Mitosis Part of eukaryotic cell division during which the cell nucleus divides.
Cytokinesis Division of the cytoplasm during cell division.
Chromatid One of two identical “sister” parts of a duplicated chromosome.
Centromere Area where the chromatids of a chromosome are attached.
Interphase Period of the cell cycle between cell divisions.
Cell Cycle Series of events that cells go through as they grow and divide.
Prophase 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 Fanlike microtubule structure that helps separate the chromosomes during mitosis.
Metaphase 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 Fourth and final phase of mitosis, during which the chromosomes begin to disperse into a tangle of dense material.
Key Concept What are the main events of the cell cycle? During the cell cycle, a cell grows, prepares for division, and divides to form two daughter cells, each of which then begins the cycle again.
Key Concept What are the four phases of mitosis? Biologists divide the events of mitosis into four phases: prophase, metaphase, anaphase, and telophase.