This book, as well as the others in the Instant Notes series, is brilliant. It's perfect for revision and background reading because it has all you need in a consise, yet detailed layout which is easy to understand and learn.
It's the ideal book for undergraduate Biologists who are fed up of tralling through endless textbooks being unable to find details on a subject which isn't over the top with detail.
At a fraction of the cost of most textbooks, this is the ideal replacement if you don't intend to specialise in the subject.