Meiosis

Question 1

What is meiosis?

Answer 1

nucleus divides twice to provide 4 daughter cells.

each gamete contains half the number of the chromosomes of the parent cell - haploid

Question 2

Meiosis I?

Answer 2

First division, pair of homologous chromosomes are separated into two cells. each intermediate cell will only contain one full sets of genes, instead of two, so the cells are haploid

Question 3

meiosis 2?

Answer 3

pairs of chromatids present in each cell are separated , forming two more CLS, four haploid daughter cells produced

Question 4

Prophase 1

Answer 4

• Chromosomes condense, nuclear envelope disintegrate, nucleolus disappears and spindle formation begins .
• homologous chromosomes pair up, forming bivalents. Chromosomes are large molecules of DNA, moving them through cytoplasm causes chromatids to tangle.

Question 5

Metaphase 1?

Answer 5

homologous pairs of chromosomes assemble along the metaphase plate, orientation is random. Independent assortment in metaphase 1 results in genetic variation

Question 6

Anaphase 1?

Answer 6

-Homologous chromosomes are pulled to opposite poles, chromatids stay joined.
-sections of DNA which were crossed over , break off and rejoin.
point at which chromatids break and join is called Chiastama.
-When exchange occurs, this recombinat chromatids, genes being exchanged between chromatids

Question 7

Telophase 1?

Answer 7

chromosomes assemble at each pole and the nuclear membrane reforms. chromosomes uncoil.
cell undergoes cytokinesis, dividing into two cells

Question 8

Prophase 2?

Answer 8

chromosomes which still consist of two chromatids condense and become visible again. Nuclear envelope breaks down, spindle formation begins.

Question 9

Metaphase 2?

Answer 9

Individual chromosomes assemble at the metaphase plate.
due to crossing over, chromatids are no longer identical so there is Independent assortment again, more genetic variation.

Question 10

Anaphase?

Answer 10

results of the chromatids of individual chromosomes being pulled to opposite poles after division on the centromeres.

Question 11

Telophase 2?

Answer 11

chromatids assemble at the poles. chromosomes uncoil and form chromatin again, nuclear envelope reforms and nucleus becomes visible