Some Vocabulary to Know

Molecule: A group of atoms bonded together, eg: H20 (water) is 2 hydrogen atoms and 1 oxygen atom. Other examples: protein, DNA, fat, sugar. 
Cell: The smallest living unit. Made up of lots of molecules. Cells need water, food, and a way to divide and reproduce themselves. Different types of cells are the building blocks of the organs in the body. 
DNA: A spiral-shaped protein found in almost all cells in all living creatures. It contains the instructions for the cells to make proteins, which pretty much do almost everything in the body. 
Hormone: A molecule that is sent through the bloodstream to carry a message from one organ to another. Eg: estrogen carries information from the ovaries to the brain. Another example: the brain sends out FSH to the ovaries. 
Uterus: The organ in the female pelvis from where the menstrual blood comes out, or, if pregnant, the fetus develops inside. 
Ovaries: The organs in your body connected to your uterus that store and release eggs. 
Hypothalamus & Pituitary: The parts of your brain that send out sex hormones through the blood to communicate with the ovaries.