3.8.2.1 Most of a cell’s DNA is not translated

Question 1

What are totipotent cells?

Answer 1

Totipotent cells can divide and produce any type of body cell.

Question 2

When are totipotent cells present in mammals?

Answer 2

Totipotent cells occur only for a limited time in early mammalian embryos.

Question 3

How does cell specialisation occur during development?

Answer 3

Totipotent cells translate only part of their DNA resulting in cell specialisation.

Question 4

Where are pluripotent cells found?

Answer 4

Pluripotent cells are found in embryos.

Question 5

Where are multipotent and unipotent cells found?

Answer 5

Multipotent and unipotent cells are found in mature mammals.

Question 6

What types of cells can multipotent and unipotent cells form?

Answer 6

Multipotent and unipotent cells can divide to form a limited number of different cell types.

Question 7

What is a key feature of pluripotent stem cells in treatment?

Answer 7

Pluripotent stem cells can divide in unlimited numbers and can be used in treating human disorders.

Question 8

What is an example of unipotent cell function?

Answer 8

Unipotent cells are exemplified by the formation of cardiomyocytes.

Question 9

How are induced pluripotent stem cells (iPS cells) produced?

Answer 9

Induced pluripotent stem cells (iPS cells) are produced from adult somatic cells using appropriate protein transcription factors.

Question 10

Why are pluripotent stem cells useful in medical treatment?

Answer 10

Pluripotent stem cells can divide indefinitely and differentiate into almost any cell type offering potential for treating human disorders.

Question 11

What ethical issues arise with the use of embryonic stem cells?

Answer 11

The use of embryonic stem cells raises ethical concerns as it involves the destruction of human embryos.

Question 12

What is an advantage of iPS cells over embryonic stem cells?

Answer 12

iPS cells avoid ethical issues as they do not require the destruction of embryos.

Question 13

What is a limitation of using iPS cells?

Answer 13

iPS cells may pose risks such as tumour formation and may not fully replicate the properties of natural pluripotent cells.

Question 14

What is a key concern in stem cell therapy?

Answer 14

Immune rejection can be a significant concern when stem cells are derived from a donor.

Question 15

Give two features of stem cells.

Answer 15

will replace themselves

OR

will keep dividing/replicating

undifferentiated

OR

can differentiate/develop into other cells

OR

totipotent/multipotent/pluripotent