12. Respiration
A section of Biology, 0610
Listing 10 of 234 questions
Define the term respiration. A rowing machine is a piece of apparatus that is used in many fitness centres. shows a man training on a rowing machine. The man in the photograph has his arms extended during the rowing stroke as shown in . Use to describe how the hand is moved closer to the chest during the rowing stroke. The man has an intense workout on the rowing machine. shows his oxygen uptake before and during the exercise. 0.0 0.5 oxygen consumption / dm3 min–1 1.0 1.5 2.0 2.5 3.0 time / min exercise starts exercise ends Explain why there is a steep increase in the man’s oxygen consumption at the start of the exercise. It took 10 minutes after the man had stopped rowing for his oxygen consumption to decrease to its resting value. On draw a line between 20 minutes and 35 minutes to show the change in oxygen consumption after exercise has stopped. Explain why the man’s oxygen consumption did not return to the resting value immediately after exercise.
0610_s14_qp_31
THEORY
2014
Paper 3, Variant 1
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A scientist monitored the changes in the pH in muscles before, during and after two minutes of vigorous exercise. The changes in pH are caused by the production of lactic acid. 6.40 6.50 6.60 6.70 6.80 6.90 7.00 7.10 vigorous exercise time / minutes pH in muscles Complete the sentences to describe and explain the results in . The pH decreases from to during vigorous exercise. There is not enough supplied to the muscles. The body respires anaerobically. The lactic acid produced builds up in the muscles causing an debt. It takes minutes for the muscle pH to return to its initial level after exercise. The pH value increases after vigorous exercise has ended, as lactic acid is transported in the to the . During this time the breathing rate and rate remain high. Yeast can respire anaerobically. Complete the balanced chemical equation for anaerobic respiration in yeast. C6H12O6 Yeast belongs to the kingdom fungus. State one cell component that is present in yeast cells but is absent in animal cells.
0610_s23_qp_41
THEORY
2023
Paper 4, Variant 1
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For Examiner's Use In the space below write a balanced chemical equation for anaerobic respiration in muscles. …….…………………….………  ………………… … ………… Some students investigated the breathing of a 16-year old male athlete. shows the pattern of his breathing for 60 seconds when resting. shows the pattern of his breathing while he took some exercise for 60 seconds. time / s volume of air / dm3 time / s volume of air / dm3 For Examiner's Use Table 3.1 shows a summary of the results obtained by the students. Table 3.1 breathing at rest breathing during exercise volume of air breathed in with each breath / dm3 0.5 …………………………… rate of breathing / number of breaths per minute …………………………… volume of air breathed in per minute / dm3 5.5 …………………………… Using information from , complete Table 3.1. Write your answers in Table 3.1. Explain the effect of exercise on the student’s breathing. For Examiner's Use During strenuous exercise, the hormone adrenaline causes changes in the pulse rate and in the concentration of glucose in the blood. Explain the importance of these changes during strenuous exercise. pulse rate concentration of glucose in the blood
0610_w10_qp_32
THEORY
2010
Paper 3, Variant 2
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Sports physiologists study ways in which athletes can improve their performance by recording factors such as oxygen uptake and the concentration of lactic acid in the blood. They can also monitor how these two factors change during training. shows an athlete running on a treadmill in a physiology laboratory while aspects of his breathing are measured. . The athlete ran on a treadmill at a slow speed for 11 minutes. His oxygen uptake was measured before, during and after the exercise. The results are shown in . The arrows indicate the start and end of the period of exercise. State the oxygen uptake at rest, before the athlete started running. cm3 kg–1 min–1 Use to describe the changes in oxygen uptake during and after running on the treadmill (from 2 to 25 minutes). Content removed due to copyright restrictions. Explain the change in oxygen uptake during the run (between 2 and 13 minutes). The lactic acid concentration in the blood of the athlete was measured at intervals. At the end of the slow run the lactic acid concentration had increased by 30%. After a rest, the athlete ran at a much faster speed on the treadmill. At the beginning of this exercise the lactic acid concentration in his blood was 100 mg dm–3. After 11 minutes running at the faster speed, his lactic acid concentration was 270 mg dm–3. Calculate the percentage increase in lactic acid concentration at the end of the faster run. Show your working. answer % Explain why the percentage increase in lactic acid is much greater when running at the faster speed.
0610_w15_qp_32
THEORY
2015
Paper 3, Variant 2
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Questions Discovered
234