Meiosis

Question 1

What is meiosis?

Answer 1

Meiosis is the process by which a cell divides into two gametes for the purpose of sexual reproduction

Question 2

Who does meiosis?

Answer 2

Male (XY) + Female (XX) = Zygote → Foetus

Question 3

Why does meiosis occur?

Answer 3

To form a baby which will eventually grow and develop into an adult after the process of mitosis

Question 4

Where does meiosis occur?

Answer 4

Sexual Cells = Testicle (Male) + Ovary (Female)

Question 5

When does meiosis occur?

Answer 5

Over 28 day cycle

Question 6

What is produced in the testis?

Answer 6

Sperm (Spermatocyte)

Question 7

What is produced in the ovaries?

Answer 7

Eggs / Ova (Oocyte)

Question 8

How many chromosomes are in the sperm and egg?

Answer 8

23 each (haploid cells / n)

Question 9

How many chromosomes are in the sperm and egg after fertilisation?

Answer 9

46 altogether (diploid cells / 2n)

Question 10

How does meiosis occur?

Answer 10

Meiosis I and II

Question 11

Give 9 processes of meiosis

Answer 11

1) Interphase – DNA replicates to create four pairs of homologous chromosomes with two chromatids
2) Prophase I – Chromosomes in the parent nucleus are copied, then condense and crossover and nuclear membrane breaks down
3) Metaphase I – Homologous pairs line up at the equator, a spindle forms attaching to centromeres and genetic material is swapped
4) Anaphase I – Homologous pairs are separated and pulled apart from opposite poles of the cell
5) Telophase I & Cytokinesis – Nuclei reform and the cell divides into two
6) Prophase II – New spindle forms around the chromosomes
7) Metaphase II – Chromosomes line up at the equator
8) Anaphase II – Chromatids are separated and pulled apart to opposite poles of the cell
9) Telophase II & Cytokinesis – Nuclei reform and the cell divides into four, forming unique combinations of original chromosome pairs