Meiosis 2

Question 1

Prophase 2

Answer 1

• nuclear membrane disappears
  -centrioles transform back to asters
  -spindle fibers reappear.
  -n=2

Question 2

Is there an interphase between meiosis 1 and meiosis 2?

Answer 2

No. there’s a preparatory phase between the 2 divisions called interkinesis

Question 3

metaphase 2

Answer 3

each single chr line up randomly to form the equatorial plate
n=2

Question 4

anaphase 2

Answer 4

-separation and migration of the condensed chrs each to the opposite poles of the cell
- centromeres are also divided
n=2

Question 5

schematize anaphase 2

Question 6

telophase 2

Answer 6

-the cytoplasm/ cell membrane of the 2 daughter cells undergo cytokinesis leading to 4 haploid cells /gametes of n chrs of 1 chromatin.
-cell membrane starts to reappear
-asters transform back to centrioles/centrosomes.
-chrs deconsecrated back to chromatins.
n=2

Question 7

how do we calculate the number of different gametes?

Answer 7

number of games = 2 power n
n; nb of pairs of chrs.

Question 8

why is meiosis important?

Answer 8

because:
- it creates genetic differentiation due to: crossing over (Prophase 1), chrs alignment (metaphase 1), random separation of chrs (A1) and sister chromatids (A2)

• regulatory factor to restore normal nb of chrs (46)

Question 9

is there a DNA replication during meiosis?

Answer 9

no, only in interphase (S phase)