Exam practice
Exam questions
Write your answer. Then open the mark scheme and tick each point you made.
- Question 1 of 111 mark
Name the part of a cell where aerobic respiration happens.
Mark scheme
- Mitochondria (accept: mitochondrion)
- Question 2 of 112 marks
Describe the difference between breathing and respiration.
Mark scheme
- Breathing is moving air into and out of the lungs
- Respiration is a chemical reaction in cells that releases energy
- Question 3 of 112 marks
Write the word equation for aerobic respiration.
Mark scheme
- Reactants: glucose + oxygen (in either order)
- Products: carbon dioxide + water (in either order)
- Question 4 of 112 marks
Give two things that the body uses the energy from respiration for.
Mark scheme
- Any one from: movement (accept: making muscles contract), keeping warm, growth or repair (accept: building new molecules)
- A second one from the same list (accept any other correct use)
- Question 5 of 112 marks
State when muscle cells respire anaerobically, and name the substance that is made.
Mark scheme
- During hard exercise (accept: when they cannot get enough oxygen)
- Lactic acid
- Question 6 of 112 marks
A sprinter keeps breathing hard for several minutes after a race. Explain why.
Mark scheme
- Lactic acid has built up in the muscles
- Extra oxygen is needed to break it down (accept: to pay back the oxygen debt)
- Question 7 of 112 marks
Write the word equation for fermentation in yeast.
Mark scheme
- Reactant: glucose
- Products: ethanol + carbon dioxide (in either order)
- Question 8 of 112 marks
Give two uses of fermentation by yeast.
Mark scheme
- Making bread (accept: baking)
- Brewing (accept: making beer or wine)
- Question 9 of 112 marks
A baker mixes yeast into bread dough and leaves the dough in a warm place. Explain why the dough rises.
Mark scheme
- The yeast respires (accept: ferments the sugar) and makes carbon dioxide
- The gas is trapped as bubbles, which make the dough swell
- Question 10 of 112 marks
A student puts yeast and glucose solution into two flasks and stretches a balloon over the neck of each. One flask is kept at 10 °C and the other at 35 °C. After 20 minutes, the balloon on the warm flask is much bigger. Name the gas in the balloons and explain the result.
Mark scheme
- Carbon dioxide
- The warm yeast ferments (accept: respires) faster, so it makes the gas faster
- Question 11 of 113 marks
Compare aerobic respiration with anaerobic respiration in human muscles. Give one similarity and two differences.
Mark scheme
- Similarity: both use glucose, or both release energy
- Difference: aerobic respiration uses oxygen and anaerobic respiration does not
- Difference: aerobic respiration releases more energy, or aerobic respiration makes carbon dioxide and water and anaerobic respiration makes lactic acid