With my science study guide questions, 1. explain a placental mammal. 2. describe the female reproductive system in a human. 3. describe the male reproductive system in a human. 4. explain how a zygote develops and how a developing embryo is protected in a human.

1. Placental mammals are those mammals who pregnancy forms in the womb of the mother and forming a placenta between the embryo and the lining of the uterus. This is unlike other categories called marsupials and monotremes that raise their offspring on a pouch and lay eggs respectively.

2. The human's female reproductive duct is composed of the ovaries that release eggs regularly and fallopian tubes that connect the ovaries and the uterus. These eggs travel through the fallopian tube and get to the uterus. The uterus then descended and narrows down into the vagina.

3. The male reproductive system is composed of the testes that produce sperm (they are formed in the epididymis). The sperm travels through the epididymis and through the duct of the penis. The male reproductive system is mostly found ‘outside’ of the body, unlike the female’s.  

4. The zygote is formed when a sperm and an egg meet and fuse. This process is called fertilization. The sperm and egg are haploid and fuse to form a diploid zygote. The zygote begins to divide to develops into an embryo.