CIE iGCSE Co-Ordinated Science B12. Respiration Exam Style Questions Paper 2
Question
A student places a mixture of yeast and glucose in a boiling tube, as shown in the diagram. They cover the mixture with a layer of oil. A delivery tube is used to bubble gas produced by the yeast through limewater.
After 10 minutes, the limewater is milky.
Why does the limewater go milky?
(A) The yeast produces carbon dioxide by anaerobic respiration.
(B) The yeast produces lactic acid by anaerobic respiration.
(C) The yeast produces carbon dioxide by photosynthesis.
(D) The yeast produces oxygen by aerobic respiration.
▶️Answer/Explanation
Ans: A
Question
Which process releases the most energy?
(A) carbon dioxide + water → glucose + oxygen
(B) glucose + oxygen → carbon dioxide + water
(C) glucose → alcohol + carbon dioxide
(D) glucose → lactic acid
▶️Answer/Explanation
Ans: B
Question
Which substances are used and produced in aerobic respiration?
▶Answer/Explanation
Ans :B
Question
Aerobic respiration releases energy from nutrient molecules.
One molecule of glucose requires ……1…… molecules of oxygen. The reaction releases ……2……
molecules of carbon dioxide and ……3…… molecules of water.
Which row completes gaps 1, 2 and 3?
▶️Answer/Explanation
Ans: D