| A | B |
|---|
| organism | A living thing |
| cell | The basic unit of structure and function in living things |
| unicellular | A type of organism that is made up of a single cell |
| multicellular | A type of organism that is made up of many cells |
| development | The process of change that occurs during an organism's life to produce a more complex organism |
| stimulus | A change in an organism's surroundings that causes the organism to react |
| response | An action or change in behavior that occurs as a result of a stimulus |
| reproduce | The production of offspring that are similar to the parents |
| spontaneous generation | The mistaken idea that living things arise from nonliving sources |
| controlled experiment | An experiment in which all of the variables except for one remain the same |
| manipulated variable | The one factor that a scientist changes to test a hypothesis during an experiment; also called the independent variable |
| autotrophs | An organism that makes its own food |
| heterotrophs | An organism that cannot make its own food |
| homeostasis | The process by which an organism's environment is kept stable in spite of changes in the external environment |
| compound microscopes | Two or more elements that are chemically combined |
| cell theory | A widely accepted explanation of the relationship between cells and living things |
| magnification | The ability to make things look larger than they are |
| convex lens | A curved lens in which the center is thicker than the edge |
| resolution | The ability to clearly distinguish the individual parts of a stimulus |
| organelle | A tiny cell structure that carries out a specific function within the cell |
| cell wall | A rigid layer of nonliving material that surrounds the cells of plants and some other organisms |
| cell membrane | The outside boundary of a cell; controls which substances can enter or leave the cell |
| chromatin | Material in cells that contains DNA and carries genetic information |
| cytoplasm | The region of a cell located inside the cell membrane (in prokaryotes) or between the cell membrane and nucleus ( in eukaryotes ); contains a gel-like material and organelles |
| mitochondria | Rod-shaped cell structures that produce most of the energy needed to carry out the cell's function |
| endoplasmic reticulum | A cell structure that forms a maze of passgeways in which proteins and other materials are carried from one part of the cell to another |
| ribosomes | A tiny structure in the cytoplasm of a cell where protiens are made |
| golgi bodies | A structure in a cell that receives proteins and other newly formed materials from the endoplasmic reticulum, packages them, and distributes them to other parts of the cell |
| chloroplasts | A structure in the cells of plants and some other organisms that captures energy from sunlight and uses it to produce food |
| vacuole | A water-filled sac inside a cell that acts as a storage area |
| lysosomes | A small round cell structure that contains chemicals that break down large food particles into smaller ones |
| prokaryotes | An organism whose cells lack a nucleus and some other cell structures |
| eukaryotes | An organism with cells that contain nuclei and other cell structures |
| fossil | The preserved remains or traces of an organism that lived in the past |
