8b. Mitosis and Cancer

Question 1

How many chromosomes do humans have

Answer 1

23 Homologous pairs

Question 2

What is the diploid number

Answer 2

The total number of chromosomes is a normal body cell
e.g 46

Question 3

What happens prior to cell devision

Answer 3

DNA in the chromosomes replicate all the way along its length and each chromosome becomes two threads called chromatids
Held together at the centromeres

Question 4

What is a chromosome

Answer 4

Long, linear structures consisting of DNA and histone proteins

Question 5

What is a homologous chromosome

Answer 5

A pair of chromosomes containing the same genes in the same positions, each derived origionally to form a different parents gamete at fertilisation

Question 6

What is a chromotid

Answer 6

One of the two threads of a chromosomes, formed after DNA replication. Each chromatid in a chromosome is an exact replica of the other

Question 7

What happens in mitosis

Answer 7

A parent cell divides to produce two daughter cells
-It increases thr number of cells during growth
-It replaces tissue during repair
-Allows asexual reproducton which produces fertile offspring which ar egenetically identical to parent

Question 8

What is the only way that variation can arise when a cell divides by mitosis

Answer 8

Mutation