Stem Cells (1,2,3,4,6)

Question 1

ES cells cannot be isolated from:

a. Blastocyst
b. Neonate nerves
c. Umbilical cord blood
d. Amniotic Fluid

Answer 1

b. Neonate nerves

Question 2

What is true about pluripotent stem cells?

a. Primordial germ cells give rise to embryonic germ cells
b. Oct4, Sox2 and Nanog are only found in ES cells
c. EGCs are haploid and come from the PGCs of the gonads
d. Embryonic germ cells can be derived from the inner cell mass

Answer 2

a. Primordial germ cells give rise to embryonic germ cells

Question 3

What is not a feature shared by stem cells?

a. The ability to sense extrinsic signals and react intrinsically
b. Specialised cell cycles and high telomerase activity
c. Chromatin remodelling abilities
d. Susceptible to stress

Answer 3

d. Susceptible to stress

Question 4

• Multipotency refers to a cells ability to form derivatives of all 3 germ layers.

Answer 4

F

Question 5

• ‘Stemness’ refers to the idea that common molecular process (e.g. RNA transcripts) underlay the properties of self-renewal and differentiation.

Answer 5

T

Question 6

What is false about mouse pre-implantation development?

a. The early blastocyst is at the 64 cell stage on day 3.5
b. The ICM separates into the epiblast and hypoblast
c. The main components of the blastocyst are the trophoblast, inner cell mass and neural crest
d. The outer layer (zona pellucida) specifies the species of the embryo

Answer 6

c. The main components of the blastocyst are the trophoblast, inner cell mass and neural crest

Question 7

Which is the correct match for the derivatives of the three primary germ layers?

a. Endoderm: pancreatic cell, thyroid cell, lung cell
b. Mesoderm: Skin cell, neuron, pigment cell
c. Ectoderm : Skin cell, RBC, kidney tubule cell
d. Mesoderm: pancreatic cell, neuron, pigment cell

Answer 7

a. Endoderm: pancreatic cell, thyroid cell, lung cell

Question 8

What is true about the tests for pluripotent stem cells?

a. Teratoma formation is the most stringent test
b. In germline chimerism, the embryo is only composed of cells from the injected ES cells
c. In vitro tests are more stringent than in vivo tests but do not test the ability to promote normal development
d. Test three does not test for complete pluripotency

Answer 8

d. Test three does not test for complete pluripotency

Question 9

What is NOT a feature of mouse ES stem cell colonies?

a. They express Oct4, nanog and sox2
b. They have a flat colony morphology
c. They maintain a normal karyotype
d. They express AP and SSEA-1

Answer 9

b. They have a flat colony morphology

Question 10

A feature that differentiates human ES cells from mouse ES cells is:

a. Their dependence on LIF
b. Their rounded colony morphology
c. Their passaging as single cells
d. Their requirement for Activin and FGF in serum and feeder free culture

Answer 10

d. Their requirement for Activin and FGF in serum and feeder free culture

Question 11

What is NOT a feature of Naïve and Primed mouse ES cells?

a. Both can form chimeras
b. Both express Oct4, nanog, sox2
c. Only primed (EpiSC) have differentiation factors (brachyury and FGF5)
d. LIF only causes self-renewal in naïve mouse ES cells

Answer 11

a. Both can form chimeras

Question 12

• During fertilisation and implantation, the egg sheds excess DNA to polar bodies.

Answer 12

T

Question 13

• The trophoblast forms the embryo and the Inner Cell Mass forms the placenta.

Answer 13

F

Question 14

• Cells of the embryo are totipotent up until the 8 cell stage

Answer 14

. T

Question 15

• The zona pellucida is responsible for species specificity.

Answer 15

T

Question 16

• Mouse ES cells can be derived from the hypoblast at the late blastocyst stage.

Answer 16

F

Question 17

• LIF supresses ectoderm and BMP supresses mesoderm and endoderm.

Answer 17

F

Question 18

• Human stem cells share many characteristics with epiblast stem cells which suggests they are from a later stage of development than mouse ES cells.

