ASU BIO 351 Module 1 Test QUESTIONS AND ANSWERS

ASU BIO 351 Module 1 Test
QUESTIONS AND ANSWERS
2026 - 2027

PART 1: CELL FATE & DEVELOPMENTAL POTENTIAL

Q1. Which of the following terms describes the step at which cells become irreversibly committed to a
particular cell fate?

 A) Specification

 B) Determination

 C) Differentiation

 D) Induction

Correct Answer: B

Rationale: Determination is the irreversible commitment step where a cell's fate is fixed regardless of
environment. Specification is reversible, while differentiation is the actual expression of specialized
characteristics .



Q2. Which is the correct order of developmental steps leading to a specialized cell type?

 A) Differentiation → determination → specification

 B) Specification → determination → differentiation

 C) Determination → specification → differentiation

 D) Induction → differentiation → determination

Correct Answer: B

Rationale: Cells first become specified (reversible), then determined (irreversible), and finally
differentiate into specialized cell types expressing tissue-specific genes .



Q3. As cells move along the continuum from stem cell to differentiated cell, which correctly identifies
the properties of a determined cell?

,  A) Fate is reversible in a non-neutral environment

 B) Fate is irreversible

 C) Cannot differentiate under any condition

 D) Differentiates only in a neutral environment

Correct Answer: B

Rationale: A determined cell's fate is irreversible—it will differentiate into its committed cell type even
when placed in a different environment .



Q4. Which of the following best defines asymmetric cell division?

 A) Mitosis producing equal daughter cells with identical fates

 B) Mitosis producing unequal daughter cells that ensures stem cell self-renewal

 C) Cell division that occurs only in cancer cells

 D) Division that produces only differentiated cells

Correct Answer: B

Rationale: Asymmetric division generates one stem cell (self-renewal) and one progenitor cell,
maintaining the stem cell pool while producing differentiated progeny .



Q5. Which of the following are TRUE properties of embryonic stem (ES) cells?

 A) They are multipotent and will senesce after several divisions

 B) They are pluripotent and will self-renew indefinitely

 C) They are unipotent and differentiate immediately

 D) They are totipotent like a zygote

Correct Answer: B

Rationale: ES cells derived from the inner cell mass are pluripotent (can form all embryonic lineages)
and self-renew indefinitely in culture .



Q6. Pick the answer that BEST describes the potential of embryonic stem cells (ES cells).

 A) Totipotential

 B) Pluripotential

 C) Multipotential

,  D) Unipotential

Correct Answer: B

Rationale: ES cells are pluripotent, not totipotent—they can form all cell types of the body but not
extraembryonic tissues like the placenta .



Q7. What are the two types of specification?

 A) Intrinsic and extrinsic

 B) Autonomous and conditional

 C) Primary and secondary

 D) Direct and indirect

Correct Answer: B

Rationale: Autonomous specification relies on intrinsic factors from the parent cell, while conditional
specification depends on signals from surrounding cells .



Q8. In autonomous specification, cells achieve their fate by:

 A) Receiving signals from neighboring cells

 B) Factors received from parent cells without external signals

 C) Environmental induction

 D) Random chance

Correct Answer: B

Rationale: In autonomous specification (mosaic development), cell fate is determined by cytoplasmic
determinants inherited from the parent cell, as seen in snail trochoblast cells .



Q9. The diagram shows a nematode embryo at the four cell stage. The EMS cell normally gives rise to
mesoderm and endoderm. Killing the P2 cells leads to disruption of EMS cell differentiation. What
process does this describe?

 A) Autonomous specification

 B) Conditional specification of the EMS cell

 C) Juxtacrine signaling

 D) Paracrine signaling

, Correct Answer: B

Rationale: The EMS cell requires signals from the P2 cell to specify its fate—this is conditional
(regulative) specification, where cell-cell interactions determine fate .



Q10. What would skin fibroblasts become if you induced expression of Oct4 (Pou5tf), Myc, Klf4, and
Sox2?

 A) Cancer cells

 B) Induced pluripotent stem cells (iPSCs)

 C) Neurons

 D) Muscle cells

Correct Answer: B

Rationale: These four Yamanaka factors reprogram somatic cells into induced pluripotent stem cells
(iPSCs), which resemble embryonic stem cells in pluripotency .



Q11. If you took a fibroblast and increased expression of Oct4, Myc, Klf4, and Sox2, you would convert
them into cells with differentiation potential most similar to:

 A) Epiblast

 B) Satellite Cells

 C) Neural Plate Cells

 D) Somites

 E) Zygote

Correct Answer: A

Rationale: iPSCs are pluripotent, similar to the epiblast (which gives rise to all three germ layers), but
not totipotent like a zygote .



Q12. Which of the following best describes the most important properties of the Yamanaka factors for
iPSC generation?

 A) Tumor suppressors

 B) Pioneering transcription factors expressed in ES cells

 C) Cell surface receptors

 D) Apoptosis regulators