2.3 Stem Cells

Question 1

Zygote def

Answer 1

The single new cell formed by the fusion of gametes in sexual reproduction

Question 2

Embryonic stem cells def

Answer 2

Stem cells from an early embryo that can differentiate to form the specialised cells of the body

Question 3

Adult stem cells def

Answer 3

Stem cells that are found in adults that can differentiate and from a limited number of cells

Question 4

Where is a good source of adult stem cells?

Answer 4

Bone marrow

Question 5

Are there stem cells in any other part of the body?

Answer 5

Yes, there is a tiny number of stem cells in most of the different tissues eg blood, brain, muscles, liver

Question 6

What are some examples of diseases in which removing damaged body parts would be useful?

Answer 6

• Spinal injuries that cause paralysis (spinal nerves cannot repair themselves)
• People with type 1 diabetes (specialised cells in the pancreas don’t work)

Question 7

What breakthrough happened in 1998?

Answer 7

Two scientists managed to culture human embryonic stem cells (they can form any type of cell)

Question 8

What scientific trials happened in 2010?

Answer 8

Scientists injected nerve cells grown from embryonic stem cells into the spinal cord of paralysed people

Question 9

What trial happened in 2014?

Answer 9

Doctors transplanted embryonic stem cells into the eyes of people going blind as a result of macular degeneration. It was successful

Question 10

How are scientists hoping to help people with type 1 diabetes?

Answer 10

They are using different type of stem cells to grow cells that are sensitive to sugar levels and produce the hormone insulin

Question 11

What conditions could be treated with stem cells?

Answer 11

Lots from infertility to dementia

Question 12

How could embryonic stem cells be used in transplant surgery?

Answer 12

They could be used for growing whole new organs which can then be transplanted

Question 13

Where are stem cells found in plants?

Answer 13

Meristems

Question 14

How can plant stem cells be used?

Answer 14

• Can be used to make clones of the mature plant parent very quickly and economically (rare plants can be produced reliably and safely)
• Plants can be produced special features (eg disease resistance)
• can help save plants from extinction

Question 15

Identify the advantages of using stem cells to treat diseases

Answer 15

Embryonic stem cells can make any type of adult cell
to repair or replace damaged tissues.
Could grow organs for transplants as needed.
Organs grown from stem cells could cause fewer rejection issues if right
techniques are used.

Question 16

Suggest how cloning enables us to save rare plant species

Answer 16

Single rare plant specimen may not reproduce or researchers may not
understand conditions needed for it to thrive.
If specimen dies or does not make seeds, species will be lost.
Cloning allows scientists time to find out about the plant and to find other
specimens to introduce long‑term genetic variation.