stem cells

Question 1

what are the three types of stem cells

Answer 1

embryonic stem cells, adult stem cells, induced pluripotent stem cells

Question 2

how is a zygote created

Answer 2

sperm fuses with an egg

Question 3

in early mammalian development, what happens to the zygote once its formed

Answer 3

undergoes cleavage

Question 4

what does cleavage of a zygote produce

Answer 4

an eight-celled stage

Question 5

at the eight-celled stage of a cleaved zygote, each cell is ___potent

Answer 5

totipotent

Question 6

define totipotent

Answer 6

each cell has the potential to form every tissue (embryonic and extraembryonic)

Question 7

what is formed after the eight-celled mass undergoes cleavage

Answer 7

morula

Question 8

how many cells in a morula

Answer 8

16

Question 9

what is formed after a morula

Answer 9

blastocyst

Question 10

how many cells in a blastocyst

Answer 10

64

Question 11

what is a morula

Answer 11

has 16 cells, the cells are a compact + solid mass

Question 12

at what stage of zygote cleavage do we get our first differentiation event

Answer 12

the 64 cell stage (blastocyst)

Question 13

what two cell types are generated in the blastocyst stage (the differentiation event)

Answer 13

trophectoderm (TE) and inner cell mass (ICM)

Question 14

where is the inner cell mass of a blastocyst located

Answer 14

on one side of the blastocoel

Question 15

what is the blastocoel

Answer 15

the fluid-filled cavity within the blastocyst

Question 16

what is the trophectoderm of a blastocyst

Answer 16

it forms a hollow ball around the ICM and the blastocoel

Question 17

from which part of the blastocyst can embryonic stem cells be isolated from

Answer 17

they’re isolated from the inner cell mass

Question 18

T or F: ES cells can be grown indefinitely in culture

Answer 18

true

Question 19

ES cells are ___potent

Answer 19

pluripotent

Question 20

define pluripotent

Answer 20

they can differentiate into a wide range of cell types of the three primary germ layers (ie into cells that are NOT extraembryonic)

Question 21

what is an example of an extra-embryonic cell

Answer 21

placental cells

Question 22

what type of cells can ES cells differentiate into

Answer 22

cell types of the three primary germ layers

Question 23

describe how we would use ES cells to grow tissue in a mouse

Answer 23

isolate the ES cells from the ICM of the early embryo/blastocyst, then culture them. Inject a clump into the recipient blastocyst and then these will be incorporated into the ICM of the host blastocyst, and then the blastocyst will differentiate into tissue

Question 24

therapeutic uses of ES cells?

Answer 24

restore or replace any damaged tissue

Question 25

give three examples of cell types that ES cells can differentiate into

Answer 25

liver, nerve, blood

Question 26

how can we make ES cells differentiate into different cell types

Answer 26

different culture conditions = different types of differentiated cells

Question 27

other than different cell types, what can ES cells give rise to?

Answer 27

organoids

Question 28

define organoid

Answer 28

an organ-like structure

Question 29

how are organoids produced

Answer 29

by using ES cells

Question 30

list 3 problems with ES cells

Answer 30

ethical issues, immune rejection, and formation of teratomas

Question 31

what is a teratoma

Answer 31

a benign tumor

Question 32

how does one get a teratoma

Answer 32

arises if you have ES cells that haven't differentiated

Question 33

what is the full name for iPS cells

Answer 33

induced pluripotent stem cells

Question 34

what did Shinya Yamanka do

Answer 34

came up with a procedure that allowed them to reprogram a differentiated mouse cell back to a pluripotent stem cell

Question 35

how are iPS cells similar to ES cells

Answer 35

they are pluripotent and can divide indefinitely

Question 36

T or F: iPS cells are totipotent

Answer 36

false; they are pluripotent

Question 37

T or F: iPS cells can divide indefinitely

Answer 37

true

Question 38

describe in simple terms how iPS cells are made, starting with a differentiated cell (ie skin fibroblast cell)

Answer 38

skin fibroblast cell gets 4 regulator genes added to it = iPS cell

Question 39

advantages of iPS cells

Answer 39

no ethical problems, can generate tissue-compatible iPS cells

Question 40

problems with iPS cells?

Answer 40

lengthy and inefficient process, heterogeneity in the population of cells produced, undifferentiated iPS cells can result in a teratoma

Question 41

why are adult stem cells important

Answer 41

many cells in the body need to constantly be replaced, and this = loss of differentiated cells, so adult stem cells supply new ones = organ homeostasis

Question 42

when an adult stem cell is made, what are the two options for it

Answer 42

differentiation or self-renewal

Question 43

what are progenitor cells

Answer 43

kinda like precursor cells: arise when an adult stem cell is undergoing differentiation but hasn't gone all the way yet (ie it's a population that's made on the way)

Question 44

T or F: the choice for adult stem cells to either differentiate or self-renew must be kept in balance

Answer 44

true

Question 45

where in the body do adult stem cells hang out when either self renewing or differentiating

Answer 45

in stem cell niches

Question 46

what is a stem cell niche

Answer 46

a microenvironment in tissues

Question 47

list 3 self renewing tissues

Answer 47

skin, intestinal epithelium, and blood

Question 48

what 2 types of differentiated cells can divide and self renew without the aid of stem cells

Answer 48

pancreatic-B cells and liver cells

Question 49

which tissues in mammals can't renew bc they lack stem cells

Answer 49

auditory epithelium, and the retinal photoreceptive epithelium

Question 50

adult stem cells are ___potent

Answer 50

multipotent

Question 51

define multipotent

Answer 51

can generate a limited number of different cell types

Question 52

in the small intestine, where are stem cells located

Answer 52

in crypts

Question 53

what are crypts of the small intestine

Answer 53

the little cavern things of villi

Question 54

describe the movement of stem cells in the small intestine as they differentiate

Answer 54

they move from the crypt to the top of the villus

Question 55

what 4 cells can adult stem cells differentiate into within the small intestine

Answer 55

enterocyte, tuft cell, enteroendocrine cell, and goblet cell

Question 56

list the 2 major blood cell types

Answer 56

RBCs and WBCs

Question 57

list the types of WBCs

Answer 57

granulocytes, monocytes, lymphocytes, and natural killer cells

Question 58

where are blood cells produced

Answer 58

bone marrow

Question 59

T or F: all blood cell types are produced by a single stem cell type

Answer 59

true!

Question 60

what stem cell type produces every blood cell

Answer 60

hematopoietic stem cell (HSC)

Question 61

what do hematopoietic stem cells do

Answer 61

they produce blood cells

Question 62

other than blood cells, what two types of cells do hematopoietic cells produce

Answer 62

myeloid progenitor cell or lymphoid progenitor cell

Question 63

myeloid progenitor cells are __potent

Answer 63

multipotent

Question 64

lymphoid progenitor cells are __potent

Answer 64

multipotent

Question 65

T or F: myeloid progenitor + lymphoid progenitor cells are stem cells

Answer 65

false! they are not stem cells

Question 66

why are myeloid/lymphoid progenitor cells not considered stem cells, even if they are multipotent

Answer 66

they are not capable of continued self-renewal

Question 67

what cells do lymphoid progenitor cells produce

Answer 67

T cells, B cells, NK celsl

Question 68

what cells do myeloid progenitor cells produce

Answer 68

dendritic, granulocytes, macrophages, platelets, and RBCs