Question Constellation Sign up for free AQA · GCSE · Biology · Higher
Reduced Oxygen and Respiration
CF reduces the amount of oxygen that can enter the blood from the alveoli.
Explain how a reduced amount of oxygen entering the blood will affect the human body.
Write your answer first. You can study the marking guidance whenever you need it.
Study the marking See what earns credit and compare it with a full-mark answer.
Marking points
- 1 Links reduced oxygen to less aerobic respiration or more anaerobic respiration.
- 2 States either that less energy is released or that lactic acid is produced, consistently with the chosen route.
- 3 Gives a valid linked consequence for muscles, metabolism, breathing or heart rate.
Full-mark answer
With less oxygen, cells carry out less aerobic respiration, so less energy is released. This can reduce muscle contraction and metabolism and can make the person breathe faster or increase their heart rate to compensate.
Why this answer loses marks
Less oxygen means the body produces less energy.
Credit requires energy to be released, then linked to a body effect; 'produces energy' is not accepted.