Ch. 12 Vocab Flashcards
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 two
cell cycle
the complex of DNA and proteins that makes up a eukaryotic chromosome
chromatin
the specialized region of the chromosome where two sister chromatids are most closely attached
centromere
cellular structures carrying genetic material, found in the nucleus of eukaryotic cells; consists of one very long DNA molecule and associated proteins
chromosomes
the division of the cytoplasm to form two separate daughter cells immediately after mitosis, meiosis I, or meiosis II
cytokinesis
structure present in the cytoplasm of animal cells, important during cell division; functions as a microtubule-organizing center
centrosome
the first sign of cleavage in an animal cell; a shallow groove in the cell surface near the old metaphase plate
cleavage furrow
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
cleavage
a double membrane across the midline of a dividing plant cell, between which the new cell forms during cytokinesis
cell plate
a cyclically operating set of molecules in the eukaryotic cell that both triggers and coordinates key events in the cell cycle
cell cycle control system
a control point in the cell cycle where stop and go-ahead signals can regulate the cycle
checkpoint
a cellular protein that occurs in a cyclically fluctuating concentration and that plays an important role in regulating the cell cycle
cyclin
a protein kinase that is active only when attached to a particular cyclin
cyclin-dependent kinase (Cdk)
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
anaphase
the requirement that a cell must be attached to a substratum in order to divide
anchorage dependence
a method of asexual reproduction by “division of half”
binary fission
a mass of abnormal cells that remains at the site of its origin
benign tumor
the phenomenon observed in normal animal cells that causes them to stop dividing when they come into contact with one another
density-dependent inhibition
a radial array of short microtubules that extends from each centrosome toward the plasma membrane in an animal cell undergoing mitosis
aster
the genetic material of an organism or virus; the complete complement of an organism’s or virus’s genes along with its no coding nucleic acid sequences
genome
haploid reproductive cells, such as eggs or sperm
gametes
the first gap, or growth phase, of the cell cycle, consisting of the portion of interphase before DNA synthesis begins
G1 phase
the second gap, or growth phase, of the cell cycle, consisting of the portion of interphase after DNA synthesis occurs
G2 phase
a no dividing state occupied by cells that have left the cell cycle
G0 phase
a protein that must be present in the extra cellular environment for the growth and normal development of certain types of cells; a local regulator that acts on nearby cells to stimulate cell proliferation and differentiation
growth factor
the period in the cell cycle when the cell is not dividing
interphase
a structure of proteins attached to the centromere that links each sister chromatid to the mitotic spindle
kinetochore
a process of nuclear division in eukaryotic cells conventionally divided into five stages: prophase, prometaphase, metaphase, anaphase, telophase
mitosis
the phase of the cell cycle that includes mitosis and cytokinesis
mitotic (M) phase
a modified type of cell division in sexually reproducing organisms consisting of two rounds of cell division but only one round of DNA replication
meiosis
the third stage of mitosis, in which the spindle is complete and the chromosomes, attached to microtubules at their kinetochores, are all aligned at the metaphase plate
metaphase
an imaginary plane midway between the two poles of a cell in metaphase on which the centromeres of all the duplicated chromosomes are located
metaphase plate
an assemblage of microtubules and associated proteins that is involved in the movements of chromosomes during mitosis
mitotic spindle
a cancerous tumor that is invasive enough to impair the functions of one or more organs
malignant tumor
the spread of cancer cells to locations distant from their original site
metastasis
the second stage of mitosis, in which discrete chromosomes consisting of identical sister chromatids appear, the nuclear envelope fragments, and the spindle microtubules attach to the kinetochores of the chromosomes
prometaphase
the first stage of mitosis, in which the chromatin condenses, the mitotic spindle begins to form, and the nucleolus disappears, but the nucleus remains intact
prophase
any cell in a multicellular organism except a sperm or egg
somatic cells
either of two copies of duplicated chromosomes attached to each other by proteins at the centromere and, sometimes, along the arms
sister chromatids
the synthesis phase of the cell cycle; the portion of interphase during which DNA is replicated
S phase
the fifth and final stage of mitosis, in which daughter nuclei are forming and cytokinesis has typically begun
telophase
the conversion of a normal animal cell to a cancerous cell; a change in genotype and phenotype due to the assimilation of external DNA by a cell
transformation
short stretches of DNA having a specific sequence of nucleotides
origin of replication
the reproduction of cells
cell division
