Meiosis

Question 1

What is the differences between mitosis and meiosis

Answer 1

Meiosis

• Only in gametes
• Recombination of genetic material (generates diversity)
• Two cell divisions
• 4 haploid daughter cells

Question 2

Chromosomes condense

Answer 2

Prophase 1

Question 3

Chromosomes pair up - aligns with the homologue partner. Pair up at the corresponding positions along their full length

Answer 3

Prophase 1

Question 4

Crossing over. Helped by synaptonemal complex

Answer 4

Prophase 1

Question 5

Homologue pairs (not individual chromosomes) line at the plate

Answer 5

Metaphase 1

Question 6

Each chromosome attaches to microtubules from just one pole of the spindle

Orientation is random

Answer 6

Metaphase 1

Question 7

Sister chromatids for each chromosome remain attached

Answer 7

Anaphase 1

Question 8

Homologues pull apart

Answer 8

Anaphase 1

Question 9

Chromosomes arrive at the end of poles

Answer 9

Telophase 1

Question 10

Cytokinesis usually occurs now - forming two daughter haploid cells

Answer 10

Telophase 1

Question 11

What is the separation which occurs during meiosis 1

Answer 11

Homologous pairs separate

Question 12

What is the separation which occurs during meiosis 2

Answer 12

Sister chromatids separate

Remember this happens twice as meiosis has produced two cells

Question 13

Centrosome move apart, spindle forms, spindle microtubules begin to capture chromosomes

Answer 13

Prophase 2

Question 14

Two sister chromatids of each chromosome are captured by microtubules from opposite spindle poles

Answer 14

Prophase 2

Question 15

Chromosomes line up individually along the metaphase plate

Answer 15

Metaphase 2

Question 16

Sister chromatids separate and are pulled towards opposite poles of the cell

Answer 16

Anaphase 2

Question 17

Nuclear membranes form around each set of chromosomes

Answer 17

Telophase 2

Question 18

Chromosomes decondense

Answer 18

Telophase 2

Question 19

Cytokinesis splits the chromosomes into two new cells

Answer 19

Telophase 2

Question 20

What are the two ways meiosis creates genetic differences

Answer 20

1. Crossing over (prophase 1)
2. Random orientation of homologue pairs (anaphase 1)

Question 21

How many round of mitosis must a primordial germ cell go through to become oogonia

Answer 21

30

Question 22

When does oogonia enter prophase 1

Answer 22

By 8th month of intrauterine life

Question 23

When in meiosis 1 completed in a female

Answer 23

At ovulation

Question 24

When is meiosis 2 completed in a female

Answer 24

If fertilisation occurs

Question 25

What is non-disjunction

Answer 25

Failure of chromosome pairs to separate in meiosis 1 or sister chromatids to sperate properly in meiosis 2