In this Unit students are introduced to the cell as the basic unit of life and the fact that a new life begins from a cell.In man, when a sperm fuses with an ovum it may develop into an embryo.

• 细胞与人类的繁殖生物的基本单位：细胞新生命的诞生：受精作用、植入、胚胎在母体内的成长青春期：性徵、男性和女性的生殖系统、生殖系统成熟的徵兆怀孕：怀孕的徵兆、怀孕期、为人父母的准备；