COMPETITIVE EXAM MCQs SERIES of LIFE SCIENCES for CSIR-UGC NET/JRF, SLET, GATE, and other entrance tests: DEVELOPMENTAL BIOLOGY – Basic Concepts of Developmental Biology.
Syllabus Outline
- Potency, commitment, specification, induction, competence, determination and differentiation.
- Morphogenetic gradients, cell fate and cell lineages.
- Stem cells, genomic equivalence and the cytoplasmic determinants.
- Imprinting, mutants and transgenics in the analysis of development.
This quiz contains 25 concept-based, most frequently asked MCQs on “DEVELOPMENTAL BIOLOGY – Basic Concepts of Developmental Biology”. Each question has a single correct/most appropriate answer.
*****
1. In a classical experiment, cytoplasm from the vegetal pole of a frog egg is transplanted into the animal pole of another embryo, leading to the formation of endodermal tissues at the new location. This indicates:
A) Nuclear equivalence is absent
B) Determination is irreversible at early stages
C) Inductive signals are independent of cytoplasm
D) Cytoplasmic determinants influence cell fate
2. Which of the following best describes the property of “competence” in developmental induction?
A) The ability of a tissue to produce a signalling molecule.
B) The ability of a cell to differentiate in a neutral environment.
C) The ability of a tissue to respond to a specific inductive signal.
D) The irreversible commitment of a cell to a specific lineage.
3. A morphogen gradient of Sonic hedgehog is responsible for specifying neuron types in the ventral neural tube. If the notochord is removed, what is the most likely result?
A) All ventral neurons will still form correctly.
B) Ventral neuron types will fail to differentiate.
C) The neural tube will fail to close.
D) The entire neural tube will adopt a ventral identity.
4. In mammalian cloning, the birth of “Dolly” the sheep demonstrated that:
A) Mammary cells are naturally pluripotent.
B) The cytoplasm of an adult mammary cell can be reprogrammed to a totipotent state.
C) The nucleus of an adult somatic cell can be reprogrammed to a totipotent state.
D) Cloning is possible using embryonic donor nuclei.
5. “Stem cell niches” are essential because they:
A) Provide a suitable microenvironment where a cell can undergo mitosis.
B) Provide a suitable microenvironment to protect stem cells from all forms of DNA damage.
C) Provide a microenvironment of signals that maintain stem cells in an undifferentiated state.
D) Provide a suitable microenvironment to stimulate stem cells to differentiate into multiple lineages.
6. The process by which a cell’s developmental potential becomes restricted to a specific fate, even if the environment changes, is called:
A) Specification.
B) Determination.
C) Differentiation.
D) Induction.
7. In the study of developmental mutants, a “homeotic mutation” is one that:
A) Causes the embryo to die early in cleavage.
B) Replacement of one body part with another.
C) Prevents the formation of any germ layers.
D) Increases the rate of cell division.
8. Which of the following statements about “cytoplasmic determinants” is FALSE?
A) They are often mRNA or protein molecules.
B) They are localised in specific regions of the egg or early embryo.
C) They are found in organisms that undergo regulative development.
D) They are partitioned into specific cells during cleavage.
9. A knockout of the Nanog gene in mice would primarily affect which stage of development?
A) Cleavage
B) Pluripotency
C) Organogenesis
D) Neurulation
10. The concept of Genomic Equivalence is challenged by which of the following biological processes?
A) Alternative splicing of mRNA.
B) V(D)J recombination in B and T lymphocytes.
C) Differential gene expression.
D) Epigenetic silencing by histone methylation.
11. If a cell is “specified” but not “determined,” and it is transplanted to a new region with different signals, it will:
A) Die.
B) Follow its original fate.
C) Alter its fate.
D) Revert to a totipotent state.
12. What is the effect of DNA methylation on genomic imprinting?
A) It serves as the epigenetic mark that activates one of the parental genes
B) It serves as the epigenetic mark that silences one of the parental alleles.
C) It serves as the epigenetic mark that increases the rate of DNA replication.
D) It does not affect gene expression.
13. In the tunicate embryo, the Macho-1 mRNA is a cytoplasmic determinant for:
A) Neural tissue.
B) Muscle tissue.
C) Gut tissue.
D) Epidermis.
14. In Xenopus development, the Spemann-Mangold Organiser is responsible for:
A) Forming a second dorsal axis.
B) Forming the gut.
C) Producing the yolk.
D) Determining the sex of the frog.
15. An Induced Pluripotent Stem Cell is created by:
A) Injecting a somatic nucleus into an egg.
B) Introducing specific transcription factors into a differentiated adult cell.
C) Growing skin cells in a very high-salt medium.
D) Harvesting cells from a developing blastocyst.
16. If you transplant a blastomere from a “mosaic” embryo into a “regulative” embryo of the same stage:
A) It behaves autonomously.
B) It adapts to the new microenvironment.
C) It transfers to a stem cell.
D) It inhibits the host embryo.
17. In vertebrate limb development, Sonic hedgehog is produced by the:
A) Apical Ectodermal Ridge.
B) Neural Tube.
C) Progress Zone.
D) Zone of Polarising Activity.
18. Which of the following results from a transplantation experiment would indicate that a tissue is “determined”?
A) It forms its original tissue type.
B) It forms the tissue type of its new microenvironment.
C) It reverts to a blastula-like state.
D) It stops growing in a new microenvironment.
19. In the mammalian embryo, the first differentiation event occurs when:
A) The zygote divides into two cells.
B) The heart starts beating.
C) The three germ layers form.
D) The morula starts separating.
20. “Lateral Inhibition” is a mechanism where:
A) One cell inhibits its immediate neighbour from becoming exactly like itself.
B) One cell inhibits its immediate neighbours from adopting the same fate.
C) One cell inhibits the growth of neighbours.
D) Cells move sideways during gastrulation to prevent signals from the neighbours.
21. Which of the following is the hallmark of “Syncytial Specification”?
A) Interaction between nuclei in a common cytoplasm before cellularization.
B) Induction by a neighbouring cell’s membrane proteins before cellularization.
C) Localisation of determinants in the yolk.
D) Requirement for sperm entry to define the axis.
22. Which of the following statements are correct regarding embryonic induction?
I – Competence of responding tissue is temporally regulated
II – Inductive signals can only act during early cleavage stages
III – Induction often involves diffusible morphogens
IV – Once induced, tissues always remain plastic
A) I and III
B) I, II and III
C) II and IV
D) I and IV
23. Which of the following statements about stem cells are correct?
I – Embryonic stem cells are pluripotent
II – Stem cell niches regulate self-renewal
III – Induced pluripotent stem cells are generated by transcription factor reprogramming
IV – Adult stem cells are always multipotent
A) I Only
B) I and II
C) I, II and III
D) I, II, III and IV
24. Assertion (A): Morphogen gradients can specify multiple cell fates within a field of cells.
Reason (R): Cells interpret morphogen concentration thresholds to activate distinct gene expression programs.
A) Both A and R are true, and R correctly explains A
B) Both A and R are true, but R does not explain A
C) A is true, R is false
D) A is false, R is true
25. Assertion (A): The zygote is considered totipotent, whereas embryonic stem cells are considered pluripotent.
Reason (R): Zygotes can give rise to embryonic germ layer derivatives, while embryonic stem cells can give rise to all embryonic and extra-embryonic tissues.
A) Both A and R are true, and R is the correct explanation of A.
B) Both A and R are true, but R is not the correct explanation of A.
C) A is true, but R is false.
D) A is false, but R is true.
*****
Previous: Innate and Adaptive Immune System
Next:
References
- Michael Barresi and Scott Gilbert (2023). Developmental Biology, Oxford University Press, 13th Edition.
- Lincoln Taiz, Ian Max Møller, Angus Murphy, and Eduardo Zeiger (2022). Plant Physiology and Development, Oxford University Press, 7th Edition.
- Geoffrey Cooper and Kenneth Adams (2022). The Cell: A Molecular Approach, Oxford University Press, 9th Edition.
- Alberts, B., Johnson, A., Lewis, J., Morgan, D., Raff, M., Roberts, K., & Walter, P. (2014). Molecular Biology of the Cell, Garland Science, 4th Edition.
- Robert A Weinberg, Robert A. Weinberg (2006). The Biology of Cancer, Taylor & Francis, 1st Edition.
- Gupta, P.K. (2022). Cell and Molecular Biology, Rastogi Publications, 5th Edition.
🔗 Explore More MCQs:
