You will need to know:-

the principal changes which occur at adolescence both in boys and girls

the terms gamete (reproductive cell) and zygote (fertilized female cell which has not yet begun dividing).  The gametes each contain only half the genetic material needed to make a new life. so two are needed (one male and one female) to create a zygote.

the relative numbers and sizes of eggs and sperm and their roles

that fertilisation is the union of a sperm with an egg, bringing together through the genes some of the characteristics of both parents

the structure and functions of the human reproductive system and how sperm and eggs are brought together

the menstrual cycle in outline only  (hormonal control is not required)

how the fetus is protected and nourished in the uterus, and how its waste materials are eliminated.