anaphase
stage of mitosis during which sister chromatids are separated from each other
binary fission
prokaryotic cell division process
cell cycle
ordered series of events involving cell growth and cell division that produces two new daughter cells
cell cycle checkpoint
mechanism that monitors the preparedness of a eukaryotic cell to advance through the various cell cycle stages
cell plate
structure formed during plant cell cytokinesis by Golgi vesicles, forming a temporary structure (phragmoplast) and fusing at the metaphase plate; ultimately leads to the formation of cell walls that separate the two daughter cells
centriole
rod-like structure constructed of microtubules at the center of each animal cell centrosome
centromere
region at which sister chromatids are bound together; a constricted area in condensed chromosomes
chromatid
single DNA molecule of two strands of duplicated DNA and associated proteins held together at the centromere
cleavage furrow
constriction formed by an actin ring during cytokinesis in animal cells that leads to cytoplasmic division
condensin
proteins that help sister chromatids coil during prophase
cyclin
one of a group of proteins that act in conjunction with cyclin-dependent kinases to help regulate the cell cycle by phosphorylating key proteins; the concentrations of cyclins fluctuate throughout the cell cycle
cyclin-dependent kinase
one of a group of protein kinases that helps to regulate the cell cycle when bound to cyclin; it functions to phosphorylate other proteins that are either activated or inactivated by phosphorylation
cytokinesis
division of the cytoplasm following mitosis that forms two daughter cells.
diploid
cell, nucleus, or organism containing two sets of chromosomes (2n)
FtsZ
tubulin-like protein component of the prokaryotic cytoskeleton that is important in prokaryotic cytokinesis (name origin: Filamenting temperature-sensitive mutant Z)
Gphase
distinct from the G1 phase of interphase; a cell in G0 is not preparing to divide
G1 phase
(also, first gap) first phase of interphase centered on cell growth during mitosis
G2 phase
(also, second gap) third phase of interphase during which the cell undergoes final preparations for mitosis
gamete
haploid reproductive cell or sex cell (sperm, pollen grain, or egg)
gene
physical and functional unit of heredity, a sequence of DNA that codes for a protein.
genome
total genetic information of a cell or organism
haploid
cell, nucleus, or organism containing one set of chromosomes (n)
histone
one of several similar, highly conserved, low molecular weight, basic proteins found in the chromatin of all eukaryotic cells; associates with DNA to form nucleosomes
homologous chromosomes
chromosomes of the same morphology with genes in the same location; diploid organisms have pairs of homologous chromosomes (homologs), with each homolog derived from a different parent
interphase
period of the cell cycle leading up to mitosis; includes G1, S, and G2 phases (the interim period between two consecutive cell divisions
karyokinesis
mitotic nuclear division
kinetochore
protein structure associated with the centromere of each sister chromatid that attracts and binds spindle microtubules during prometaphase
locus
position of a gene on a chromosome
metaphase
stage of mitosis during which chromosomes are aligned at the metaphase plate
metaphase plate
equatorial plane midway between the two poles of a cell where the chromosomes align during metaphase
mitosis
(also, karyokinesis) period of the cell cycle during which the duplicated chromosomes are separated into identical nuclei; includes prophase, prometaphase, metaphase, anaphase, and telophase
mitotic phase
period of the cell cycle during which duplicated chromosomes are distributed into two nuclei and cytoplasmic contents are divided; includes karyokinesis (mitosis) and cytokinesis
mitotic spindle
apparatus composed of microtubules that orchestrates the movement of chromosomes during mitosis
nucleosome
subunit of chromatin composed of a short length of DNA wrapped around a core of histone proteins
oncogene
mutated version of a normal gene involved in the positive regulation of the cell cycle
origin
(also, ORI) region of the prokaryotic chromosome where replication begins (origin of replication)
p21
cell cycle regulatory protein that inhibits the cell cycle; its levels are controlled by p53
p53
cell cycle regulatory protein that regulates cell growth and monitors DNA damage; it halts the progression of the cell cycle in cases of DNA damage and may induce apoptosis
prometaphase
stage of mitosis during which the nuclear membrane breaks down and mitotic spindle fibers attach to kinetochores
prophase
stage of mitosis during which chromosomes condense and the mitotic spindle begins to form
proto-oncogene
normal gene that when mutated becomes an oncogene
quiescent
refers to a cell that is performing normal cell functions and has not initiated preparations for cell division
retinoblastoma protein (Rb)
regulatory molecule that exhibits negative effects on the cell cycle by interacting with a transcription factor (E2F)
S phase
second, or synthesis, stage of interphase during which DNA replication occurs
septum
structure formed in a bacterial cell as a precursor to the separation of the cell into two daughter cells
telophase
stage of mitosis during which chromosomes arrive at opposite poles, decondense, and are surrounded by a new nuclear envelope
tumor suppressor gene
segment of DNA that codes for regulator proteins that prevent the cell from undergoing uncontrolled division