| A | B |
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| cell | in biology, the smallest unit that can perform all life processes |
| cell membrane | a phospholipid layer that covers a cell's surface; acts as a barrier between the inside of a cell and the cell's environment |
| organelle | one of the small bodies in a cell's cytoplasm that are specialized to perform a specific function |
| nucleus | in a eukaryotic cell, a membrane-bound organelle that contains the cell's DNA and that has a role in processes such as growth, metabolism, and reproduction |
| prokaryote | an organism that consists of a single cell that does not have a nucleus |
| eukaryote | an organism made up of cells that have a nucleus enclosed by a membrane |
| cell wall | a rigid structure that surrounds the cell membrane and provides support to the cell |
| ribosome | cell organelle composed of RNA and protein; the site of protein synthesis |
| endoplasmic reticulum | a system of membrances that is found in a cell's cytoplasm and that assists in the production, processing, and transport of proteins and in the production of lipids |
| mitochondrion | in eukaryotic cells, the cell organelle that is surrounded by two membranes and that is the site of cellular respiration |
| Golgi complex | cell organelle that helps make and packages materials to be transported out of the cell |
| vesicle | a small cavity or sac that contains materials in a eukaryotic cell |
| lysosome | a cell organelle that contains digestive enzymes |
| tissue | a group of similar cells that perform a common function |
| organ | a collection of tissues that carry out a specialized function of the body |
| organ system | a group of organs that work together to perform body functions |
| organism | a living thing; anything that can carry out life processes independently |
| structure | the arrangement of parts in an organism |
| function | the special, normal, or proper activity of an organ or part |
