240-75 Ch 12 Terms Fa 09

240-75 Ch 12 Terms Fa 09 - BIO 240-75 Fall 2009 Vocabulary,...

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BIO 240-75 Fall 2009 Vocabulary, Concepts and Terms for Chapter 12 The Cell Cycle Cell division-the reproduction of cells; the continuity of life is based on cell division. Zygote-the diploid product of the union of haploid gametes during fertilization; a fertilized egg. Daughter cell-product of cell division of one cell results in the formation of two daugter cells. Genome- a cell's endowement of DNA, its genetic information. Chromosomes-a structure carrying genetic material, found in the nucleus of eukaryotic cells. Each chromosome consists of one very long DNA molecule and associated proteins. Somatic cells-all body cells except sex cells (not sperm or egg cell) Gametes-sperm and egg cells Chromatin-a complex of DNA and associated protein molecules. Sister chromatids-Each duplicated chromosome has two sister chromatids. The two chromatids, each containing an identical DNA molecule, are initially attached all along their lengths by adhesive protein copmlexes called cohesins. Centromere-a specialized region where the two chromatids are most closely attached. Mitosis-the division of the nucleus. Cytokinesis-the division of the cytoplasm; the division of the cytoplasm is usually wll underway by late telophase, so the two daughter cells appear shortly after the end of mitosis. In animal cells, cytokinesis involves the formation of a cleavage furrow, which pinches the cell in two. Meiosis-division of sex cells; yields nonidentical daughter cells that have only one set of chromosomes, thus half as many chromosomes as the parent cell. This only occurs in the gonads (ovaries or testes). Mitotic (M) phase-includes both mitosis and cytokinesis and is usually the shortest part of the cell cycle. Mitotic cell division alternates with a much longer state called
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interphase. Interpase -often accounds from about 90% of the cycle. It is during interphase that the cell grows and copies its chromosomes in preparation for cell division. It is divided into G1 phase, S phase, and G2 phase. G 1 phase-"first gap" the cell grows by producing proteins and cytoplasmic organelles S phase-"synthesis" the cell grows by producing proteins and cytoplasmic organelles, and chromosomes are duplicated. G 2 phase-"second gap" the cell grows by producing proteins and cytoplasmic organelles. G 0 phase-most cells of the human body are in this phase; a nondividing state occupied by cells that have left the cell cycle. Prophase-the chromatin fibers because more tightly coiled, condensing into discrete chromosomes observable with a light microscopes; The nucleoli disappear; Each duplicated chromosomes appears as two identical sister chromatids joined together at their centromeres and all along their arms by cohesins. The mitotic spindle begins to form, it is composed of the centrosomes and the microtubules that extend from them. The radial arrays of shorter microtubules that extend from the centrosomes are called asters.
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This note was uploaded on 02/17/2010 for the course BIO 240 taught by Professor Hoffman during the Fall '06 term at University of Louisville.

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240-75 Ch 12 Terms Fa 09 - BIO 240-75 Fall 2009 Vocabulary,...

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