Biology
Photosynthesis and respiration — Topics 6 and 12
- 1.
Write the word equation for photosynthesis, and state the two limiting factors that most commonly reduce its rate on a cool, cloudy day.
[3 marks] · no calculator - 2.
Explain why plant leaves need stomata for both photosynthesis and respiration to occur efficiently.
[4 marks] · no calculator - 3.
Describe an investigation using a plant, sodium hydrogencarbonate solution, and light of varying distance to show that light intensity is a limiting factor of photosynthesis.
[4 marks] · no calculator - 4.
Write the word equation for aerobic respiration, and state one difference between aerobic and anaerobic respiration in terms of the products formed.
[3 marks] · no calculator - 5.
Explain the role of chlorophyll in photosynthesis, and state where in the plant cell it is located.
[3 marks] · no calculator - 6.
Describe the starch test used to determine whether a leaf has photosynthesised, and explain why the leaf must first be de-starched (destarched) before an investigation.
[4 marks] · no calculator - 7.
State three raw materials or conditions required for photosynthesis to occur.
[3 marks] · no calculator - 8.
Explain why increasing carbon dioxide concentration increases the rate of photosynthesis only up to a certain point, beyond which the rate no longer increases.
[3 marks] · no calculator - 9.
Describe the exchange of gases between a leaf and the atmosphere during the day, when both photosynthesis and respiration are occurring simultaneously.
[3 marks] · no calculator - 10.
Explain why, at night, a plant releases only carbon dioxide and no oxygen into the atmosphere, even though it produced oxygen during the day.
[2 marks] · no calculator - 11.
During vigorous exercise, muscle cells may not receive enough oxygen to meet their energy demands through aerobic respiration alone. Describe what happens in muscle cells under these conditions, and explain what is meant by 'oxygen debt'.
[4 marks] · no calculator - 12.
Yeast can respire anaerobically in a process called fermentation. Write the word equation for this process, and state one industrial use of yeast fermentation.
[3 marks] · no calculator - 13.
Describe an experiment using germinating seeds and limewater to show that respiration produces carbon dioxide, including a control needed to make the experiment valid.
[4 marks] · no calculator - 14.
Describe three features of a typical leaf that adapt it for efficient photosynthesis.
[3 marks] · no calculator - 15.
Describe how guard cells control the opening and closing of a stoma.
[3 marks] · no calculator - 16.
Explain why the rate of respiration increases as temperature rises from 10 °C to the optimum temperature, but decreases sharply above this optimum.
[3 marks] · no calculator - 17.
Describe how discs cut from a leaf can be used to investigate the rate of photosynthesis at different light intensities.
[4 marks] · no calculator - 18.
State what is meant by the 'compensation point' of a plant, in terms of the rates of photosynthesis and respiration.
[2 marks] · no calculator - 19.
State three uses that a plant makes of the glucose produced during photosynthesis.
[3 marks] · no calculator - 20.
A graph shows the rate of photosynthesis increasing steeply with light intensity at first, then levelling off (plateauing) at higher light intensities. Explain what is limiting the rate of photosynthesis in each of these two regions of the graph.
[3 marks] · no calculator - 21.
Compare photosynthesis and respiration in terms of the type of energy transfer involved and where each occurs within a plant cell.
[3 marks] · no calculator - 22.
Hydrogencarbonate indicator solution is red in atmospheric air, turns yellow in a higher concentration of carbon dioxide, and turns purple in a lower concentration of carbon dioxide. A test tube containing hydrogencarbonate indicator and a green plant is left in bright light for several hours. Predict and explain the colour change observed.
[3 marks] · no calculator - 23.
Explain why a person's breathing rate remains higher than normal for some time after they stop vigorous exercise.
[3 marks] · no calculator - 24.
Explain why respiration occurs continuously in every living cell, both day and night, while photosynthesis only occurs in green plant cells when light is available.
[3 marks] · no calculator - 25.
Explain the role of ATP as the immediate energy source in cells, linking it to the process of respiration.
[3 marks] · no calculator