Totipotent and Stem Cells

Question 1

What are stem cells?

Answer 1

Cells that can divide by mitosis an unlimited number of times that have the potential to differentiate into any kind of cell.

Question 2

What is potency?

Answer 2

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

Question 3

Name the 3 types of potency.

Answer 3

Totipotent
Pluripotent
Multipotency

Question 4

What are totipotent stem cells?

Answer 4

Cells that can divide and differentiate into any type of body cell.

Question 5

Where do totipotent cells come from?

Answer 5

Embryos

Question 6

What are zygotes and are they pluri, multi or totipotent?

Answer 6

Zygotes are the cell produced after fertilisation. They are totipotent because the stem cells can become any type of cell.

Question 7

How do totipotent cells specialise?

Answer 7

They translate only part of their DNA.

Question 8

Why are there no totipotent cells present in the later stages of life?

Answer 8

Cells lose their ability to differentiate into any cell type.

Question 9

What does it mean to say that genes are ‘switched off’?

Answer 9

They are not translated because the cell does not require those genes for their function.

Question 10

What are pluripotent stem cells?

Answer 10

Embryonic stem cells that can differentiate into any type of cell found in the embryo, but not into placenta cells.

Question 11

What can pluripotent stem cells be used for?

Answer 11

Treating human disorders.

Question 12

What type of cells are least totipotent?

Answer 12

Adult stem cells, that are created once the fetus has formed.

Question 13

Name 4 places that stem cells can come from, listing from most to least totipotent.

Answer 13

Most - Embryo
Umbilical cord blood.
Placental stem cells
Least - Adult stem cells.

Question 14

In adults, what can induced pluripotent stem cells be produced from?

Answer 14

Any body cell that is not a gamete.

Question 15

Where do adult stem cells come from?

Answer 15

Bone marrow

Question 16

What are the uses of adult stem cells?

Answer 16

Growth and repair

Question 17

Compare multipotent and pluripotent stem cells.

Answer 17

Pluripotent stem cells can differentiate into almost any kind of cell. Multipotent stem cells can differentiate into most cells.

Question 18

Describe how induced pluripotent cells can be produced.

Answer 18

The genetics of cells are altered to have characteristics of embryonic stem cells by inducing genes and transcription factors.

Question 19

Why must induced pluripotent stem cells be produced from an individuals own body cells?

Answer 19

To prevent rejection.

Question 20

Explain what multipotent cells are.

Answer 20

Adult stem cells that can only differentiate into a small number of cells.
Eg: cardiac tissue cells may differentiate into cardiac muscle cells etc

Question 21

What are unipotent cells?

Answer 21

Adult stem cells that can only differentiate into their own cell type after dividing.
For example, heart muscle cells will only divide into heart muscle cells.

Question 22

Give 2 characteristics of stem cells.

Answer 22

Can differentiate into many types of cell.
Can replace themselves by continuing to divide.