Meiosis Flashcards
1
Q
what is the first meiosis process do
A
- separates Homologous chromosomes
2
Q
what are the 4 stages in meiosis 1
A
- Prophase 1
- Metaphase 1
- Anaphase 1
- Telophase 1 and cytokinesis
3
Q
describes what happens in Prophase 1
A
- homologous chromosomes align and synapse
- crossing over between non-sister chromatids occurs at chiasmata
- crossing-over results in chromatids now being a mix of pieces from each homologous chromosome
4
Q
describe what happens in Metaphase 1
A
- paired homologous chromosomes move to metaphase plate
- chiasmata line up on metaphase plate
5
Q
describe what happens in Anaphase 1
A
- recombined homologous chromosomes separate (disjoin)
- sister chromatids remain attached
6
Q
describe what happens in Telophase 1 and cytokinesis
A
- Haploid cells with duplicated chromosomes (the pairs of sister chromatids) form
- haploid because only half the genetic information is in each new cell
7
Q
what is the second meiosis process do
A
- separates sister chromatids
8
Q
what happens during meiosis 2
A
goes through the same process as meiosis 1 to separate the sister chromatids
9
Q
what are the 2 main reasons to have sex
A
- sexual reproduction produces genetic diversity
- genetic diversity allows selective responses
10
Q
how does sexual reproduction produce genetic diversity through
A
- independent assortment of chromosomes
- crossing over
- random fertilisation
11
Q
what are examples of genetic diversity that allows selective responses
A
- spatially variable environments
- changing environments
- sib-sib competitions
12
Q
what is independent assortment
A
- is the process where chromosomes move randomly to separate poles during meiosis
