100 Key Terms
- 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 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
- cell-cycle checkpoint
- mechanism that monitors the preparedness of a eukaryotic cell to advance through the various cell-cycle stages
- 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 (Cdk)
- 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)
- G0 phase
- 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