Stem Cells

Question 1

What are stem cells?

Answer 1

They are unspecialised cells that can differentiate into specialised cells.

Question 2

What are totipotent stem cells? What can they be used for?

Answer 2

These are stem cells that can differentiate into any other body cells, including extra-embryonic stem cells. They can therefore used to make a whole organism.

Question 3

How do totipotent cells become specialised?

Answer 3

They transcribe and translate only part of their DNA.

Question 4

Where can totipotent cells be found and for how long?

Answer 4

They are only found in mammalian embryos for a limited time after conception.

Question 5

What are pluripotent stem cells? What can they be used for?

Answer 5

These are stem cells that can differentiate into any other type of body cell except embryonic stem cells.

Question 6

Where can pluripotent cells be found and for how long?

Answer 6

They can be found in mammalian embryos after the first few cell divisions.

Question 7

What are multipotent stem cells? What can they be used for?

Answer 7

These are stem cells that can only differentiate into a limited number of body cells. They are found in the bone marrow and can differentiate into different types of blood cells.

Question 8

Where can multipotent cells be found?

Answer 8

They can be found in the bone marrow of adult mammals.

Question 9

What are unipotent stem cells? What can they be used for?

Answer 9

They ate stem cells that can divide into only one type of cell.

Question 10

THE PRODUCTION OF INDUCED PLURIPOTENT STEM CELLS.

Question 11

How are induced pluripotent cells produced?

Answer 11

1. In adult somatic cells, transcription factors induce the expression of genes that need to be activated in pluripotent cells.
2. This causes the somatic cells to differentiate and become unspecialised.
3. This means they can differentiate into any type of body cell and become specialised

Question 12

What are some of the medical uses for induced pluripotent cells?

Answer 12

1. These stem cells can be used to differentiate into any type of body cell, such as healthy beta cells, to replace the damaged ones in the pancreas. This means it can be used to treat Type 1 diabetes.

Question 13

What are the benefits of the use of induced pluripotent stem cells?

Answer 13

1. These stem cells are made from the body’s adult cells meaning the immune system won’t reject the cells.
2. They can divide and differentiate without limit.

Question 14

THE ETHICS OF USING STEM CELLS.

Question 15

What are the arguments for using stem cells in medicine?

Answer 15

1. It could save lives or improve the quality of life of those who have disorders.
2. The use of adult stem cells and iPS cells does not require the use of embryos.
3. iPS cells are made from adult stem cells, so the immune system is unlikely to reject them, which can cause illness.

Question 16

What are the arguments against using stem cells in medicine?

Answer 16

1. The use of multipotent or pluripotent stem cells requires destroying an embryo and a potential life.
2. If the stem cells come from another organism the body’s immune system could reject it.