| A | B |
| cell division | the process by which the cell divides into two new daughter cells |
| chromatid | one of two identical "sister" parts of a duplicated chromosome |
| centromere | the area in which the chromatids of a chromosome are attached |
| interphase | the period of the cell cycle between cell divisions |
| cell cycle | the series of events that cells go through as they grow and divide |
| mitosis | part of eukaryotic cell division during which the cell nucleaus divides |
| prophase | the first and longest phase of mitosis, during which the chromosomes become visible and the centrioles separate and take up positions on the opposite sides of the nucleus |
| centriole | one of two tiny structures located in the cytoplasm of animal cells near the nuclear envelope |
| spindle | a fanlike microtubule structure that helps separate the chromosomes during mitosis |
| metaphase | the second phase of mitosis, during which the chromosomes line up across the center of the cell |
| anaphase | the third phase of mitosis, during which the chromosome pairs separate and move toward opposite poles |
| telophase | the forth and final phase of mitosis, during which the chromosomes begin to disperse into a tangle of dense material |
| cytokinesis | the division of the cytoplasm during cell division |
| cyclin | one of a family of closely related proteins that regulate the cell cycle in eukaryotic cells |
| cancer | a disorder in which some of the body's own cells lose the ability to control growth |