BIO 110 Module 6 Lecture: Cell Replication

anaphase

stage of mitosis during which sister chromatids are separated from each other

binary fission

prokaryotic cell division process

cell cycle

ordered sequence of events that causes it to divide into two daughter cells

mitosis

ordered series of events involving cell growth and cell division that causes it to divide into 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

condensin

proteins that help sister chromatids coil during prophase

cytokinesis

division of the cytoplasm following mitosis that forms two daughter cells.

diploid

cell, nucleus, or organism containing two sets of chromosomes (2n)

G0 phase

distinct from the G1 phase of interphase; a cell in … is not preparing to divide

G1 phase

stage that focuses on cell growth and protein synthesis

G2 phase

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

complete set of 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

mitosis

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

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

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 gene that has the potential to cause cancer

origin

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

S phase

second, or synthesis, stage of interphase during which DNA replication occurs

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

homologous

one maternal and one parental chromosome pairing together in a cell

heterologous

pair of chromosomes that carry different genes

linker DNA

DNA between two neighboring nucleosomes that holds the cores together

contractile ring

generates the constricting force to divide one cell into two cells

external factors that initiate or inhibit the cell cycle

death of nearby cells, release of growth hormones, cell crowding

G1 checkpoint

assesses integrity of DNA and determines if the cell if ready to divide, also known as restriction point

G2 checkpoint

ensures DNA is replicated correctly and without damage before cell division

M checkpoint

ensures that chromosomes are attached to the spindle microtubules and are ready to divide

positive regulators

promote movement to the next step of the cell cycle

negative regulators

stop advancement of the cell cycle