Theory question 101
Respiration(a)(i) What is respiration? (ii) In a tabular form, state four differences between gaseous exchange and aerobic respiration.
(b)(i) Explain the term residual air. (ii) What is the importance of residual air to mammals?
(c) State four characteristic features associated with respiratory structures.
(d)(i) What is oxygen debt? (ii) Outline three activities that can result in oxygen debt.
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(a)(i) Respiration is the breakdown (oxidation) of food, mainly glucose, in living cells to release energy as ATP, with or without oxygen.
(ii) Table — Gaseous exchange: physical process / Aerobic respiration: chemical process; takes place at respiratory surfaces (outside cells) / inside cells (mitochondria); no energy released / energy released; no enzymes needed / enzymes needed; O2 taken in and CO2 given out / O2 used to oxidise glucose and CO2 and water produced.
(b)(i) Residual air is the volume of air (about 1.5 litres) that remains in the lungs even after the deepest possible breathing out.
(ii) It keeps the alveoli from collapsing; allows gaseous exchange to continue between breaths; mixes with fresh air.
(c) Any four: large surface area; thin walls (short diffusion distance); moist surface; rich blood supply (capillaries); well ventilated.
(d)(i) Oxygen debt is the extra oxygen needed after vigorous exercise to oxidise the lactic acid built up in muscles during anaerobic respiration.
(ii) Any three: sprinting/running a race; lifting heavy weights; climbing stairs or hills quickly; swimming fast; prolonged strenuous work or games.
Use a ruled table with matching rows in (a)(ii).