Stem Cells

Question 1

asymmetrical division of stem cells

Answer 1

division gives rise to 1 cell with stem cell characteristics and the other with the ability to be differentiated

Question 2

adult stem cells

• what are they
• what do they respond to

Answer 2

mature stem cells; tissue specific (epidermal stem cells, intestinal stem cells, etc.)
- responds to demands of growth/repair

Question 3

totipotency

• what is it
• example and location

Answer 3

ability to give rise to all cells of an organism, including embryonic and extraembryonic tissues
ex: embryonic stem cells in the zygote

Question 4

pluripotency

• what is it
• example and location

Answer 4

ability to give rise to all cells of the embryo and subsequently adult tissues
ex: embryonic stem cells in the blastocyst

Question 5

multipotency

• what is it
• example and location

Answer 5

ability to give rise to different cell types of a given lineage (endoderm, ectoderm, or mesoderm)
ex: adult stem cells in various tissues

Question 6

how stem cells can treat diabetes

Answer 6

cultured pluripotent stem cells can be cultured to become pancreatic islet cells that can be used to treat diabetes

Question 7

how stem cells can treat leukemia/used for chemotherapy

Answer 7

cultured pluripotent stem cells can be cultured to become bone marrow cells

Question 8

founder stem cells

• what are they
• what do they do
• where are they used

Answer 8

fixed number of divisions; controlled by short range signals; each tissue has fixed number of these cells

• Constantly present in organ
• Determine organ size via signaling
• used in proportions of the body that are determined early

Question 9

transit amplifying cells

Answer 9

the daughter cell that has the ability to differentiate in stem cell division; limited, finite number of divisions

• part of strategy for growth control
• develop from stem cells

Question 10

environmental asymmetry

Answer 10

division of stem cells that is influenced from the environment; may influence or alter 1 cell

Question 11

immortal strand hypothesis

Answer 11

in stem cell division, the self-renewal cell retains exact same DNA as the parent cell, and the daughter cell gets new, mutated DNA

Question 12

embryonic stem cells

• derived from where
• development

Answer 12

• derived from blastocyst stage of embryo
• can proliferate indefinitely, unrestricted development
• develop into different cell types
• can become a tumor

Question 13

teratoma

Answer 13

a tumor made up of several different types of tissue, such as hair, muscle, or bone; typically form in the ovaries, testicles, or tailbone and less commonly in other areas

Question 14

how do ES cells give rise to teratomas

Answer 14

ES cells can differentiate into many different types of tissues; on their own, the ES cells are incapable of generating the body plan; disorganization causes tumors
- tumor is made of cells from all germ layers

Question 15

Nanog
Oct4
Sox2
FoxD3

Answer 15

transcription factors that are essential for establishment and maintenance of pluripotent stem cells in the embryo

Question 16

GCNF

Answer 16

transcription factor; required for early stages of pluripotent cell differentiation

Question 17

Cripto and GDF-3

Answer 17

growth factors found in pluripotent cells

Question 18

hematopoietic stem cells

• where are they derived from
• where are they found

Answer 18

• derived from bone marrow

- found in cord blood, bone marrow, peripheral blood

Question 19

stromal (mesenchymal) stem cells

• where are they derived from
• where are they found

Answer 19

• derived from bone marrow

- connective tissues, many other tissues (liver, muscle, nerve, etc)

Question 20

cord blood stem cells

Answer 20

third main type of stem cell; undifferentiated cells

• no gene manipulation
• can be “banked”

Question 21

three main sources of stem cells

Answer 21

embryonic
adult
cord

Question 22

two places in the body where mesenchymal stem cells can be harvested

Answer 22

bone marrow (BMSCs)
adipose tissue (AMSCs) from liposuction

Question 23

adult stem cell therapy:

• where they differentiate
• what they can differentiate into

Answer 23

they have the capacity to differentiate in vitro and in vivo

–> chondrocytes, myoblasts, osteoblasts, pancreatic beta-cells, and neuronal cells

Question 24

somatic cell nuclear transfer

SCNT cells

Answer 24

nucleus is taken from a somatic cell of a patient and injected into the oocyte of a donor, replacing the oocyte nucleus
–> blastocyst generated and ES cells isolated
Ex: Dolly

Question 25

Oct3/4, Sox2, Myc, KIf4, Nanog, Lin-28

Answer 25

transcription factors/gene regulatory factors; can induce adult human cells to exhibit properties of ES cells

Question 26

what occurs when adult stem cells are injected into the fibroblast

Answer 26

they become ES-like cells

• ability to differentiate into other cell types
• yield is low and not identical to ES cells

Question 27

iPS cells

induced pluripotent stem cells

Answer 27

a type of pluripotent stem cell that can be generated directly from adult cells

Question 28

what are the therapeutic potentials and ethical benefits of using iPS cells and SCNT cells

Answer 28

• solves tissue rejection problem (cells express patient’s genes)
• cells are custom made for patients
• enable reprogramming of adult cells while omitting embryo step
• study disease development and develop drugs

Question 29

in somatic cell nuclear transfer, what is the downside of stopping production at the fusion step

Answer 29

this prohibits cloning which restricts any therapeutic application; the cell doesn’t divide if you restrict this

Question 30

in somatic cell nuclear transfer, what is the downside of stopping implantation of the SCNT

Answer 30

restricts reproductive cloning

but allows therapeutic research to continue

Question 31

challenges for SCNT in disease treatment

Answer 31

• inefficiency (may needs hundreds of oocytes)

- technical demand - needs to be available in many or all hospitals