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an ordered sequence of events in the life of a cell, from its origin in the division of a parent cell until its own division into 2; euakryotic cycle - interphase (including G1, S and G2 subphases) and M phase (including mitosis and cytokinesis)
the genetic material of an organism or a virus; the complete complement of an organism's or virus's genes along with its noncoding nucleic acid sequences.
a cellular structure carrying genetic material, found in the nucleus of eukaryotic cells; each consists of one very long DNA molecule and associated proteins. (bacterial chromosome usually consists of single circular DNA molecule and associated proteins. Found in nucleoid region, which is not membrane bound)
the complex of DNA and proteins that makes up eukaryotic chromosomes. When the cell is not dividing, they exist in dispersed form - mass of very long, thin fibers that are not visible with a light microscope.
a haploid reprodice cell, such as an egg or sperm; unite during sexual reproduction to produce a haploid zygote.
two copies of a duplicated chromosome attached to each other by proteins at the centromere and, sometimes, along the arms. While joined, 2 make up one chromosome. Eventually they are separated during mitosis or meiosis II
in a duplicated chromosome, the region on each sister chromatid where they are most closely attached to each other by proteins that bind to specific DNA sequences; close attachment causes a constriction in the condensed chromosome (an uncondensed, unduplicated chromosome has a single one, identified by its DNA sequence)
a process of nuclear division in eukaryotic cells conventionally divided into 5 stages: prophase, prometaphase, metaphase, anaphase, and telophase; conserves chromosome number by allocating replicated chromosomes equally to each of the daughter nuclei,
the division of the cytoplasm to form 2 separate daughter cells immediately after mitosis, meiosis I or meiosis II
the period in the cell cycle when the cell is not dividing. Cellular metabolic activity is high, chromosomes and organelles are duplicated, and cell size may increase. Accounts for about 90% of the cell cycle.
the first gap, or growth phase, of the cell cycle, consisting of the portion of interphase before DNA synthesis begins
the synthesis part of the cell cycle; the portion of interphase during which the DNA is replicated
the second gap, or growth phase, of the cell cylcle, consisting of the portion of interphase after DNA synthesis occurs
the first stage of mitosis, in which the chromatin condenses into discrete chromosomes visible with a light microscope, the mitotic spindle begins to form, and the nucleolus disappears but the nucleus remains intact
the second stage of mitosis, in which the nuclear envelope fragments and the spindle microtubules attach to the kinetochores of the chromosomes
the third stage of mitosis, in which the spindle is complete and the chromosomes, attached to the microtubules at their kinetochores, are all aligned at the metaphase plate
the fourth stage of mitosis, in which the chromatids of each chromosome have separated and the daughter chromosomes are moving to the poles of the cell
the fifth and final stage of mitosis, in which daughter nuclei are forming and cytokinesis has typically begun
a structure present in the cytoplasm of animal cells, that functions as a microtubule-organizing center and is important during cell division; has 2 centrioles
a radial array of short microtubules that extends from each centrosome toward the plasma membrane in an animal cell undergoing mitosis
a structure of proteins attached to the centromere that links each sister chromatid to the mitotic spindle
an imaginary structure located at a plane midway between the two poles of a cell in metaphase on which the centromeres of all the duplicated chromosomes are located
the process of cytokinesis in animal cells characterized by pinching of the plasma membrane; the succession of rapid cell divisions without significant growth during early embryonic development that converts the zygote to a ball of cells
the first sign of cleavage in an animal cell; a shallow groove around the cell in the cell surface near the old metaphase plate
a membrane-bounded, flattened sac lopcated at the midline of a dividing plant cell, inside which the new cell wall forms during cytokinesis
a method of asexual reproduction by "division in half." IN prokaryotes - does not involve mitosis, single-celled eukaryotes that undergo binary fission, mitosis is part of the process
origin of replication
site where the replication of a DNA molecule begins, consisting of a specific sequence of nucleotides
a cellular protein that occurs in a cyclically fluctuating concentration and that plays an important role in regulating the cell cycle
cyclin-dependent kinase (Cdk)
a protein kinase that is active only when attached to a particular cyclin
maturation-promoting factor (or M-phase-promoting factor); a protein complex required for a cell to progress from late interphase to mitosis. The active form consists of cyclin and a protein kinase
a protein that must be present in the extracellular environment (culture medium or animal body) for the growth and the normal development of certain types of cells. A local regulator that acts on nearby cell to stimulate cell proliferation and differentiation
the phenomenon observed in normal animal cells that causes them to stop dividing when they come into contact with one another
the requirement that a cell must be attached to a substratum in order to initiate cell division
the conversion of a normal animal cell to a cancerous cell. A change in a genotype and phenotype due to the assimilation of external DNA by a cell. When the external DNA is from a member of a different species, transformation results in horizontal gene transfer.
a mass of abnormal cells with specific genetic and cellular changes such that the cells are not capable or surviving at a new site and generally remain at the site of the tumor's origin
a cancerous tumor containing cells that have significant genetic and cellular changes and are capable of invading and surviving in new sites. Can impair functions of one or more organs
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