10. Cell Division

Question 1

What happens in G1?

Answer 1

Growth and preparation for division

Replicate key components

Question 2

What happens in S phase?

Answer 2

DNA replication

Question 3

What happens in G2?

Answer 3

Resting phase

Check for errors and repairs

Question 4

What happens in prophase?

Answer 4

Chromatin contracts
Nuclear membrane breaks down
Start of spindle fibres

Question 5

What happens in metaphase?

Answer 5

Chromosomes line up along cell’s centre

Spindle fibres attach to each centromere

Question 6

What happens in anaphase?

Answer 6

Spindle fibres contract

Centromeres break and chromosomes pulled apart

Question 7

What happens in telophase?

Answer 7

Chromosomes revert back to chromatin

Cleavage furrow forms between 2 cells

Question 8

What is a centrosome?

Answer 8

Microtubule organising centre

Question 9

What happens when a chromosome lacks a centromere?

Answer 9

Not attached to spindle fibre

Chromosome isn’t passed on

Question 10

Give the steps in meiosis

Answer 10

1. Chromosomes duplicate
2. Homologous chromosomes pair up and exchange segments
3. Tetrads line up and attach to spindle fibres
4. Pairs of homologous chromosomes are pulled apart
5. Cell division occurs again to produce 4 haploid cells

Question 11

How is genetic diversity introduced in meiosis?

Answer 11

Recombination and independent assortment

Question 12

What is a chiasmata?

Answer 12

Holds similar chromosomes together until formation of spindle