An active athlete has more stamina of running compared to an officer of same age with physically inactive lifestyle. Which of the following organelles has greatly increased in the muscle cells of athlete?
Correct answer: B. Mitochondria
- A. Nucleus
- B. Mitochondria
- C. Golgi bodies
- D. Smooth endoplasmic reticulum (SER)
Explanation
Endurance training increases the number and size of mitochondria in muscle fibres, so more ATP can be produced aerobically and the athlete relies less on anaerobic respiration and accumulates lactate more slowly. This is one of the main measurable adaptations to training. The number of nuclei and the extent of the Golgi are not what limits stamina.
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About Cellular Respiration
Cellular respiration releases energy from glucose through glycolysis, the link reaction, the Krebs cycle and the electron transport chain, producing ATP. The pathway differs in oxygen availability: aerobic respiration uses oxygen and yields more ATP, while anaerobic respiration produces much less ATP and forms lactic acid in muscles or ethanol and carbon dioxide in yeast.
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