GCSE Combined Science Bioenergetics questions by topic

Write out and label the two bioenergetics equations.

1. (a)Write the word equation for photosynthesis.[2]
2. (b)Write the word equation for aerobic respiration.[2]

Name the fate of glucose in each situation.

1. (a)A plant banks energy for overnight use.[1]
2. (b)A seed is packed with energy for germination.[1]
3. (c)A shoot builds new cell walls.[1]
4. (d)A leaf cell needs energy right now.[1]

This question is about the pondweed practical.

1. (a)State what is measured to compare the rate of photosynthesis.[1]
2. (b)State the independent variable.[1]
3. (c)Name two variables that must be controlled.[2]

Describe what happens to a sprinter’s breathing and heartbeat during a 100 m race.

1. (a)State two changes in the sprinter’s body during the race.[2]
2. (b)Explain why each change happens.[2]

A pondweed shoot gives the bubble counts below.

1. (a)Calculate the mean rate at each distance.[2]
2. (b)Use the inverse-square law to predict the relative intensity at 20 cm compared with 10 cm.[1]
3. (c)Comment on whether the data supports the inverse-square prediction.[1]

A greenhouse grower supplies extra carbon dioxide and brighter lamps but forgets to heat the glasshouse in spring.

1. (a)Identify the limiting factor on a cold morning and explain why.[2]
2. (b)State what the grower should change and the likely effect.[2]

This question contrasts the two respiration pathways a working muscle can use.

1. (a)Give the word equation for each.[2]
2. (b)Compare the energy released.[1]
3. (c)Explain when the body switches to the anaerobic pathway.[2]

A runner’s recovery data are shown.

1. (a)Describe the trend in the data.[1]
2. (b)Explain why the heart rate stays high after the run.[2]
3. (c)Name the substance being cleared.[1]

A horticulture business grows lettuce in glasshouses with lamps and carbon dioxide injection.

1. (a)Explain how each of the two interventions raises the photosynthesis rate.[2]
2. (b)Explain why a paraffin burner is sometimes used instead of gas cylinders.[2]
3. (c)Give one economic factor the grower must weigh before adding more equipment.[2]

Evaluate the pondweed bubble-count method against a gas-syringe method.

1. (a)Give one advantage of the bubble count.[1]
2. (b)Give two limitations of counting bubbles.[2]
3. (c)Explain why a gas syringe gives better data.[2]

A student claims: “Plants respire only at night.”

1. (a)State whether the claim is correct.[1]
2. (b)Explain the truth about respiration and photosynthesis across a 24-hour day.[3]
3. (c)Explain why a plant still grows slowly in midwinter even on bright days.[2]

Design an investigation to find the effect of carbon dioxide concentration on the photosynthesis rate of pondweed.

1. (a)State how the carbon dioxide concentration would be changed and measured.[2]
2. (b)State two variables you would hold constant and how.[2]