Define the following terms- fertilization, puberty, implantation.

Fertilization is the process of combining the male gamete, or sperm, with the female gamete, or ovum. The product of fertilization is a cell called a zygote.

Puberty is the process of physical changes through which a child's body matures into an adult body capable of sexual reproduction. It is initiated by hormonal signals from the brain to the gonads: the ovaries in a girl, the testes in a boy.

Implantation is the attachment of the fertilized egg or blastocyst to the wall of the uterus at the start of pregnancy.