Stem cells

Question 1

define stem cells

Answer 1

stem cells are cells that are capable of self-renewal or differentiation into a specialised cell type

Question 2

what is self renewal?

Answer 2

The ability of a cell to divide to produce more of itself

Question 3

what is difeerentiation?

Answer 3

is the process by which one cell type turns into another

Question 4

how many cells does a c.elegan have?

Answer 4

1031 or 959

Question 5

how many cells approx. does a human have?

Answer 5

1 x 10^10

Question 6

what are haematopoetic stem cell (HSC) ?

Answer 6

stem cells of the blood

Question 7

what is life span of blood cell?

Answer 7

days to several months

Question 8

what are HSCs?

Answer 8

A pool of stem cells that can self-renew and differentiate to replenish the blood system

Question 9

What is used to treat blood cancers normally?

Answer 9

radiation treatment or chemotherapy

Question 10

name two blood cancers?

Answer 10

leukaemia and lymphoma

Question 11

Why would a bone marrow transplant of HSCs be used?

Answer 11

to reconstitute the blood system after its been destroyed

Question 12

How many HSC can repopulate a mices enture immune system?

Answer 12

one

Question 13

Give examples of adult stem cells? (stem cells grown in a lab isolated form adult tissues and grown in vitro)

Answer 13

Haematopoetic stem cells, mesechymal stem cells, neural stem cells

Question 14

what are stem cells isolated from adult tissues called?

Answer 14

multipotent

Question 15

why can adult stem cells be limited in supply in medicine?

Answer 15

although they self renewal they eventually senesce - after a certain number of cell divisions they get old and stop dividing

Question 16

where can pluripotent cells be derived from?

Answer 16

adult tissues or from embryonic tissues

Question 17

name two types of pluripotent stem cells?

Answer 17

embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs)

Question 18

what are ESCs?

Answer 18

• derived from early embryos
• can be grown in dishes indefinitely but exist only transiently in nature
• can differentiate into all of the cell types found in adult organisms

Question 19

what is pluripotency ?

Answer 19

when a stem cell can differentiate into all of the cell types found in the adult organism

Question 20

How were embryonic stem cells derived originally from mice ?

Answer 20

the method involved extracting 3.5 day old blastocysts from mice and putting them in a cell culture dish with another cell type

Question 21

what do ESCs cause if implanted in mice?

Answer 21

teratomas

Question 22

when does a chimera form?

Answer 22

when two embryos fuse after fertilisation leading to the formation of a single person made up of two distinct genetic entities