Some students carried out an investigation into the effect of light on the development of a type of leaf. Fig. 1.1 (opposite) shows six of these leaves that developed in sunlight and six that developed in shade. (a) Measure the maximum width of the leaves and record your measurements in Table 1.1. Leaf 1, ‘Leaves developed in sunlight’, indicates where measurements should be taken. Table 1.1 maximum width of leaf / $\text{mm}$ --- --- --- leaves developed in sunlight leaves…

Biology 5090/62 — May/June 2012

Cambridge O-Level · Alternative to Practical · worked solutions for every part, with the mark scheme

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marks

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Topics Experimental Contexts · Analysis, Conclusions and Evaluation · Microscopy and Biological Drawing · Observations and Measurements · Planning Experiments and Investigations · Use of Techniques, Apparatus and Materials

Q116MObservations and MeasurementsExperimental ContextsAnalysis, Conclusions and EvaluationPlanning Experiments and InvestigationsMicroscopy and Biological DrawingFree sample

Some students carried out an investigation into the effect of light on the development of a type of leaf.

Fig. 1.1 (opposite) shows six of these leaves that developed in sunlight and six that developed in shade.

Fig. 1.1

(a)

Measure the maximum width of the leaves and record your measurements in Table 1.1. Leaf 1, ‘Leaves developed in sunlight’, indicates where measurements should be taken.

Table 1.1

	maximum width of leaf / $\text{mm}$
	leaves developed in sunlight	leaves developed in shade
1
2
3
4
5
6
mean

(b)

(i)

Calculate the mean measurements and record them in the bottom row in Table 1.1.

(ii)

Using your measurements and Fig. 1.1 suggest how light has affected the development of these leaves.

______

(iii)

Suggest ways in which you could extend this part of the investigation.

______

(c)

Leaves were collected and sections produced.

Fig. 1.2 shows drawings of sections through two leaves, one developed in sunlight and one in shade. Both sections have been drawn to the same scale.

Fig. 1.2

(i)

Using Fig. 1.2, complete Table 1.2 by stating one observable difference between leaves developed in sunlight and shade for each of the features listed.

Table 1.2

feature	leaves in sunlight	leaves in shade
palisade cells
thickness of leaf
chloroplasts
air spaces

(ii)

Suggest how these differences enable the leaves to function in their environment.

______

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3 more questions

Q2Analysis, Conclusions and Evaluation · Observations and Measurements · Experimental Contexts6M
Q3Microscopy and Biological Drawing · Experimental Contexts · Use of Techniques, Apparatus and Materials · Analysis, Conclusions and Evaluation13M
Q4Microscopy and Biological Drawing · Experimental Contexts5M

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