2.44B Net gas exchange in light and dark
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A leaf in bright light is placed in a sealed tube with red hydrogencarbonate indicator. What colour does the indicator become?
(1)Total for this question: 1 mark
2(g) GAS EXCHANGE · EXAM QUESTIONS
2.44B Net gas exchange in light and dark
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2.44B Net gas exchange in light and dark
Exam question
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A leaf in a sealed tube kept in the dark turns hydrogencarbonate indicator which colour?
(1)Total for this question: 1 mark
2.44B Net gas exchange in light and dark
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Three tubes of hydrogencarbonate indicator contain a leaf: one in bright light, one in dim light and one in the dark. Explain the expected colours.
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Total for this question: 3 marks
2.44B Net gas exchange in light and dark
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Explain why the tube with no leaf is included in a hydrogencarbonate indicator experiment.
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Total for this question: 2 marks
2.44B Net gas exchange in light and dark
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Suggest how a tube could be kept in dim light rather than total darkness.
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Total for this question: 2 marks
2.44B Net gas exchange in light and dark
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Explain why the tubes are placed equal distances from the lamp with a heat filter.
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Total for this question: 2 marks
2.44B Net gas exchange in light and dark
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Predict the indicator colour after an hour for a tube containing a woodlouse and a leaf in bright light. Explain.
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Total for this question: 2 marks
2.44B Net gas exchange in light and dark
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Explain why a leaf at night takes in oxygen even though it produces oxygen in the day.
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Total for this question: 2 marks
2.44B Net gas exchange in light and dark
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Describe what is meant by net gas exchange.
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Total for this question: 2 marks
2.44B Net gas exchange in light and dark
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Identify the indicator colour that shows (i) a high carbon dioxide concentration (ii) a low carbon dioxide concentration.
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Total for this question: 2 marks
2.44B Net gas exchange in light and dark
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Explain why a pond plant gives off bubbles of gas in sunlight but not at night.
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Total for this question: 2 marks
2.44B Net gas exchange in light and dark
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At the compensation point, which statement is true?
(1)Total for this question: 1 mark
2.44B Net gas exchange in light and dark
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A greenhouse grower switches on lamps at dusk. Explain the effect on net gas exchange of the crop.
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Total for this question: 3 marks
2.44B Net gas exchange in light and dark
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Describe how net carbon dioxide exchange of a leaf changes as light intensity increases from darkness.
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Total for this question: 2 marks
2.44B Net gas exchange in light and dark
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A leaf in bright light takes in 18 units of carbon dioxide per hour. In the dark the same leaf releases 4 units per hour. Assuming respiration is the same in the light, calculate the gross rate of carbon dioxide used in photosynthesis.
(2)units per hourTotal for this question: 2 marks