6.1. Photosynthesis
A subsection of Biology, 0610, through 6. Plant nutrition
Listing 10 of 307 questions
For Examiner's Use A student set up the apparatus shown in to investigate the effect of carbon dioxide concentration on the rate of photosynthesis of a pond plant. The student used five similar pieces of pond plant and five different concentrations of sodium hydrogen carbonate (NaHCO3) solution, which provides the carbon dioxide. The student counted the number of bubbles produced by the pond plant over a period of five minutes. water bath thermometer pond plant movable lamp cm ruler sodium hydrogen carbonate solution stop-clock Explain how the student made sure that the results were due only to the change in carbon dioxide concentration. For Examiner's Use The student repeated the investigation at each concentration and calculated the rate of photosynthesis. The student’s results are shown in Table 3.1. Table 3.1 rate of photosynthesis / number of bubbles per minute carbon dioxide concentration / % 1st 2nd 3rd mean 0.1 0.2 0.3 0.4 0.5 Calculate the mean rate of photosynthesis when the carbon dioxide concentration was 0.2% and write your answer in the table. Plot the results from Table 3.1 on the axes below. Draw an appropriate line on the graph to show the relationship between carbon dioxide concentration and the rate of photosynthesis. 0.1 0.2 0.3 concentration of carbon dioxide / % 0.4 0.5 0.6 mean rate of photosynthesis / number of bubbles per minute For Examiner's Use Explain the effect of increasing carbon dioxide concentration on the rate of photosynthesis up to 0.4% as shown in your graph. Suggest the result that the student would get if a carbon dioxide concentration of 0.6% was used and explain your answer. result bubbles per minute explanation The student used tap water as the 0% carbon dioxide concentration. Explain why the student recorded some bubbles being produced.
0610_w09_qp_32
THEORY
2009
Paper 3, Variant 2
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Pepper plants can be grown in glasshouses, where extra light can be supplied from electric lamps. The amount of carbon dioxide in the air inside a glasshouse was measured on two different days, M and N. On one of these days the lamps could not be used, because there was no electricity. shows the amount of carbon dioxide in the air around the pepper plants on day M and day N. 0.00 06.00 12.00 time of day 18.00 24.00 amount of carbon dioxide in air / arbitrary units day N day M Name the process, used by plants, that removes carbon dioxide from the air. State the time of day by which the pepper plants had removed most of the carbon dioxide. Using the data from , explain how you know that there was no electricity on day M. The amount of carbon dioxide and the availability of light affect the growth of pepper plants. Suggest two other factors that affect the growth of pepper plants. The pepper grower wanted to find out whether the peppers he grew contained sugar and vitamin C. State two reasons why too much sugar can be harmful to humans. State one reason why humans need vitamin C in their diet.
0610_w13_qp_23
THEORY
2013
Paper 2, Variant 3
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A researcher carried out four experiments, A to D, to investigate the effect of light intensity on the rate of photosynthesis of cucumber plants. The experiments were carried out at two concentrations of carbon dioxide and at two temperatures. The results are shown in . Key × × × × × × × light intensity / arbitrary units rate of photosynthesis / arbitrary units A B C D CO2 / % temp / °C A B C D 0.13 0.13 0.03 0.03 Use the results in to identify the limiting factor for the rate of photosynthesis at the light intensities given in Table 5.1. Write your answers in Table 5.1. Table 5.1 experiment light intensity / arbitrary units limiting factor A B C D light intensity Define the term limiting factor. shows that providing plants with more carbon dioxide can increase the rate of photosynthesis. An investigation was carried out in China using crop residues and animal manure mixed together in composting units that were placed into a glasshouse containing crop plants. shows a composting unit in which decomposition takes place. grid crop residues and animal manure sponge carbon dioxide Suggest the reason for using a grid instead of a solid base for the composting unit. The sponge was soaked in sulfuric acid to remove any ammonia gas released by the decomposing material . Explain how the ammonia was produced. Two glasshouses were used in this investigation. One glasshouse contained composting units and the other did not. Each glasshouse contained the same number and type of crop plants. The concentration of carbon dioxide in both glasshouses was measured at midday. The results are shown in . carbon dioxide concentration / parts per million time / days × × × × × × × × × × × × × × with composting units no composting units State why a glasshouse without composting units was used in the investigation. Describe the results shown in . At the end of the investigation the crop plants were harvested and weighed. Table 5.2 gives the results. Table 5.2 crop plant mean fresh mass / g per plant no composting units composting units Chinese cabbage 115.7 355.8 celery 44.7 133.9 lettuce 95.5 349.4 Use the information in and in Table 5.2 to summarise the results of the study.
0610_w14_qp_33
THEORY
2014
Paper 3, Variant 3
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Define the term photosynthesis and outline one reason why it is important to ecosystems. Name the green substance that plants need for photosynthesis. Name the gas that plants need for photosynthesis. Name the gas that plants produce during photosynthesis. shows the apparatus a student used to investigate how light intensity affects photosynthesis. test-tube cm ruler bubbles of gas aquatic plant lamp The student placed an aquatic plant under a funnel in a beaker of water. During the investigation she placed the lamp at different distances from the aquatic plant. At each distance she counted how many bubbles the aquatic plant produced in one minute. The bubbles of gas were then collected in the test-tube. shows the results of her investigation. distance of the lamp from the aquatic plant / cm number of bubbles per minute Use to find the number of bubbles produced when the lamp was placed 10 cm from the aquatic plant. bubbles per minute Describe how the rate of photosynthesis is affected by the distance of the lamp from the aquatic plant. Predict the number of bubbles that would be produced if the lamp was placed 21 cm from the aquatic plant. bubbles per minute Another student placed the lamp 15 cm from the aquatic plant and kept it there. Although the light intensity stayed the same, the number of bubbles produced by the aquatic plant per minute decreased. Suggest an explanation for this.
0610_w16_qp_33
THEORY
2016
Paper 3, Variant 3
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Two pieces of an aquatic plant were placed into two different test-tubes, P and Q. Each test-tube contained hydrogencarbonate indicator and was sealed and kept at 20 °C. Test-tube P was kept in the light and test-tube Q was kept in the dark. The table shows the effect of carbon dioxide on the colour of the hydrogencarbonate indicator. less carbon dioxide more carbon dioxide dark red orange What would the colour of the indicator be after 12 hours?
0610_w17_qp_23
MCQ
2017
Paper 2, Variant 3
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Questions Discovered
307