ?
A
Where a nucleotide in the DNA base sequence is replaced by another
3
Q
What is a deletion mutation ?
A
When a nucleotide in the DNA base sequence Is lost, more likely to be harmful as frameshift occurs
4
Q
What is a mutagenic agent and give examples ?
A
Factors that increase the chance of mutation such as UV light and certain chemicals
5
Q
What is chromosome non-disjunction ?
A
When a chromosome fails to separate correctly during meiosis, this results in gametes with one more or one less chromosome than normal
6
Q
How many daughter cells are produced during meiosis ?
A
4 haploid cells with half genetic information
7
Q
In what two ways does meiosis cause genetic variation ?
A
- Crossing over
- Independant segregation
Both result in new combinations of alleles
