The nervous system is the body's control and communication network. These elements connect the brain and spinal cord to muscles and glands. Your body is made up of billions of cells.
Cells are the basic unit of all living things.
Even single-celled organisms such as bacteria can perform the basic functions needed to sustain life. These basic functions include gathering energy from food, reproducing, and producing waste material. An outer wall called a membrane . A nucleus that contains essential chemicals. A body of clear fluid called the cytoplasm .