The newest 11 of 11 written questions. Open one to see it on the real paper.
Describe the effect of variation of wind speed on transpiration rate.
See it on the paper →Pond B is polluted with nitrate fertiliser, which increases the availability of nitrates in pond B. Explain the difference in concentration of dissolved oxygen between pond A and pond B.
See it on the paper →What happens to the rate of these processes in high humidity?
See it on the paper →Table 4.1 shows that between 14:00 and 18:00 hours the temperature and humidity of the environment changes. Explain how each of these changes can affect the rate of transpiration. Change in temperature Change in humidity
See it on the paper →The starting temperature of the water-bath was 30 °C. Suggest if temperature is a source of error in this investigation. Tick (3) the appropriate box. • temperature is not a source of error • temperature is a source of error Give a reason for your answer.
See it on the paper →Identify one other possible source of error in this investigation.
See it on the paper →Suggest if the results in Table 1.4 support the relationship in (a)(ii). Explain your answer.
See it on the paper →Identify one way the procedure in (b) is an improvement on the procedure in (a).
See it on the paper →Describe the relationship between temperature and the amount of water lost by the plant shoot.
See it on the paper →Explain why the student uses plants that are the same species.
See it on the paper →A plant loses water from its leaves through transpiration. A student states: A plant in humid air will lose less water than a plant in dry air. Plan an investigation to test whether this statement is correct. In your answer, include: • the apparatus needed, including a labelled diagram if you wish • a brief description...
See it on the paper →Strong responses provided a clear and precise explanation. Some weaker responses incorrectly assumed that the algae used up the oxygen. Candidates should be encouraged to make it clear in their responses that it is the respiration of decomposers that uses the oxygen not just the process of decomposition. Some candidates assumed that the nitrates took up all the space leaving less room for the oxyg...
— Examiner report, October/November 2023, 0653/43 Q7(b)(ii) (Cambridge)
Candidates had to avoid answers which discussed the reverse argument for one or both conditions of temperature and humidity. Between 14:00 and 18:00 the temperature decreases and the humidity increases. Candidates had to state that both changes in conditions causes the rate of transpiration to decrease. Answers that stated when the temperature increases the rate of transpiration increases were not...
— Examiner report, May/June 2023, 0653/43 Q4(b)(ii) (Cambridge)
It was correct to say that temperature was not a source of error, because all the test tubes were in the same water bath. Answers that suggested that temperature was a source of error because the water bath cooled during the experiment were also accepted. Many candidates stated one of these ideas, but it was common for candidates to give vaguer answers such as “temperature is not controlled” or “t...
— Examiner report, February/March 2023, 0653/62 Q1(a)(v) (Cambridge)
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