Chapter 8 Key Terms Flashcards
Beginning when sister chromatids separate from each other and ending when a complete set of daughter chromosomes has arrived at each of the two poles of the cell
Anaphase
A chromosome not directly involved in determining the sex of an organism; in mammals, for example, any chromosome other than X or Y
Autosome
An abnormal mass of cells that remains at its original site in the body
Benign Tumor
An ordered sequence of events (including interphase and mitotic phase) that extends from the time a eukaryotic cell is first formed from a dividing parent cell until it’s own division in two cells
Cell Cycle
The reproduction of a cell
Cell Division
The region of a chromosome where two sister chromatids are joined and where spindle microtubules attach during mitosis and meiosis. The centromere divides at the onset of anaphase during mitosis and anaphase II of meiosis.
Centromere
The process of cytokinesis in animal cells, characterized by pinching of the plasma membrane.
Cleavage
The exchange of segments between chromatids of homologous chromosomes during prophase I of meiosis.
Crossing Over
The division of the cytoplasm to form two separate daughter cells. Cytokinesis usually occurs during telophase of mitosis, and the two processes (mitosis and cytokinesis) make up the mitotic (M) phase of the cell cycle.
Cytokinesis
Containing two sets of chromosomes (pairs of homologous chromosomes) in each cell, one set inherited from each parent; referring to a 2n cell.
Diploid
The union of a haploid sperm cell with a haploid egg cell, producing a zygote.
Fertilization
A sex cell; a haploid egg or sperm. The union of two gametes of opposite sex (fertilization) produces a zygote.
Gamete
Containing a single set of chromosomes; referring to an n cell.
Haploid
The two chromosomes that make up a matched pair in a diploid cell. Homologous chromosomes are of the same length, centromere position, and staining pattern and possess genes for the same characteristics at corresponding loci. One homologous chromosome is inherited from the organism’s father, the other from the mother.
Homologous Chromosomes
The phase in the eukaryotic cell cycle when the cell is not actually dividing. During interphase, cellular metabolic activity is high, chromosomes and organelles are duplicated, and cell size may increase. Interphase accounts for 90% of the cell cycle. See also mitosis.
Interphase
A display of micrographs of the metaphase chromosomes of a cell, arranged by size and centromere position.
Karyotype
An abnormal tissue mass that spreads into neighboring tissue and to other parts of the body; a cancerous tumor.
Malignant Tumor
In a sexually reproducing organism, the process of cell division that produces haploid gametes from diploid cells within the reproductive organs.
Meiosis
The second stage of mitosis. During metaphase, the centromeres of all the cell’s duplicated chromosomes are lined up along the center line of the cell.
Metaphase
The division of a single nucleus into two genetically identical daughter nuclei. Mitosis and cytokinesis make up the mitotic (M) phase of the cell cycle.
Mitosis
The phase of the cell cycle when mitosis divides the nucleus and distributes its chromosomes to the daughter nuclei and cytokinesis divides the cytoplasm, producing two daughter cells.
Mitotic Phase
A spindle-shaped structure formed of microtubules and associated proteins that is involved in the movement of chromosomes during mitosis and meiosis. (A spindle is shaped roughly like a football.)
Mitotic Spindle
An accident of meiosis or mitosis in which a pair of homologous chromosomes or a pair of sister chromatids fails to separate at anaphase.
Nondisjunction
The bead-like unit of DNA packing in a eukaryotic cell; consists of DNA wound around a protein core made up of eight histone molecules.
Nucleosome
The first stage of mitosis. During prophase, duplicated chromosomes condense to form structures visible with a light microscope, and the mitotic spindle forms and begins moving the chromosomes toward the center of the cell.
Prophase
One of the two identical parts of a duplicated chromosome. While joined, two sister chromatids make up one chromosome; chromatids are eventually separated during mitosis or meiosis II.
Sister Chromatid
The fourth and final stage of mitosis, during which daughter nuclei form at the two poles of a cell. Telophase usually occurs together with cytokinesis.
Telophase
The fertilized egg, which is diploid, that results from the union of haploid gametes (sperm and egg) during fertilization.
Zygote
