The GRE (Graduate Record Examination) is the standard entrance exam for many graduate programs. It is a broad assessment of your critical thinking, analytical writing, verbal reasoning, and quantitative reasoning skills. There are also subject specific test for Biochemistry, Cell and Molecular Biology, Biology, Chemistry, Literature in English, Mathematics, Physics, and Psychology.
The Official GRE Test Site has all accurate and updated information regarding the test, and will answer any questions you may have about specific tests and scoring.
Note: Some business schools have transitioned from the GRE to the GMAT as the entrance exam of choice. Therefore, be sure to contact the school(s) to which you intend to apply to confirm the testing requirements.