Provides an understanding of the biology of human health and disease as it affects public health. Normal biochemistry, physiology and immunology of healthy humans. Exploration of mechanisms responsible for genetic, nutritional, infectious, toxic and chronic diseases and their effects on human populations. Factors affecting human health and disease during stages of human development including infancy, youth, reproduction, pregnancy and aging. Examine the basis for current health promotion, disease prevention and control strategies. Note: Credit may not be obtained for both PHS 506 and SPH 506.