3.4.1 - Stem Cells

Question 1

Describe Stem Cells
(4 Points)

Answer 1

~ Undifferentiated cells that can develop into other cell types.

~ Cells which can divide by mitosis an unlimited number of times.

~ Each new cell produced when a stem cell divides, has the potential to remain a stem cell or to develop into a specialised cell.

~ Can be found in the embryo.

Question 2

What Process Forms Specialised Cells?

Answer 2

Differentiation.

Question 3

What Is Meant By ‘Potency’?

Answer 3

The ability of stem cells to differentiate into more specialised cell types.

Question 4

What Are The Types Of Potency?
(2 Points)

Answer 4

~ Totipotency.

~ Pluripotency.

Question 5

Describe Totipotency
(2 Points)

Answer 5

~ Stem cells which can differentiate into any cell type in an embryo, as well as extra embryonic cells.

~ E.g. Zygote.

Question 6

Describe Pluripotency

Answer 6

Embryonic stem cells which can differentiate into any cell type found in an embryo, but are not able to differentiate into extra-embryonic cells as the genes for these cell types have become inactivated.

Question 7

Where Can Stem Cells Be Found?
(2 Points)

Answer 7

~ Embryo.

~ Some adult tissues, these are less potent then embryonic stem cells as they can only specialise into certain types of cells.

Question 8

Describe Stem Cells In Plants

Answer 8

They contain stem cells in areas of growth, such as the shoots and the roots.