Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

AS/A-Level Biology > CGE: Stem Cells COPY > Flashcards

CGE: Stem Cells COPY Flashcards

You may prefer our related Brainscape-certified flashcards:
AP® Biology flashcards Biology 101 flashcards
1
Q

Totipotent stem cells

A

Can mature into any type of body cell.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

All specialised cells come from what?

A

Stem cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Where can stem cells be found?

A

In the embryo and in some adult tissues.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Where are totipotent stem cells present?

A

Only present in mammals in the first few cell divisions of an embryo.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What happens to totipotent stem cells in mammals after the first few cell divisions?

A

They become pluripotent.

Can still specialise into any cell in the body, but lose the ability to become cells that make up the placenta.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Stem cells in adult mammals are either…

A

Multipotent or unipotent

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Pluripotent stem cells

A

Stem cells that can specialise into any body cell, but have lost the ability to differentiate into cells that make up the placenta.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Multipotent stem cells

A

Stem cells that can differentiate into a few different types of cell.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Unipotent stem cells

A

Stem cells that can only differentiate into one type of cell.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Can mature into any type of body cell.

A

Totipotent stem cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Stem cells that can specialise into any body cell, but have lost the ability to differentiate into cells that make up the placenta.

A

Pluripotent stem cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Stem cells that can differentiate into a few different types of cell.

A

Multipotent stem cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Stem cells that can only differentiate into one type of cell.

A

Unipotent stem cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Describe the process of stem cells becoming specialised:

A
  • Under the right conditions, some genes are expressed and others are switched off.
  • mRNA is only transcribed from specific genes.
  • mRNA from these genes is translated into proteins.
  • Proteins modify the cell - determine the cell structure and control cell processes.
  • Changes to the cell produced by proteins = cell is specialised.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Give an example of a cell becoming specialised:

A
  • Stem cell produces new cell where the genes for haemoglobin production are expressed.
  • Other genes, eg. those involved in removing the nucleus, are expressed too.
  • Many other genes are not expressed.
  • Specialised red blood cell forms.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Cardiomyocytes

A

Heart muscle cells that make up the heart tissue.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What was previously thought about cardiomyocytes?

What has new research shown?

A

Previously thought they could not divide to replicate themselves.

Research has suggest hearts have some regenerative capability.

18
Q

What is the main use of stem cells?

A
  • Stem cell therapy to treat disorders.
19
Q

What diseases do stem cell therapies already exist for?

A

Diseases affecting the blood and immune system.

20
Q

What does bone marrow contain?

A

Stem cells that can become specialised to form any type of blood cell.

21
Q

What are bone marrow transplants used for?

A

To replace the faulty bone marrow in patients that produce abnormal blood cells.

22
Q

What has stem cell therapy been successfully used for?

A

To treat leukaemia (cancer of the blood or bone marrow) and lymphoma (a cancer of the lymphatic system).

23
Q

What is SCID?

A

Severe combined immunodeficiency.

A genetic disorder that affects the immune system.

24
Q

How does SCID affect an individual?

A
  • Poorly functioning immune system as white blood cells are defective.
  • So they can’t defend the body against infections by identifying and destroying microorganism.
  • Leaves them extremely susceptible to infections.
25
Q

What is the treatment for SCID?

A
  • Bone marrow transplant replaces faulty bone marrow with donor bone marrow that contains stem cells without faulty genes.
  • These differentiate to produce functional white blood cells - can identify and destory invading pathogens = immune system functions properly.
26
Q

What uses of stem cells are scientists researching?

A
  • Spinal cord injuries - replace damaged nerve tissues
  • Heart disease and damage to heart .
  • Bladder conditions - grow new bladders which can replace diseased ones.
  • Respiratory diseases - donated windpipes can be stripped to collagen structures and covered with tissues generated by stem cells.
  • Organ transplants - organs can be grown from stem cells to provide new organs for people on donor waiting lists.
27
Q

What are the two main benefits of stem cells?

A
  • Could save many lives - eg. could be used to grow new organs for people awaiting transplants.
  • Could improve quality of life - eg. replace damaged cells in blind patients.
28
Q

What are the 3 main potential sources of human stem cells?

A
  • Adult stem cells
  • Embryonic stem cells
  • Induced pluripotent stem cells (iPS cells)
29
Q

Where are embryonic stem cells obtained from?

How?

A

Obtained from body tissues of an adult, eg bone marrow.

Obtained through a simple operation - little risk but lots of discomfort.

30
Q

What is the main limitation of adult stem cells?

A

Not as flexible as embryonic - they’re multipotent.

31
Q

Where are embryonic stem cells obtained and how?

A

From embryos at early stage of development.

  • In vitro fertilisation - fertilises egg cells outside the womb.
  • At approx. 4-5 days old stem cells are removed.
  • Embryo destroyed.
    *
32
Q

What type of stem cells are embryonic stem cells?

A

Pluripotent

33
Q

What type of stem cells are adult stem cells?

A

Multipotent

34
Q

What are iPS cells?

A

Induced pluripotent stem cells.

Created by scientists in the lab by ‘reprogramming’ specialised adult body cells so that they become pluripotent.

35
Q

How are adult body cells turned into iPS cells?

A
  • Made to express a series of transcription factors that are associated with pluripotent stem cells.
  • Caused by transcription factors.
36
Q

How can transcription factos be introduced to the adult stem cells to help them become iPS cells?

A
  • Infection with a specially-modified virus.
  • Virus contains genes coding for transcription factors within its DNA.
  • Upon infection, these genes are passed into adult cell’s DNA.
  • Adult stem cell can now produce transcription factors.
37
Q

Why is the use of iPS cells currently limited?

A

More research is needed to test the similarity to true pluripotent embryonic stem cells.

38
Q

What are some ethical issues surrounding stem cell usage?

A
  • Destruction of an embryo - could become a fetus if placed in womb.
39
Q

What would be a solution to the ethical issues surrounding the use of embryonic stem cells?

A

iPS cells - can be as flexible as embryonic cells but don’t result in the destruction of an embryo.

40
Q

How could iPS cells become even more useful?

A

If they are made from a patient’s own cells - would be genetically identical to patient’s cells and so wouldn’t reject.

AS/A-Level Biology (190 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions