Apoptosis MCQ Quiz | Molecular Biology

Welcome to the Apoptosis Quiz for MBBS students. This quiz is designed to test your understanding of programmed cell death, a fundamental process in molecular biology. Covering the intrinsic and extrinsic pathways, key regulatory proteins like caspases and the Bcl-2 family, and its clinical relevance in diseases such as cancer and neurodegeneration, these 25 questions will challenge your core knowledge. Carefully evaluate each option before making your choice. After submitting, you will see your score and a detailed review of the correct and incorrect answers. For your revision, you can download a PDF document containing all the questions and their correct answers. Good luck!

1. What is the primary role of initiator caspases, such as Caspase-9, in the process of apoptosis?

2. The extrinsic pathway of apoptosis is initiated by the binding of ligands (e.g., FasL) to which family of receptors?

3. Which of the following is a key anti-apoptotic protein belonging to the Bcl-2 family that prevents mitochondrial outer membrane permeabilization?

4. The release of which molecule from the mitochondrial intermembrane space into the cytosol is considered a “point of no return” in the intrinsic apoptotic pathway?

5. What is the name of the large, wheel-shaped multi-protein complex formed in the intrinsic pathway that activates Procaspase-9?

6. Which of the following morphological features is a hallmark of apoptosis but is characteristically absent in necrosis?

7. Executioner caspases, such as Caspase-3, orchestrate the final stages of apoptosis by:

8. The p53 tumor suppressor protein can induce apoptosis in response to DNA damage primarily by acting as a:

9. Which of the following is a “BH3-only” pro-apoptotic member of the Bcl-2 family that acts as a sensor of cellular stress?

10. The Death-Inducing Signaling Complex (DISC) is formed during which pathway of apoptosis?

11. What is the primary mechanism of action for Inhibitors of Apoptosis Proteins (IAPs)?

12. “Membrane blebbing” during apoptosis is a direct consequence of:

13. In contrast to necrosis, the integrity of the plasma membrane during apoptosis typically:

14. The core components of the apoptosome are Apaf-1, Cytochrome c, and which other molecule in its inactive form?

15. Granzyme B, a serine protease released by cytotoxic T lymphocytes, can initiate apoptosis by directly activating:

16. The efficient and silent clearance of apoptotic bodies by phagocytes is a process known as:

17. A failure of apoptosis during embryonic development, specifically in the tissue between digits, can lead to which congenital anomaly?

18. In the extrinsic pathway, ligand binding to a death receptor leads to the recruitment of an adaptor protein (like FADD) which, in turn, recruits and activates:

19. DNA fragmentation into oligonucleosomal-length fragments is a result of executioner caspases cleaving which protein?

20. A common mechanism by which cancer cells evade apoptosis is through the overexpression of which protein?

21. The externalization of phosphatidylserine on the outer leaflet of the plasma membrane during apoptosis serves as an “eat-me” signal for:

22. Which of the following best describes the characteristic DNA fragmentation pattern observed in apoptosis when analyzed by gel electrophoresis?

23. The “Bcl-2 homology” (BH) domains (BH1, BH2, BH3, BH4) are structural motifs characteristic of which protein family central to apoptosis regulation?

24. The “crosstalk” between the extrinsic and intrinsic apoptotic pathways is primarily mediated by Caspase-8 cleaving which BH3-only protein?

25. Which of the following is NOT a typical feature of apoptosis?