Exam 4 Lecture 43 stem cells

Question 1

Qualities of stem cells

Answer 1

1. Are NOT terminally differentiated
2. Can continue to divide without limit
3. Are self-renewing (i.e., one of the daughter cells remains as a stem cell)

Question 2

What special capability do stem cells have?

Answer 2

They can regenerate tissue over a lifetime

Question 3

Potencies of stem cells (5)

Answer 3

totipotent, pleuripotent, multipotent, oligopotent, unipotent

Question 4

totipotent

Answer 4

Can make every kind of cell

Question 5

pleuripotent

Answer 5

Can make almost any kind of cell

Question 6

multipotent

Answer 6

Can make multiple but limited cell types

Question 7

oligopotent

Answer 7

Can make a few cell types

Question 8

unipotent

Answer 8

Makes only one kind of cell

Question 9

Transit amplifying cell

Answer 9

daughter cell destined for differentiation

Question 10

When does transit amplifying cell divide?

Answer 10

It may divide multiple times before differentiation. It often divides more rapidly than a step cell.

Question 11

Animal body plans are generated from

Answer 11

Embryonic stem cells

Question 12

Regeneration and renewal of tissues/body parts depends on

Answer 12

Adult stem cells

Question 13

Two types of asymmetric cell division

Answer 13

Intrinsic (divisional) and extrinsic (environmental)

Question 14

Intrinsic asymmetry

Answer 14

Involves segregation of certain molecules to one side of the cell so that resulting daughter cells receive unequal amounts of those molecules

Question 15

Why internal polarity in stem cell

Answer 15

Asymmetrical distribution of molecules within cell

Question 16

centrosomes and intrinsic asymmetry

Answer 16

Distributed asymmetrically to daughter cells

Younger centrosomes causes differentiation

Question 17

Stem cell niche

Answer 17

microenvironment around stem cells that provides support and signals; regulates self-renewal and differentiation

Question 18

Why might some cancer cells survive radiation?

Answer 18

May be slowly dividing stem cells

Question 19

Transit amplifying cells

Answer 19

From stem cells and divide a discrete number of times. Progeny differentiate.

Question 20

ABC transporters

Answer 20

Pump drugs out of cells. Cancer cells may have a lot of these, so can avoid medication.

Question 21

Why are cancer stem cells resistant to anti-cancer to drugs?

Answer 21

abc transporter and low rate of cell division

Question 22

Oct4 and Sox2

Answer 22

Transcription factors that function in maintaining pluripotency in both early embryos and ES cells

Question 23

c-Myc and Klf4

Answer 23

Transcription factors that modify chromatic structure so that Oct4 and Sox2 can bind to their target. c-Myc controls cell proliferation.

Question 24

Producing induced pluripotent stem cells (iPS)

Answer 24

Transcription wave 1
Activate OSKM expression
Differentiated fibroblast
Loss of fibroblast specific marker protein
Transcription wave 2
Gain of embryonic marker protein
Endogenous OCT4 gene switched on