Question

Programmed cell death is called :

• A. Necrosis
• B. Apoptosis
• C. Pyknosis
• D. Karyolysis

Hint:

Remember: Apoptosis = highly regulated, neat, "programmed" cell death; Necrosis = accidental, messy, uncontrolled cell death causing local tissue inflammation.

Answer 1

The Correct Option is B

Step 1: Understanding the Concept:
Cellular damage, development, and tissue remodeling can result in cell death. Cell death occurs through distinct physiological (regulated) or pathological (accidental) cellular pathways.

Step 2: Detailed Explanation:
Let us define and contrast the different terms associated with cell death:
1. Apoptosis (B): This is the physiological process of programmed cell death. It is a highly regulated, energy-dependent pathway where the cell actively participates in its own demise. It is crucial for embryo development (such as tail resorption in tadpoles), tissue homeostasis, and elimination of damaged or infected cells without causing inflammation. Thus, (B) is correct.
2. Necrosis (A): Accidental, unprogrammed cell death resulting from acute pathological injury (like physical trauma, hypoxia, or toxin exposure). It is characterized by cell swelling, rupture of the plasma membrane, and release of intracellular contents, triggering a local inflammatory response.
3. Pyknosis (C): The morphological condensation of chromatin in the nucleus of a dying cell, leading to nuclear shrinkage.
4. Karyolysis (D): The complete dissolution and fading of the chromatin of a dying cell due to enzymatic degradation by DNases.

Step 4: Final Answer:
Therefore, programmed cell death is called Apoptosis.