SERIES EDITOR’S PREFACE
Teaching programmes in universities now are generally arranged in collections of discrete
units. These go under various names such as units, modules, or courses. They usually
stand alone as regards teaching and assessment but, as a set, comprise a programme of
study. Usually around half of the units taken by undergraduates are compulsory and
effectively define a ‘core’ curriculum for the final degree. The arrangement of teaching
in this way has the advantage of flexibility. The range of options over and above the core
curriculum allows the student to choose the best programme for her or his future.
The Lifelines series provides a selection of texts that can be used at the undergradu-
ate level for subjects optional to the main programme of study. Each volume aims to cover
the material at a depth suitable to a particular level or year of study, with an amount of
material appropriate to around one quarter of the undergraduate year. The concentra-
tion on life science subjects in the Lifelines series reflects the fact that it is here where
individual topics proliferate.
Suggestions for new subjects and comments on the present volumes in the series are
always welcomed and should be addressed to the series editor.
John Wrigglesworth
London, March 2000