1.1

Question 1

What is a somatic cell

Answer 1

Any cell in the body other than cells involved with reproduction (Sperm and ova the cells that divide to make them)

Question 2

How do somatic cells divide

Answer 2

Mitosis to form more somatic (diploid cells)

Question 3

What is a germline cell

Answer 3

Gametes and the cells that divide to make them

Question 4

How do germline cells divide

Answer 4

Mitosis (diploid) AND meiosis (haploid)

Question 5

How many PAIRS of chromosomes does a diploid cell have

Answer 5

23

Question 6

Why do germline cells divide by mitosis

Answer 6

They divide by mitosis to maintain the diploid chromosome number and make more germline cells.

Question 7

Why do germline cells divide by meiosis and how

Answer 7

They can divide by meiosis to make gamete cells. They undergo 2 divisions:
Firstly separating homologous chromosomes.
Secondly separating chromatids.
4 daughter cells are produced that are all haploid.

Question 8

How many SINGLE chromosomes does a gamete cell have

Answer 8

23

Question 9

What is differentiation

Answer 9

When an unspecialised cell changes into a specialised cell.
The cell expresses certain genes to produce proteins characteristic for that type of cell

Question 10

What type of stem cells are multipotent

Answer 10

Tissue stem cells as they can only differentiate into the types of cell found in a particular tissue
E.G blood stem cells can only change into white blood cells (phagocytes, lymphocytes) or red blood cells, platelets

Question 11

What type of stem cells are pluripotent

Answer 11

Embryonic stem cells as all the genes in embryonic stem cells can be expressed so they can differentiate into any type of cell

Question 12

Why do we have Tissue stem cells

Answer 12

They are involved in growth, repair and renewal of cells found that particular tissue

Question 13

What are therapeutic uses of stem cells

Answer 13

Stem cells are involved in growth and repair of damaged organs and tissues NOT CELLS
E.G corneal repair in the eye, regeneration of damaged skin

Question 14

What are research uses of stem cells

Answer 14

Provide info on cell processes like cell growth, differentiation and gene regulation.
To study how diseases develop
For drug testing by using stem cells as model cells to test drugs on

Question 15

What’s the ethical reason for using embryonic stem cells

Answer 15

They can offer treatments for disease and injuries

Question 16

What’s the ethical reason against using embryonic stem cells

Answer 16

involves destruction of embryos

Question 17

How do cancer cells form

Answer 17

Cells do not respond to regulatory signals so they excessively divide

Question 18

What is meant by tumour

Answer 18

When the cells divide excessively to produce a mass of abnormal cells

Question 19

What is meant by secondary tumour and how does it happen

Answer 19

Cells within the tumour may fail to attach to eachother and spread throughout the body where they form secondary tumours