Sites for practice GRE
Here are the practice GRE subject
tests. They have introductory material, the test, AND answer keys with them.
Note though, they are .pdf files, and about 60 pages
long,
so only print if you have the time to
wait AND the paper in your printer!
Biology Test: http://ftp.ets.org/pub/gre/Biology.pdf
Biochemistry, Cell, and Molecular
Biology Test:
http://ftp.ets.org/pub/gre/BioChem.pdf