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(a) Describe how the student could use this procedure to find the water potential of the plant storage tissue that has coloured cell sap.
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(b) (i) Suggest suitable units for the rate of movement of the drop.
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(ii) State how the student would estimate the water potential of the plant tissue.
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(c) (i) Identify the independent and dependent variables in this investigation.
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(ii) Identify two variables which the student may not have adequately controlled during the investigation.
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(iii) State how one of the variables you have identified in (c)(ii) may have influenced the results.
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(d) The student made direct observations of the cells of the tissues that had been immersed in $0.2 \text{mol} \ \text{dm}^{-3}$ and $0.8 \text{mol} \ \text{dm}^{-3}$ sucrose solutions.
(i) Predict the appearance of the cells under the microscope when immersed in
$0.2 \text{mol} \ \text{dm}^{-3}$ sucrose solution ......................................................................................................
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$0.8 \text{mol} \ \text{dm}^{-3}$ sucrose solution ......................................................................................................
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Use the space below for any diagrams you include in your answer to (i).
(ii) Explain your answers to (d)(i).
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500
512
546
(a) (i) Suggest why the mice were treated with FSH before the ovaries were removed.
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(a) (ii) Suggest the purpose of keeping the oocytes in a medium that maintains them at the primary oocyte stage.
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(b) Explain what $S_M$ shows about the mean percentage values.
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(c) (i) State the null hypothesis for these tests.
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(c) (ii) State a statistical test that could be used and give the reason for your choice.
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(c) (iii) The result of the statistical test comparing FF-MAS with 22R-HC at $0.70\,\mu\text{mol dm}^{-3}$ was significant at 0.05 probability level. Explain what this means.
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(d) (i) State whether or not the evidence in Table 2.1 supports the original hypothesis that FF-MAS activates the specific membrane receptor, LXR alpha. Explain your answer.
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(d) (ii) State the conclusions that can be drawn from the results in Table 2.1.
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568
508
533
