Paper 1 - Meiosis Flashcards
1
Q
What is meiosis ?
A
Produces four daughter cells, each with half the number of chromosomes than the original - genetically different haploid gametes.
2
Q
What happens during meiosis ?
A
- Each chromosome relicates - copies stay attached- looks like an ‘X’
- two sets of chromosomes pair up - 23 pairs
- pairs separate into two new cells (first division)
- copies now separate - ‘X’ splits into two new cells (second division)
- Each daughter cell has 23 chromosomes (haploid)
3
Q
How can we establish a pair of chromosomes during fertilisation ?
A
One set + one set = one pair
4
Q
Why do gametes need to be haploid ?
A
If two diploid joined the zygote would have 4 sets of chromosomes
