The MCAT is primarily a multiple-choice exam that tests knowledge of science as well as skills (such as problem solving and critical thinking) desirable for success in the medical profession. The test is made up of four sections: Verbal Reasoning, Physical Sciences, Biological Sciences, and Writing. The Writing Sample section requires the student to write essay responses to questions. The test is given twice a year at hundreds of test centers around the United States. The student should expect to spend all day at the testing center; a lunch break and other shorter breaks are included. Students must register for the test online.