Introduction:
This collection of multiple-choice questions focuses on differentiation, developmental biology, and stem cell fundamentals tailored for M.Pharm students. The quiz consolidates core concepts such as potency and lineage commitment, embryonic development stages, stem cell types (embryonic, adult, induced pluripotent), key signalling pathways and transcription factors that govern cell fate, and experimental assays used to characterize stem cells. Questions emphasize mechanistic understanding relevant to pharmacological applications, regenerative medicine, and translational challenges including tumorigenicity and immune rejection. Use these MCQs to test retention, deepen comprehension of molecular controls of development, and prepare for exams or research discussions in Microbial and Cellular Biology (MPB102T).
Q1. Which transcription factor quartet was originally used by Yamanaka to reprogram somatic cells into induced pluripotent stem cells (iPSCs)?
- Oct4, Sox2, Klf4, c-Myc
- Oct4, Nanog, Gata6, Sox17
- Sox2, Nanog, Lin28, MyoD
- Gata4, Mef2c, Tbx5, Hand1
Correct Answer: Oct4, Sox2, Klf4, c-Myc
Q2. Which of the following best describes a totipotent cell?
- A cell that can form all embryonic and extraembryonic tissues including placenta
- A cell restricted to forming only ectodermal derivatives
- A cell capable of forming most adult tissues but not the placenta
- A differentiated cell that cannot divide further
Correct Answer: A cell that can form all embryonic and extraembryonic tissues including placenta
Q3. Which surface marker is most commonly associated with human hematopoietic stem cells (HSCs)?
- CD34
- CD45RO
- CD19
- SSEA-4
Correct Answer: CD34
Q4. Which signalling pathway is classically implicated in establishing dorsal-ventral patterning and acts via BMP gradients during early vertebrate development?
- Bone morphogenetic protein (BMP) pathway
- Notch pathway
- JAK/STAT pathway
- Hedgehog pathway
Correct Answer: Bone morphogenetic protein (BMP) pathway
Q5. Which assay is considered the gold standard for demonstrating pluripotency of human pluripotent stem cells by showing contribution to all three germ layers in vivo?
- Teratoma formation assay
- Colony-forming unit assay
- Comet assay
- Apoptosis TUNEL assay
Correct Answer: Teratoma formation assay
Q6. During gastrulation, which germ layer gives rise primarily to the liver and pancreas?
- Endoderm
- Ectoderm
- Mesoderm
- Trophoblast
Correct Answer: Endoderm
Q7. Which of the following describes asymmetric cell division in stem cells?
- Division producing one self-renewing stem cell and one differentiating progenitor
- Division producing two identical differentiated cells
- Division producing two pluripotent stem cells only
- Cell fusion between two distinct cell types
Correct Answer: Division producing one self-renewing stem cell and one differentiating progenitor
Q8. Which transcription factor trio is most frequently cited as core pluripotency regulators in embryonic stem cells?
- Oct4, Sox2, Nanog
- Gata4, FoxA2, HNF4α
- Myf5, MyoD, Myogenin
- Pax6, NeuroD, Brn3
Correct Answer: Oct4, Sox2, Nanog
Q9. In stem cell niches, which stromal factor is critical for maintaining mouse embryonic stem cell self-renewal in vitro?
- LIF (Leukemia inhibitory factor)
- TNF-α
- IL-1β
- IFN-γ
Correct Answer: LIF (Leukemia inhibitory factor)
Q10. Which surface antigen set is commonly used to identify human pluripotent stem cells in culture?
- SSEA-3, SSEA-4, TRA-1-60, TRA-1-81
- CD3, CD4, CD8, CD19
- Albumin, AFP, CK19, HNF1
- Desmin, MyoD, Myf5, Pax7
Correct Answer: SSEA-3, SSEA-4, TRA-1-60, TRA-1-81
Q11. Which morphogen is secreted and forms gradients that are essential for anterior-posterior patterning in many animals, including limb development?
- Sonic Hedgehog (Shh)
- EGF (Epidermal growth factor)
- Insulin
- Actin
Correct Answer: Sonic Hedgehog (Shh)
Q12. Epigenetic changes during differentiation typically include which of the following?
- DNA methylation and specific histone modifications that silence lineage-inappropriate genes
- Random genomic mutations that alter coding sequence of pluripotency genes
- Permanent loss of all non-coding RNAs
- Complete removal of histones from chromatin
Correct Answer: DNA methylation and specific histone modifications that silence lineage-inappropriate genes
Q13. Which type of stem cell therapy risk is primarily associated with residual undifferentiated pluripotent cells after transplantation?
- Tumorigenicity (teratoma formation)
- Allergic dermatitis
- Immediate bacterial infection
- Cardiac arrhythmia exclusively
Correct Answer: Tumorigenicity (teratoma formation)
Q14. During early vertebrate development, the primitive streak is critical for which process?
- Gastrulation and formation of mesoderm and definitive endoderm
- Neural crest cell migration only
- Placenta formation exclusively
- Final organ maturation during postnatal life
Correct Answer: Gastrulation and formation of mesoderm and definitive endoderm
Q15. Which experimental method is commonly used to direct differentiation of pluripotent stem cells toward a neural lineage in vitro?
- Dual-SMAD inhibition (blocking BMP and TGF-β signals)
- Addition of retinoic acid only without other factors
- High glucose culture medium alone
- Exposing cells to ultraviolet light intermittently
Correct Answer: Dual-SMAD inhibition (blocking BMP and TGF-β signals)
Q16. What is the defining feature of a multipotent stem cell compared to a pluripotent stem cell?
- Can differentiate into multiple cell types within a single germ layer but not all germ layers
- Can form all embryonic and extraembryonic tissues
- Is fully differentiated and cannot divide
- Has the ability to transdifferentiate into entirely unrelated species’ cells
Correct Answer: Can differentiate into multiple cell types within a single germ layer but not all germ layers
Q17. Notch signalling in development primarily influences which cellular decision?
- Binary cell fate choices and lateral inhibition
- Mitochondrial DNA replication rate
- Global chromosomal rearrangements
- Extracellular matrix mineralization exclusively
Correct Answer: Binary cell fate choices and lateral inhibition
Q18. Which feature distinguishes embryonic stem cells (ESCs) from induced pluripotent stem cells (iPSCs) experimentally?
- ESCs are derived from the inner cell mass of blastocysts, while iPSCs are reprogrammed from somatic cells
- ESCs cannot differentiate into ectoderm, while iPSCs can
- ESCs express Oct4 but iPSCs never express Oct4
- ESCs are immune to teratoma formation whereas iPSCs always form tumors
Correct Answer: ESCs are derived from the inner cell mass of blastocysts, while iPSCs are reprogrammed from somatic cells
Q19. Which molecule is a commonly used feeder-free culture supplement to support human pluripotent stem cell growth by activating FGF signalling?
- Basic fibroblast growth factor (bFGF/FGF2)
- Interferon-alpha
- Transforming growth factor beta 3 (TGF-β3) only
- Vitamin D
Correct Answer: Basic fibroblast growth factor (bFGF/FGF2)
Q20. In organogenesis, reciprocal epithelial–mesenchymal interactions primarily regulate which of the following?
- Branching morphogenesis, differentiation timing and organ patterning
- Only the secretion of serum proteins
- Immune cell antigen presentation exclusively
- Photosynthesis in plant tissues
Correct Answer: Branching morphogenesis, differentiation timing and organ patterning
