Stem Cells

Question 1

What are stem cells?

Answer 1

They are undifferentiated cells that can continually divide and become specialised.

Question 2

What are totipotent stem cells?

Answer 2

Stem cells that can divide and produce any type of body cell

Question 3

Where can you get totipotent stem cells from?

Answer 3

From early mammalian stem cells - available for a very limited time

Question 4

What are pluripotent stem cells?

Answer 4

Can be used to regrow damaged cells in humans as they can become almost every type of body cell

Question 5

Where are pluripotent stem cells found?

Answer 5

Embryo - when it is in the form of a blastocyst

Question 6

What are the issues with pluripotent stem cells?

Answer 6

They can continually divide and make tumours. Also, sometimes the treatment doesn’t work.

Question 7

What can’t pluripotent stem cells specialise to form?

Answer 7

Placenta

Question 8

What are the ethical issues surrounding stem cells?

Answer 8

There is a debate on whether it is right to make a therapeutic clone of yourself by making an embryo just to use the stem cells and then destorying that embryo.

Question 9

Where are multipotent stem cells found?

Answer 9

found in mature mammals e.g. bone marrow

Question 10

Where are unipotent stem cells found?

Answer 10

found in mature mammals

Question 11

What stem cell can differentiate into a limited number of cells?

Answer 11

Multipotent stem cell

Question 12

What stem cell can differentiate into only one (same) type of cell? Give an example:

Answer 12

Unipotent stem cell, so a muscle cell can only differentiate into more muscle cells

Question 13

Which stem cells does the umbilical cord blood contain?

Answer 13

Multipotent

Question 14

Which stem cells does the placenta contain?

Answer 14

Multipotent

Question 15

Which stem cells does the embryo contain after 16 days of fertilisation?

Answer 15

Pluripotent

Question 16

Which stem cells does the bone marrow contain?

Answer 16

Multipotent

Question 17

What does iPS stand for?

Answer 17

Induced pluripotent stem cells

Question 18

What makes a cell no longer specialised?

Answer 18

When all of the genes in that cell are turned on

Question 19

What are induced pluripotent stem cells?

Answer 19

They are adult somatic (body) cells that have come from a volunteer and certain trancriptional factors are used to control the expression of certain genes - turning all of the genes on makes the cell unspecialised, it overcomes some of the ethical issues as there is no therapeutic cloning and no destruction of an embryo.

Question 20

What are iPS cells created from?

Answer 20

Adult unipotent cells

Question 21

The adult unipotent stem cells are altered to a state of …? In order to create iPS

Answer 21

pluripotency (state of pluripotency)

Question 22

How do we switch on all of the genes in order to alter an adult unipotent cell to a state of pluripotency?

Answer 22

using transcriptional factors

Question 23

What property do iPS cells have?

Answer 23

They have shown self-renewal propertiescan divide indefinitely to give limitless supplies.