2.6 Meiosis Flashcards
1
Q
meiosis
A
- Reduction division
- Produces Gametes
- Haploid
- Genetically unidentical
- 23 chromosomes
- Sexual reproduction
2
Q
Meiosis i
A
- Prophase 1
3
Q
Prophase i
A
- Chromosomes condense
- Homologous chromosomes pair up to form a homologous pair
- Non-sister chromatids wrap around each other at chiasmata
- Crossing over occurs
- Nucleolus disappears
- Nuclear envelope disintegrates
- Spindles form
4
Q
Crossing over of chromatids
A
- Each of the four daughter cells formed from meiosis contains chromatids with different alleles
- Chromosomes of homologous pairs come together
- Prophase 1- chromatids cross over
- One
5
Q
Crossing over of chromatids in Prophase i
A
- Homologous pairs of chromosomes come together and pair up
- The chromatids twist around each other and bits of chromatids swap over
- Chromatids still contain the same genes but now have a different combination of alleles
6
Q
Metaphase i
A
- Homologous pair line up across equator
- Homologous pair arranged randomly in random assortment
- Spindles attach to centromeres
7
Q
Anaphase i
A
- 1 chromosome in each pair is pulled to opposite poles
8
Q
Telophase i
A
- Two new nuclear envelopes form
- Cytokinesis
9
Q
Meiosis ii
A
- Very similar it mitosis
- Metaphase ii- random assortment
- Anaphase ii- random segregation
10
Q
Prophase ii
A
- If nuclear envelope has reformed, then it breaks down
- Chromosomes condense
- Spindles form
11
Q
Metaphase ii
A
- Chromosomes attach to equator of spindle
- Chromatids of each chromosome are randomly arranged
12
Q
Anaphase ii
A
- Centromeres divide
- Chromatids pulled to opposite poles of spindle
- Chromatids are randomly segregated
13
Q
Telophase ii
A
- Nuclear envelope form around each of the 4 haploid nuclei
- In animals. the 2 cells now divide to give 4 haploid cells
- In plants, a tetrad of 4 haploid cells is formed
