Respiration occurs in cells - Edexcel - GCSE Biology Combined Science - Question 2 - 2023 - Paper 2
Question 2
Respiration occurs in cells.
(a) Why do cells respire?
A to produce nitrogen
B to release oxygen
C to produce glucose
D to release energy
(b) An athlete runs ever... show full transcript
Worked Solution & Example Answer:Respiration occurs in cells - Edexcel - GCSE Biology Combined Science - Question 2 - 2023 - Paper 2
Step 1
Why do cells respire?
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Answer
Cells respire primarily to release energy. The correct answer is D: to release energy. This energy is crucial for various cellular processes, including growth, repair, and maintenance.
Step 2
Explain why the breathing rate of the athlete increases when running.
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Answer
The breathing rate of the athlete increases during running to supply more oxygen to the muscles. Increased physical activity heightens the demand for oxygen to facilitate aerobic respiration, which in turn produces ATP (adenosine triphosphate) for energy. Additionally, as the intensity of the exercise elevates, metabolic waste like carbon dioxide accumulates, triggering the respiratory center to enhance the breathing rate to expel this excess carbon dioxide.
Step 3
State two differences between aerobic respiration and anaerobic respiration.
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Answer
Difference 1: Aerobic respiration uses oxygen, whereas anaerobic respiration does not use oxygen.
Difference 2: Aerobic respiration releases more energy compared to anaerobic respiration, which releases less energy and results in the production of lactic acid as a byproduct.