AIPMT MAINS 2011 Botany Cell Biology MCQ Question
The figure below shows the structure of a mitochondrion with its four parts labelled (A), (B), (C) and (D). Select the part correctly matched with its function.
Part (C) : Cristae – possess single circular DNA molecule and ribosomes
Part (A) : Matrix – major site for respiratory chain enzymes
Part (D) : Outer membrane – gives rise to inner membrane by splitting
Part (B) : Inner membrane – forms infoldings called cristae
Correct Answer
Detailed Explanation
Explanation
(A) 🔴 ✗ Incorrect Cristae are folds of the inner membrane. Mitochondrial DNA and ribosomes are present in the matrix, not in cristae.
(B) 🔴 ✗ Incorrect The respiratory chain is located on the inner mitochondrial membrane, not in the matrix.
(C) 🔴 ✗ Incorrect The outer membrane does not give rise to the inner membrane by splitting. The inner membrane independently forms folds called cristae.
(D) 🟢 ✓ Correct The inner mitochondrial membrane forms infoldings called cristae, which increase the surface area for ATP production.
⚡ Quick Revision
- Matrix → mtDNA + ribosomes + Krebs’ cycle
- Inner membrane → Respiratory chain + ATP synthase
- Cristae → Infoldings of inner membrane
- Outer membrane → Outer boundary of mitochondrion
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