Biology 180: Meiosis Flashcards
(11 cards)
Process of Meiosis
1 diploid cell -> 4 un-identical haploid cells
- Interphase
Meiosis I - Reduction Division, 1 diploid cell -> 2 haploid cells
Homologous chromosomes seperate, chromosome number is halved
2. Prophase I
3. Metaphase I
4. Anaphase I
5. Telophase I
6. Cytokinesis
Meiosis II 2 haploid cells -> 4 un-identical haploid cells
- Sister chromatids separate and each daughter cell divides in two
- very similar to mitosis
7. Prophase II
8. Metaphse II
9. Anaphase II
10. Telophase II
11. Cytokinesis
Interphase for Meiosis I
Chromosome replication occurs so each chromosome consists of a pair of sister chromatids
Prophase I
homologous chromosomes come together (synapse) to form pairs. Crossing over occurs. The nuclear envelope breaks down. The spindle apparatus forms and attaches to the chromosomes
homolog synapse
Metaphase I
homologous pairs of replicated chromosomes line up along the equator because the spindle apparatus puts them there
Anaphase I
- homologs separate; memebers of each homologous pair go to opposite poles
- sister chromatids do not separate
Telophase I/Cytokinesis for Meiosis I
- the chromosomes finish moving to opposite poles
- spindle fibers disappear
- cytoplasm divides to form 2 haploid daughter cells
Prophase II
A new spiblde apparatus forms, a spindle fiber attaches to each chromosome, and chromosomes begin to move toward the metaphase plate
Metaphase II
Chromosomes line up along the metaphase plate
Anaphase II
Sister chromatids seperate to form individual chromosomes; spindle fibers pull the chromosomes to opposite poles of the cell
Telophase II
chromosomes finish migrating to opposite poles of the cell and nuclear envelopes form
Cytokinesis for Meiosis II
the cell divides along its midline to form two daughter cells, resulting in a total of four daughter cells from the original single cell