Answer 18

T

Question 19

Which does not confer pluripotency?

a. Nanog
b. Oct4
c. BMP
d. Sox2

Answer 19

c. BMP

Question 20

Which is most likely to be repressed by a core pluripotency regulator?

a. A mesoderm inducing factor
b. Chromatin remodelling factor
c. TGFB signalling
d. Nanog

Answer 20

a. A mesoderm inducing factor

Question 21

Which is most likely to be activated by a core pluripotency regulator?

a. A neurogenesis inducing factor
b. Euchromatin
c. Chromatin remodelling factors
d. BMP signalling

Answer 21

c. Chromatin remodelling factors

Question 22

What is true about the bivalent chromatin state?

a. The regulatory regions in ES cells only have repressive histone modifications
b. Differentiation genes can be permanently switched off in ES cells
c. Differentiation gene repression is only permanent in EpiSC
d. Differentiation genes in ES cells are silent but poised for activation

Answer 22

d. Differentiation genes in ES cells are silent but poised for activation

Question 23

How can inhibitors impact mouse ES cells?

a. PDO3 can inhibit FGF and prevent differentiation and increase Nanog expression
b. Blocking GSK3 signalling increases Nanog expression and reduces differentiation
c. High levels of Nanog can inhibit FGF and Mek/ERK signalling
d. CHIR can inhibit the activity of FGF and GSK3 to prevent differentiation

Answer 23

a. PDO3 can inhibit FGF and prevent differentiation and increase Nanog expression

Question 24

What is false about 2i culture?

a. PDO3 and LIF block differentiation
b. The level of Nanog fluctuates and the cells are in a bivalent state
c. CHIR prevents the activity of GSK3 and this promotes self-renewal
d. All cells in the culture are in the ground state and express high levels of Nanog

Answer 24

b. The level of Nanog fluctuates and the cells are in a bivalent state

Question 25

• Oct4, Sox2 and Nanog have the capacity to regulate each other and themselves (autocrine).

Answer 25

T

Question 26

• All mouse ES cells in conventional culture express Oct4 and Nanog at stable levels.

Answer 26

F

Question 27

• ES cells maintain pluripotency at the ground state and become primed for a specific linage when they become progenitor cells.

Answer 27

T

Question 28

• LIF activates self-renewal and blocks differentiation.

Answer 28

T

Question 29

What happens during late reprogramming of iPS cells? a. Mesenchymal epithelial transition b. Retroviral vectors are expressed c. Somatic genes are hypermethylated d. Chromatin remodelling complexes are recruited

Answer 29

c. Somatic genes are hypermethylated

Question 30

What happens during infection with Yamanaka Factors? a. During the random phase, endogenous Sox2 regulates the expression of Oct4 b. The ordered phase precedes the random phase and is critical in the regulation of Nanog and Oct4 c. The random activation of genes eventually leads to the activation of endogenous Sox2 which signals the transition to the ordered phase d. Exogenous Klf4 and c-Myc are essential for generating iPS cells and are active in the ordered phase

Answer 30

c. The random activation of genes eventually leads to the activation of endogenous Sox2 which signals the transition to the ordered phase

