The knowledge points of biological reproduction and development in senior two include reproductive organs and reproductive processes. Men have testicles and women have ovaries. After fertilization, a fertilized egg is formed, which develops into an embryo in the uterus and then gives birth. Embryo development is influenced by heredity, environment, nutrition and endocrine. In addition, it also involves the characteristics of adolescent development, health care and sex education. This knowledge helps students to understand physical changes and keep healthy and safe.