1.1 Differentiation & Stem Cells Flashcards Preview

Higher Human Biology Unit 1 🌀 > 1.1 Differentiation & Stem Cells > Flashcards

Flashcards in 1.1 Differentiation & Stem Cells Deck (34)
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1
Q

What is differentiation?

A

Differentiation is the process by which an unspecialised cell becomes altered and adapted to perform a particular function

2
Q

What happens once a cell becomes differentiated

A

It only expresses the genes that produce the proteins characteristic for that type of cell

3
Q

List some examples of specialised cells

A

Ciliated epithelial cell - cilia gently sweep mucus upwards and away from the lungs
Nerve cell - long which allows it to carry electrical impulses
Red blood cell - biconcave shape presents a large absorbing surface area for the absorption of oxygen
Goblet cell - produces mucus

4
Q

List some examples of tissue

A

Muscle tissue, connective tissue, epithelial tissue, nervous tissue

5
Q

Define stem cell

A

A stem cell is an unspecialised cell that can divide to make copies of themselves (self-renew) and/or differentiate into specialised cells

6
Q

What are the two main types of stem cell

A

Embryonic and tissue (adult) stem cells

7
Q

Where are embryonic stem cells derived from

A

An embryo that is about 4-5 days old, known as a blastocyst

8
Q

What does pluripotent mean

A

The embryonic stem cells can develop into any of the 200 plus cell types of the adult body

9
Q

What are ethical issues with the use of embryonic stem cells

A

It involves the destruction of embryos which many believe to be unethical as it has the potential to grow into a baby. However once the time for keeping spare embryos is up they are destroyed anyway.

10
Q

Where can adult (tissue) stem cells be found

A

The skin, muscle, intestine and bone marrow

11
Q

What are adult (tissue) stem cells said to be

A

Multipotent

12
Q

What does multipotent mean

A

They have the ability to divide into only several distinct cell types, usually similar to the tissue that surrounds them ( they give rise to a more limited range of cell types )

13
Q

What are ethical issues with the use of adult tissue stem cells

A

Not controversial. Doesnt require the destruction of an embryo. The patients own stem cells can be harvested for use - rejection of tissue will not be an issue

14
Q

What are therapeutic applications of stem cells?

A

Bone marrow transplatation, skin grafts and corneal grafts

15
Q

What are future developments of stem cells

A

Heart muscle - repairing damaged heart muscle after a heart attacm
Bladder - building a new bladder in a laboratory if a patients bladder has been damaged due to injury or disease

16
Q

What can stem cells be used as

A

They can be used as model cells to study how diseases develop and for drug testing

17
Q

What is a somatic cell

A

A somatic cell is a differentiated cell that forms different types of tissue that exist

18
Q

What cells are somatic

A

All body cells are somatic like skin, nerve and muscle cells.

19
Q

Somatic cells are (diploid/gamete)

A

Diploid

20
Q

What do somatic cells divide by mitosis to form

A

More somatic cells

21
Q

What is a germline cell

A

A germline cell is a cell that will become a gamete or a cell that produces gametes

22
Q

What happens when cancer cells divide uncontrollably

A

A mass of abnormal cells

23
Q

What happens if cancer cells do not respond to regulatory signals

A

They may fail to attach to each other

24
Q

What happens if cancer cells fail to attach to each other

A

They can spread through the body and form secondary tumours

25
Q

What is a tumour

A

A mass of abnormal cells that divide uncontrollably

26
Q

What are the two types of tumour

A

A benign tumour and a malignant tumour

27
Q

What metastasise mean?

A

To spread around the body

28
Q

Does a benign tumour metastasise?

A

No

29
Q

What are examples of benign tumours

A

Moles and warts

30
Q

Are benign tumours harmful and can they be removed

A

Benign tumours dont normally cause problems and can be removed by surgery

31
Q

What is a malignant tumour

A

A tumour that can spread to other parts of the body

32
Q

What happens to the cells in malignant tumours

A

The cells are cancerous. The cells do not respond to regulatory signals which causes them to fail to attach to each other. They can them spread around the body forming secondary tumours

33
Q

What does the risk of cancer increase with

A

Age

34
Q

How can the risk of cancer be increased by

A

Agents such as cigarette smoke, polltion and ultraviolet radiation