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chemical level

the lowest level of organization that is composed of atoms and molecules


anything that has mass and occupies space


are the smallest particles that are considered matter


two or more atoms joined together


the smallest living thing in an organism


the organs of cells


a bunch of cells grouped together so they can work together to accomplish a purpose (e.g. bone tissue structurally supports the body)


tissue that covers or lines stuff


tissue that has tons of extracellular matrix

extracellular matrix

stuff that surrounds the cells in a tissue (and is in fact produced by them)


a combination of two or more types of tissue that perform a complicated function (e.g. the stomach has epithelial and muscle tissue and it digests food)

carbon dioxide

what we breathe out

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