Unit 1 (K1) - Differentiation/Division

Question 1

What are somatic cells?

Answer 1

Any cell in the body other than cells involved in reproduction e.g. muscle, nerve, and connective.

Question 2

How do somatic cells divide?

Answer 2

Somatic cells only divide by mitosis to form more somatic cells.

Question 3

After mitosis does a somatic cell remain as a haploid or diploid cell?

Answer 3

Diploid

Question 4

What are germline cells?

Answer 4

Germline cells are gametes (sperm and ova) .

Question 5

What type of cell division only occurs in germline cells?

Answer 5

Meiosis

Question 6

What is differentiation?

Answer 6

The process by which a cell expresses genes to produce proteins characteristic for that type of cell. This allows a cell to carry out specialised functions.

Question 7

Where are embryonic stem cells found?

Answer 7

In the very early embryo (blastocyst).

Question 8

What types of cells can embryonic stem cells differentiate into?

Answer 8

Embryonic stem cells differentiate into all cell types that make up the individual, so are pluripotent.

Question 9

What does pluripotent mean?

Answer 9

This is where all the genes in an embryonic stem cell can be expressed.

Question 10

What are tissue stem cells required for?

Answer 10

The growth, repair and renewal of the cells found in the tissue they are found in.

Question 11

What type of cells can tissue stem cells differentiate into?

Answer 11

Tissue stem cells can differentiate into all types of cells found in a particular tissue, therefore they are multipotent.

Question 12

What does multipotent mean?

Answer 12

This is where only some of the genes in a tissue cell can be expressed.

Question 13

What are stem cells?

Answer 13

Stem cells are unspecialised cells which can differentiate to form specialised cells.

Question 14

What types of cells may develop from tissue stem cells in bone marrow?

Answer 14

Red blood cells, white blood cells, platelets etc.

Question 15

What are the therapeutic uses of stem cells?

Answer 15

This involves the repair of damaged or diseases organs or tissues. For example, regeneration of damaged skin or corneal repair.

Question 16

What are the research uses of stem cells?

Answer 16

This involves stem cells being used as model cells to study how diseases develop and for drug testing.

Question 17

What information does research uses of stem cells provide?

Answer 17

Provides information on cell processes such as cell growth, differentiation and gene regulation work.

Question 18

What are the ethical consideration of using embryonic stem cells?

Answer 18

Use of embryonic stem cells can offer effective treatment for disease and injury, however involves the destruction of embryos.

Question 19

What is cancer caused by?

Answer 19

Cancer is caused when cells of the body divide uncontrollably and excessively. This results in a mass of abnormal cells called a tumour.

Question 20

Why do cancer cells divide excessively?

Answer 20

This is because they do not respond to regulatory signals.

Question 21

How are secondary tumours created?

Answer 21

This happens when cells within the tumour fail to attach to each other, spreading through the body to form secondary tumours.