AQA A LEVEL RESPIRATION EXAM QUESTIONS WITH
ANSWERS VERIFIED.
Suggest the advantages of the change in blood flow in blood vessels during
exercise. [3 marks]
-more blood flow to muscles during exercise
-supplying more glucose and oxygen/ removing carbon dioxide/ lactic acid/ heat
-for high rate of respiration/ to meet increased demand for energy
Explain how microorganisms contributed to the increase in temperature during
processing of organic waste. [2 marks]
respiration produces heat
explain the advantage of showing the data using standard deviations rather than
ranges. [2 marks]
SD is spread of data around the mean
SD reduces the effect of anomalies
SD can be used to determine if difference in results is significant. not significant/ due to
chance/ not due to chance
aerobic respiration produces more ATP per molecule of glucose than aerobic
respiration. Explain why. [2 marks]
oxygen is terminal electron acceptor/ oxygen combines with electrons and protons
aerobic respiration oxidative phosphorylation
anaerobic respiration only glycolysis occurs
...After a number of days, this injection of antigen resulted in the myelin sheaths
in the mice being damaged. some cell bodies of neurones were also damaged.
Suggest how the injection of the antigen resulted in the myelin sheaths being
damaged. [3 marks]
,antigen stimulated immune response
antibodies produced/ B/T cells divide
antibodies attach myelin sheath
Suggest why having a large number of mitochondria with this unusual
ultrastructure could lead to neurone dying. [3 marks]
fewer Cristae
so less oxidative phosphorylation
so not enough ATP produced to keep neurones alive
...For the first 10 minutes, the tap attached to the tube A was left open and the
syringe from tube B was removed. Suggest three reasons why the apparatus was
left for 10 minutes. [3 marks]
1. equilibrium reached
2. allow for pressure change in apparatus
3. allow respiration rate of seeds to stabilise
//
suggest and explain why the chosen temperature was 20C for this experiment. 2
marks
optimum temperature for normal growth of seeds
optimum temperature for enzymes involved in respiration
during the experiment, the coloured liquid in the tubing moved towards tube B.
explain what caused this. [3 marks]
oxygen taken up/ used by seeds
CO2 given out is absorbed by KOH
so pressure in B decreases
, ...Mitochondrial disease often causes muscle weakness. use your knowledge of
respiration and muscle contraction to suggest explanations for this effect of MD.
[3 mark]
reduction in ATP production by aerobic respiration
less force generated because fewer actin and myosin interactions in muscle
fatigue caused by lactate from anaerobic respiration
suggest how the change in the anticodon of a tRNA leads to MD [3 marks]
change to tRNA leads to wrong amino acid being incorporated into protein
tertiary structure of protein changed
protein required for oxidative phosphorylation/ the Krebs cycle, so less/ no ATP made
if someone has MD, the concentration of lactate in their blood after exercise is
usually much higher than normal. suggest why. [3 marks]
mitochondria/ aerobic respiration not producing much ATP
With MD increased use of ATP supplied by increase in anaerobic respiration
more lactate produced and leaves muscles by diffusion
describe how acetyl coenzyme A is formed in the link reaction. [2 marks]
pyruvate is oxidised and decarboxylated
addition of coenzyme A
...Oxalocatate is the first substrate to bind with enzyme citrate synthase. This
induces a change in the enzyme, which enables the acetylcoenzyme A to bind.
Explain how oxalocetate enables the acetylcoenzyme A to then bind to the
enzyme. [2 marks]
ANSWERS VERIFIED.
Suggest the advantages of the change in blood flow in blood vessels during
exercise. [3 marks]
-more blood flow to muscles during exercise
-supplying more glucose and oxygen/ removing carbon dioxide/ lactic acid/ heat
-for high rate of respiration/ to meet increased demand for energy
Explain how microorganisms contributed to the increase in temperature during
processing of organic waste. [2 marks]
respiration produces heat
explain the advantage of showing the data using standard deviations rather than
ranges. [2 marks]
SD is spread of data around the mean
SD reduces the effect of anomalies
SD can be used to determine if difference in results is significant. not significant/ due to
chance/ not due to chance
aerobic respiration produces more ATP per molecule of glucose than aerobic
respiration. Explain why. [2 marks]
oxygen is terminal electron acceptor/ oxygen combines with electrons and protons
aerobic respiration oxidative phosphorylation
anaerobic respiration only glycolysis occurs
...After a number of days, this injection of antigen resulted in the myelin sheaths
in the mice being damaged. some cell bodies of neurones were also damaged.
Suggest how the injection of the antigen resulted in the myelin sheaths being
damaged. [3 marks]
,antigen stimulated immune response
antibodies produced/ B/T cells divide
antibodies attach myelin sheath
Suggest why having a large number of mitochondria with this unusual
ultrastructure could lead to neurone dying. [3 marks]
fewer Cristae
so less oxidative phosphorylation
so not enough ATP produced to keep neurones alive
...For the first 10 minutes, the tap attached to the tube A was left open and the
syringe from tube B was removed. Suggest three reasons why the apparatus was
left for 10 minutes. [3 marks]
1. equilibrium reached
2. allow for pressure change in apparatus
3. allow respiration rate of seeds to stabilise
//
suggest and explain why the chosen temperature was 20C for this experiment. 2
marks
optimum temperature for normal growth of seeds
optimum temperature for enzymes involved in respiration
during the experiment, the coloured liquid in the tubing moved towards tube B.
explain what caused this. [3 marks]
oxygen taken up/ used by seeds
CO2 given out is absorbed by KOH
so pressure in B decreases
, ...Mitochondrial disease often causes muscle weakness. use your knowledge of
respiration and muscle contraction to suggest explanations for this effect of MD.
[3 mark]
reduction in ATP production by aerobic respiration
less force generated because fewer actin and myosin interactions in muscle
fatigue caused by lactate from anaerobic respiration
suggest how the change in the anticodon of a tRNA leads to MD [3 marks]
change to tRNA leads to wrong amino acid being incorporated into protein
tertiary structure of protein changed
protein required for oxidative phosphorylation/ the Krebs cycle, so less/ no ATP made
if someone has MD, the concentration of lactate in their blood after exercise is
usually much higher than normal. suggest why. [3 marks]
mitochondria/ aerobic respiration not producing much ATP
With MD increased use of ATP supplied by increase in anaerobic respiration
more lactate produced and leaves muscles by diffusion
describe how acetyl coenzyme A is formed in the link reaction. [2 marks]
pyruvate is oxidised and decarboxylated
addition of coenzyme A
...Oxalocatate is the first substrate to bind with enzyme citrate synthase. This
induces a change in the enzyme, which enables the acetylcoenzyme A to bind.
Explain how oxalocetate enables the acetylcoenzyme A to then bind to the
enzyme. [2 marks]
