A student sets up two vacuum flasks. Flask X contains living germinating peas. Flask Y contains peas that have been boiled and cooled. A thermometer is placed in each flask. After 3 days the temperature in flask X has risen by 4 ∘C4\ ^\circ\text{C}4 ∘C. The temperature in flask Y has not changed. Which conclusion is supported by these results?
Respiration in the living peas is an exothermic reaction.
Boiled peas respire faster because their enzymes are heated.
Photosynthesis in the living peas released heat into the flask.
Heat from the room passed into flask X but not into flask Y.
113 exam-style questions on OCR GCSE Biology 1.3 Respiration, covering 1.3.1 Cellular respiration supplies ATP, 1.3.2 Aerobic and anaerobic respiration, 1.3.3 Sugars and carbohydrates, 1.3.4 Amino acids and proteins, and 1.3.5 Fatty acids and lipids. Each one has a worked solution and a mark scheme showing where the marks go.