Cell Growth and Division

Vocabulary


Cell Division

The process by which a cell divides to form two daughter cells. Upon completion of the process, each daughter cell contains the same genetic material as the original cell and roughly half of its cytoplasm.







Chromatid


Either of the two daughter strands of a replicated chromosome that are joined by a single centromere and separate during cell division to become individual chromosomes.














Centromere




A specialized structure on the chromosome, appearing during cell division as the constricted central region where the two chromatids are held together and form an X shape.














Interphase

The stage in the development of a cell following mitosis or meiosis, during which the nucleus is not dividing. In cells that will undergo further division, the DNA in the nucleus is duplicated in preparation for the next division.









Cell Cycle

The cycle of growth and asexual reproduction of a cell, consisting of interphase followed in actively dividing cells by prophase, metaphase, anaphase, and telophase.












Mitosis

The usual method of cell division, characterized typically by the resolving of the chromatin of the nucleus into a threadlike form, which condenses into chromosomes, each of which separates longitudinally into two parts, one part of each chromosome being retained in each of two new cells resulting from the original cell.












Prophase

The first stage of mitosis, during which the chromosomes condense and become visible, the nuclear membrane breaks down, and the spindle apparatus forms at opposite poles of the cell.







Centriole

A small, cylindrical cell organelle, seen near the nucleus in the cytoplasm of most eukaryotic cells, that divides in perpendicular fashion during mitosis, the new pair of centrioles moving ahead of the spindle to opposite poles of the cell as the cell divides: identical in internal structure to a basal body.








Spindle

A spindle-shaped structure, composed of microtubules, that forms near the cell nucleus during mitosis or meiosis and, as it divides, draws the chromosomes to opposite poles of the cell.







Metaphase

The stage of mitosis and meiosis, following prophase and preceding anaphase, during which the chromosomes are aligned along the metaphase plate.







Anaphase
The stage of mitosis and meiosis in which the chromosomes move to opposite ends of the nuclear spindle.








Telophase

The final stage of meiosis or mitosis, in which the separated chromosomes reach the opposite poles of the dividing cell and the nuclei of the daughter cells form around the two sets of chromosomes.





Cytokinesis

The division of the cell cytoplasm that usually follows mitotic or meiotic division of the nucleus.






Cyclin

A class of proteins that fluctuate in concentration at specific points during the cell cycle and that regulate the cycle by binding to a kinase.

Cancer

A malignant and invasive growth or tumor, esp. one originating in epithelium, tending to recur after excision and to metastasize to other sites.