1.	(a)	Define the term homologous anatomical structures.
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(1)
 
(b)	Outline how membranes may have originated in the first cells.
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(2)
 
(c)	Discuss how variations in a specific protein can be used as an evolutionary clock.
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(3)
(Total 6 marks)

2.	(a)	(groups of organisms) with structural similarities that may have a
common ancestor	1
 
(b)	phospholipids self assemble into double layered structures;
they form into spheres capturing fluids;
	fluids contain molecules that can replicate / catalyse within their
boundaries;	2 max

(c)	mutations cause changes in the protein structure;
mutations have a fixed frequency of occurrence;
protein structure from common ancestor changes over time;
	the greater the difference between proteins, the more mutations have
occurred;
species more closely related have less differences in their protein structure;	3 max
[6]