RAS question
Mitochondria are called the 'powerhouse of the cell' because they:
Correct answer: (C) Produce ATP through cellular respiration.
Mitochondria are called the powerhouse of the cell because they produce ATP through cellular respiration.
Explanation
Mitochondria earn the label powerhouse of the cell because they generate most of the cell's supply of adenosine triphosphate, or ATP, through oxidative phosphorylation during cellular respiration. NCERT's Biology exemplar frames the same idea directly: the observation that supports calling mitochondria powerhouses is that mitochondria synthesise ATP. ATP is the cell's usable energy currency, so the organelle that produces it in large amounts is linked to energy supply rather than information storage, protein synthesis, or waste removal. The broader explanation also notes that mitochondria have their own maternally inherited mtDNA and are thought to have originated from ancient endosymbiotic bacteria, but the reason for the powerhouse tag is ATP production.
Why the other options are wrong
- (A) Genetic information is primarily stored in the nucleus, so this does not explain the powerhouse label for mitochondria.
- (B) Protein synthesis is primarily the function of ribosomes, whereas the powerhouse label refers to ATP production.
- (D) Cellular waste removal is handled by lysosomes, not by mitochondria's ATP-generating role.
Concept
This tests the basic cell-biology link between organelles and their functions, especially mitochondria and cellular respiration. It recurs in RAS because general science questions often ask for the functional reason behind a familiar biological term.