UPSC Prelims 2001 Q125: Science & Technology – Biology
The cellular and molecular control of programmed cell death is known as
- (a) Apoptosis
- (b) Ageing
- (c) Degeneration
- (d) Necrosis
Answer: (a) Apoptosis
Explanation
Programmed cell death
| Term | Meaning |
|---|---|
| Apoptosis | Programmed cell death — orderly, gene-controlled self-destruction of cells |
| Necrosis | Accidental cell death from injury; causes inflammation |
| Ageing | Gradual decline of the body over time |
| Degeneration | General decline of tissue; not a specific programme |
Apoptosis is the cell's built-in, controlled 'suicide' programme. It shapes the body during development (for example, removing webbing between fingers) and removes damaged cells. Necrosis is uncontrolled death caused by injury.
Answer: (a) Apoptosis.
Why each option is right or wrong
- (a) CORRECT. Apoptosis is programmed cell death.
- (b) Incorrect. Ageing is a process of the whole body, not a cell-death programme.
- (c) Incorrect. Degeneration is a general decline, not a controlled programme.
- (d) Incorrect. Necrosis is accidental, uncontrolled cell death.
Key point
Nobel Prize in Medicine 2002 (Brenner, Horvitz, Sulston) was for the genetics of programmed cell death.
Remember
Programmed cell death = apoptosis.
Common mistakes
- Choosing necrosis, the other kind of cell death.
- Thinking 'ageing' is the cell-level term.
- Not knowing that apoptosis is gene-controlled.
Exam tip
Programmed and orderly = apoptosis; injury and inflammation = necrosis.
Sources
- NCERT Class XII — Biology, chapter 'Human Health and Disease' (cancer and cell control)
- Nobel Prize — Physiology or Medicine 2002: genetic regulation of organ development and programmed cell death