Stem Cells

Question 1

What are the two defining properties of stem cells?

Answer 1

1.) Self-renewal
2.) Differentiation into specialized cell types

Question 2

Differentiate totipotent, pluripotent, and multipotent stem cells

Answer 2

Totipotent: Can form embryo + placenta (zygote)
Pluripotent: All body cell types (embryonic stem cells)
Multipotent: Restricted lineages (blood, neural, mesenchymal)

Question 3

What drives differentiation at the molecular level?

Answer 3

Changes in gene expression controlled by transcription factors and epigenetic modifications

Question 4

Why do salamanders regenerate limbs easily but humans cannot?

Answer 4

Salamanders retain highly potent, plastic adult stem cells; humans’ are more lineage-restricted

Question 5

What are induced pluripotent stem cells (iPSCs)?

Answer 5

Adult cells reprogrammed to a pluripotent state by forced expression of key transcription factors

Question 6

Give one medical use of stem cells

Answer 6

Bone marrow transplants, skin grafts, regenerative therapies

Question 7

How does physical environment affect stem cell fate?

Answer 7

Mechanical stiffness, extracellular matrix, and chemical cues bias differentiation (e.g., soft → neurons; stiff → bone)

Question 8

What is a stem cell?

Answer 8

A cell that can self-renew and differentiate into one or more cell types

Question 9

Define potency

Answer 9

The range of cell types a stem cell can become

Question 10

What is differentiation?

Answer 10

The process of becoming a specialized cell type via transcription factor–driven gene expression changes

Question 11

What is proliferation?

Answer 11

Cell division leading to increased cell number

Question 12

What molecules control differentiation?

Answer 12

Transcription factors and gene expression programs

Question 13

Why does potency decrease during development?

Answer 13

Lineage-specific transcription factors turn on while others turn off, restricting cell fates

Question 14

Where do embryonic stem cells come from?

Answer 14

The inner cell mass of the blastocyst

Question 15

Which stem cells are multipotent?

Answer 15

Adult stem cells

Question 16

Which stem cells are pluripotent?

Answer 16

Embryonic stem cells (ESCs) and iPS cells

Question 17

What is the function of adult stem cells?

Answer 17

Tissue maintenance and repair

Question 18

What are iPS cells?

Answer 18

Somatic cells reprogrammed to pluripotency using transcription factors

Question 19

Give one application of iPS cells in the lab

Answer 19

Disease modeling; drug screening; differentiation into specialized cell types

Question 20

Why combine iPS cells and CRISPR?

Answer 20

To create corrected, patient-specific therapeutic cells with no immune rejection

Question 20

How can CRISPR be used with iPS cells for disease modeling?

Answer 20

Create isogenic pairs differing only by one mutation

Question 21

What is a major risk of using pluripotent cells therapeutically?

Answer 21

tumor formation

Question 22

Why might adult stem cells be harder to use in therapy?

Answer 22

Limited potency and low numbers

Question 23

What is a major challenge for all stem cell therapies?

Answer 23

Ensuring transplanted cells integrate and function properly