Name ___________________________________________________________ Date _____________
Absorption Worksheet 

1.     (a)	Define the term absorption.
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(1)
(b)	Figure 1 below shows a cross-section through the small intestine and Figure 2 an enlarged longitudinal section through a single villus.

Figure 1	Figure 2
	[Source: adapted from M Roberts et al.,	[Source: adapted from Taylor et al.,
Advanced Biology, Nelson, 2000, page 185]	Biological Science 1
	Cambridge University Press, 1997, page 244]
	Using these diagrams, outline three ways in which the structure of the small intestine is related to its function of absorbing food.
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(3)
(Total 4 marks)

2.	Which of the following structures help the absorption of food by the small intestine?
I.	Capillary networks
II.	Villi
III.	Microvilli
IV.	Membrane proteins
A.	I and II only
B.	II and III only
C.	II, III and IV only
D.	I, II, III and IV
(Total 1 mark)
3.	Explain the mechanisms used by the ileum to absorb food.
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(Total 6 marks)

4.	The diagram below shows a transverse section of the ileum.

[Source: P H Raven and G B Johnson, Biology, (2002), 6th edition, McGraw-Hill, page 1024]
(a)	(i)	State the name and function of the structures labelled 1 and 2.
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2:	............................................................................................................................
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(2)
(ii)	Distinguish between the muscles labelled 3 and 4.
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(1)
(Total 3 marks)

5.	Male Lepidoptera (butterflies and moths) commonly drink from pools of water or from moist soil. This behaviour, called puddling, was investigated in an undisturbed area where male tiger swallowtails, Papilio glaucus, had been seen puddling.
	Four successive sets of experiments were performed under similar conditions of temperature and humidity. In each set, equal samples of sand were spread out evenly on trays and then treated differently. Except for one dry sample (in the first set), all others were saturated with a different liquid. Results of the observations are given in the table below.

	[Source: adapted from K Arms et al., “Sodium: Stimulus for Puddling Behaviour by Tiger Swallowtail Butterflies, Papilio glaucus” (1974) Science, 185: 5 (5 July–27 Sept) #4148, pp. 372–374. Reprinted with permission from AAAS]
(a)	Identify the dissolved element always present in the three samples with most puddling time.
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(1)
(b)	Discuss the relationship between sampling visits (V) and puddling time (T) in experiments 1, 2 and 3.
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(2)
(c)	Analyse the results for experiment 4.
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(2)
	Study of the male moth Gluphisia septentrionis revealed that their puddling behaviour can last for hours. Though drinking results in the uptake of hundreds of gut-loads of fluid, this fluid becomes rapidly expelled from the digestive system through frequent anal ejections. In this experiment, the ion concentration change was calculated by subtracting ions ejected from ions taken in. The following data was collected from males drinking laboratory solutions and from natural puddles.

	[Source: adapted from SR Smedley and T Eisner “Sodium Uptake by Puddling in a Moth” (1995) Science, 270 (15 Dec) #5243, pp. 1816–1818. Reprinted with permission from AAAS]
(d)	(i)	Identify which ion the moths are retaining in their body from the laboratory solutions.
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(1)
(ii)	Compare the gain and loss of ions in the male moths which have drunk from laboratory solutions with the changes in those that have drunk from natural puddles.
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(3)
	The diagram below shows the digestive system anatomy of the male and female moth.
		
	[Source: adapted from SR Smedley and T Eisner “Sodium Uptake by Puddling in a Moth” (1995) Science, 270 (15 Dec) #5243, pp. 1816–1818. Reprinted with permission from AAAS]
(e)	Using the diagram above, evaluate the hypothesis that male moths are better adapted than female moths to benefit from puddling behaviour.
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(2)
(f)	Suggest one reason for puddling behaviour in male Lepidoptera.
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(1)
(Total 12 marks)