lecture 14 - meiosis

Question 1

What are the phases in meiosis.

Answer 1

Meiosis 1: prophase I, metaphase I, anaphase I, telophase & cytokinesis I
Meiosis 2: same

Question 2

What are the key differences in mitosis and meiosis I.

Answer 2

in meiosis I

• homologous chromosomes synapse
• chiasmata is on metaphase plate (rather than centromeres)
• chromosomes disjoin (rather than chromatids)
• 2n to n (rather than 2n to 2n)

Question 3

What three things sexual reproduction produces genetic diversity through.

Answer 3

• independent assortment
• crossing over
• random fertilisation of gametes

Question 4

At what phase does crossing over occur.

Answer 4

prophase 1

Question 5

What is the difference between a haploid and diploid cell

Answer 5

haploid n

diploid 2n

Question 6

Give the number of chromosomes in a human sperm.

Answer 6

23

Question 7

Give the number of chromosomes in a human skin cell.

Answer 7

46

Question 8

Indicate the number of chromosomes in the cells at each stage of meiosis (n=23)(2n=46)

Answer 8

meiosis I: 2n to n

meiosis II: splits the two n’s in the cell to one n in each cell

Question 9

At the end of meiosis I are the daughter cells diploid or haploid?

Answer 9

haploid

Question 10

Are the cells genetically identical at the end of meiosis 1?

Answer 10

no

Question 11

At the end of meiosis II are the daughter cells diploid or haploid?

Answer 11

haploid

Question 12

How many cell are produced at the end of meiosis II.

Answer 12

4