|Insulin and glucagon are ____ that regulate blood glucose.
|Blood travels from your heart to your legs through ____.
|Human cells organize into ____ and then into organs.
|The brain, heart, stomach, and lungs are examples of ____.
|The various pigments that give skin and hair color are ____.
|The trachea divides into two main ____ that lead to the lungs.
|Proteins are polymers (chains) of ____.
|Blood travels from your legs to your heart through ____.