@croydon - I think that really is the best way to increase your vocab. Not just read that book, but to read widely about biology in general.
New Scientist is a good read and there are hundreds of really interesting, down to earth science books available if you have a look at the library.
If you keep a biology dictionary handy and look words up whenever you don't understand them you will quickly build up your knowledge.
But if you just try to repeat a bunch of words by rote... well, I think you will learn them temporarily, but in the long run you might not remember them as well.