| A | B |
|---|
| tissue | a group of cells that work together to perform a specific job |
| organ | two or more tissues working together to perform a specific function |
| organ system | a group of organs that works together to perform body functions |
| unicellular | made of a single cell |
| multicellular | made of many cells |
| population | a group of individuals of the same species that live together in the same area at the same time |
| community | all of the populations of different species that live and interact in an area |
| ecosystem | a community of organisms and their nonliving environment |
| cell | a membrane-covered structure that contains all of the materials necessary for life |
| cell membrane | a phospholipid layer that covers a cell's surface and acts as a barrier between the inside of acell and the cell's environment |
| organelles | a structure within a cell, sometimes surrounded by a membrane |
| cytoplasm | cellular fluid surrounding a cell's organelles |
| nucleus | the membrane-covered organelle found in eukaryotic cells; contains the cell's DNA and serves as a control center for the cell |
| prokaryotic | cell that does not have a nucleus or any other membrane-covered organelles; also called a bacterium |
| eukaryotic | cell that contains a central nucleus and a complicated internal structure |
| bacteria | extremely small, single-celled organisms without a nucleus; prokaryotic cells |
| phospholipid | a type of lipid molecule that forms much of a cell's membrane |
| cell wall | a structure that surrounds the cell membrane of some cells and provides strength and support to the cell membrane |
| ribosome | a small organelle in cells where proteins are made from amino acids |
| endoplasmic reticulum | a membrane-covered cell organelle that produces lipids, breaks down drugs and other substances, and packages proteins for delivery out of the cell |
| mitochondria | cell organelles surrounded by two membranes that break down food molecules to make ATP |
| chloroplast | an organelle found in plant and algae cells where photosynthesis occurs |
| Golgi complex | the cell organelle that modifies, packages, and transports materials out of the cell |
| vesicle | a membrane-covered compartment in a eukaryotic cell that forms when part of the cell membrane surrounds an object and pinches off |
| vacuole | a large membrane-covered structure found in plant cells that serves as a storage container for water and other liquids |
| lysosome | a special vesicle in a cell that digests food particles, wastes, old cell parts, and foreign invaders |