Question 31

``` Match the reprogramming factors to their role during the random phase Oct4 Klf4 c-Myc Sox2 ``` Endogenous causes late phase (ordered). Active chromatin state and activates Oct4 and Nanog (endogenous) Exogenous activates gene expression (recruits chromatin remodelling complexes and binds closed chromatin) Inhibit gene expression Histone acetylation, exogenous Oct4 and Sox2 can bind DNA

Answer 31

Oct4 Exogenous activates gene expression (recruits chromatin remodelling complexes and binds closed chromatin) Klf4 Inhibit gene expression c-Myc Histone acetylation, exogenous Oct4 and Sox2 can bind DNA Sox2 Endogenous causes late phase (ordered). Active chromatin state and activates Oct4 and Nanog (endogenous)

Question 32

How similar are human ES cell and iPS cells? a. ES cell and iPS cells only differ in their morphology and their overall gene expression b. iPS cells take a long time to make and ES cells require a human blastocyst to be derived from c. iPS and ES cells have a similar morphology and surface markers but iPS cells have shorter telomeres d. Gene and protein expression is always the same in iPS and ES cells

Answer 32

b. iPS cells take a long time to make and ES cells require a human blastocyst to be derived from

Question 33

What is FALSE about issues and alternative methods associated with cell transplantation therapies? a. Viral vectors integrate randomly into the host genome, therefore insertion mutagenesis is a concern b. RNA transcripts may trigger an immune response and often require several treatment rounds c. Transposons like piggyback and sleeping beauty are examples of non-viral delivery methods which can be excised d. Proteins tethered to proteins have a high efficiency but cannot facilitate transmembrane transport

Answer 33

d. Proteins tethered to proteins have a high efficiency but cannot facilitate transmembrane transport

Question 34

What is FALSE about the basal lamina? a. It connect the epithelium to the stroma and is made of three layers (lamina lucida, lamina densa, reticular lamina) b. It can aid in anchoring and structure as well as cellular processes such as migration and proliferation c. It has ECM proteins in the form of collagens and proteoglycans only d. Cells are usually attached via hemidesmosones

Answer 34

c. It has ECM proteins in the form of collagens and proteoglycans only

Question 35

What can be shown by basal lamina directed gene expression in the mammary gland? a. Mammary epithelial cells grown on plastic express cell division genes such as c-myc and cyclinD1 b. The presence of a BL encourages mammary epithelial cells to divide more and stop the expression of p21 c. When grown on BL, mammary epithelial cells lose the ability to express mammary gland specific genes like lactoferrin, casein and WAP d. Mammary epithelial cells grown on plastic express mammary-gland specific genes such as lactoferrin and casein

Answer 35

a. Mammary epithelial cells grown on plastic express cell division genes such as c-myc and cyclinD1

Question 36

• iPS cells demonstrate chimerism and germ line transmission but not tetraploid complementation.

Answer 36

F

Question 37

• iPS cells can be generated using any differentiated cell.

Answer 37

T

Question 38

• Exogenous Oct4 and Sox2 are essential in generating iPS cells.

Answer 38

T

Question 39

• The stem cell niche is defined solely by location.

Answer 39

F

Question 40

• In healthy cells (non-cancerous), proliferation and differentiation and mutually exclusive.

Answer 40

T

Question 41

• Embryonic Germ Cells (EG) are derived from undifferentiated cells in teratocarcinoma and Embryonal Carcinoma Cells (EC) are derived from primordial germ cells (pluripotent).

Answer 41

F

Question 42

What is not a feature of an adult stem cell? a. Self-renewal b. Short life span c. Multipotent d. Found amongst differentiated cells

Answer 42

b. Short life span

Question 43

Which is the correct order of renewal capacities? a. liver/muscle > bone marrow > epidermis > nervous tissue b. epidermis bone> marrow > nervous tissue > liver/muscle c. bone marrow > epidermis > liver/muscle > nervous tissue d. nervous tissue> liver/muscle > epidermis > bone marrow

Answer 43

c. bone marrow > epidermis > liver/muscle > nervous tissue

Question 44

What is false about the processes underlying the fate determinants of daughter stem cells? a. Independent choice can lead to two stem cells, terminally differentiated cell and stem cell or two terminally differentiated cells which all make up a pool of stem cells b. Asymmetric division is influenced by determinants which localise on one side of a cell/plane c. Haematopoietic stem cells demonstrate asymmetric division due to their reliance on the positioning of stromal cells d. Neuroblasts commonly undergo asymmetric division

Answer 44

c. Haematopoietic stem cells demonstrate asymmetric division due to their reliance on the positioning of stromal cells

Question 45

Which best describes an aspect of morphollaxis or epimorphosis? a. Epimorphosis is seen in simple animals like worms and is the re-patterning and re-establishment of boundaries b. Morphollaxis can be seen in newts and involves new growth and correct patterning c. In morphollaxis, positional values are independent of boundary regions d. In epimorphosis, new positional values are linked to growth from the cut surface

Answer 45

d. In epimorphosis, new positional values are linked to growth from the cut surface

Question 46

What is false about the blastema? a. It is made up of natural iPS cells b. It contains de-differentiated cells in a heterogeneous collection c. Cells cannot proliferate in it in the absence of nerve cells d. Cells in the blastema can retain their specification even though they de-differentiate

Answer 46

a. It is made up of natural iPS cells

Question 47

• Asymmetric division is due to a determinant on one side of a plane whilst independent choice is stochastic.

Answer 47

T

Question 48

• Stem cells are shorter lived than all other cells in the intestine.

Answer 48

F

Question 49

• Satellite cells are quiescent stem cells.

Answer 49

T

Question 50

• In the Blastema, cells fully revert to pluripotency.

Answer 50

F

Question 51

• Salamander limbs can still regenerate when nerves are damaged.

Answer 51

F

Question 52

• nAG can bind to Prod1 and lead to limb regeneration when nerves are dysfunctional.

Answer 52

T