Science requirements should be completed (excluding English and mathematics) by the end of junior year or at the very latest by the beginning of senior year, unless you intend to delay admission to professional school.
Although there is a high degree of uniformity among the various health professions, some variation in these requirements does occur. More detailed information is available in the 2014-15 Freshman Sophomore Pre-Health Handbook (pdf). These variations are succinctly explained in the individual professions' pages (links at left). See the Pre-Health Advisor for more details. For other allied health professions, please see the Pre-Health Advisor.