Chapter 12: The Cell Cycle and Chapter 13: Meiosis

61699697	mitosis	nuclear division that does not create genetic diversity
61699698	gametes	sex cells whose purpose is to fuse with one another (syngamy)
61699699	syngamy	the fusion of two gametes, which produces a zygote
61699700	zygote	one cell created by the fusion of two gametes
61699701	embryo	a multicellular zygote
61699702	binary fission	the way in which prokaryotes and bacteria divide when an exact copy of a cell is made, and then the copy and original split
61699703	somatic cells	non-sex cells
61699704	sister chromatids	copies of DNA before they become chromosomes; they are still bound at the centromere; they have the same alleles and the same genes
61699705	histones	protein groups that are present in DNA to help organize it
61699706	separate, repair, organize, make mRNA	roles of proteins in DNA
61699707	homologous chromosomes	pairs of chromosomes; each one in the pair has the same length, same shape, and same genes in same spot, but can have different alleles
61699708	alleles	different forms of the same gene
61699709	haploid cells	cells that have one type of chromosome (no homologous pairs)
61699710	diploid cells	cells that have two of each type of chromosome (homologous pairs); gives an insurance policy against mutations that can kill you
61699711	haploid cells	n
61699712	diploid cells	2n
61699713	prophase	chromatin fibers become tightly coiled, nucleoli disappear, each duplicated chromosome appears as two identical sister chromatids joined at their centromeres and along arms, mitotic spindle begins to form, centrosomes move away from each other
61699714	metaphase	centrosomes are at opposite poles of cell, chromosomes convene on the metaphase plate, for each chromosome kinetochores of sister chromatids are attached to kinetochore microtubules coming from opposite poles
61699715	anaphase	begins when cohesin proteins are cleaved, allowing two sister chromatids of each pair to part suddenly--each chromatid becomes a chromosome; daughter chromosomes move toward opposite ends of cell, cell elongates, two ends of cell are symmetric
61699716	telophase	two daughter nuclei form, nuclear envelopes arise from fragments of parent cell, nucleoli reappear, chromosomes decondense
61699717	cytokinesis	division of cytoplasm that finalizes the creation of daughter cells; animal cells have cleavage furrow, plant cells have cell plate
61699718	cell cycle	the life of a cell from the time it is formed from a dividing parent cell until its own division into two cells
61699719	mitosis	the division of the nucleus
61699720	meiosis	cell division which yields nonidentical daughter cells that have only one set of chromosomes; only occurs in gametes
61699721	mitotic phase	includes both mitosis and cytokinesis; shortest part of cell cycle
61699722	interphase	a long phase of the cell cycle that accounts for 90% of the cycle
61699723	G1 phase	"first gap" in which the cell grows; lasts 5-6 hours
61699724	S phase	"synthesis" in which the cell continues to grow and chromosomes are duplicated; lasts 10-12 hours
61699725	G2 phase	"second gap" in which the cell grows and prepares to divide; lasts 4-6 hours
61699726	M phase	the cell divides, the cycle repeats (lasts under an hour)
61699727	mitotic spindle	a structure that forms within a cell during prophase; consists of fibers made of microtubules and associated proteins; uses microtubules from the cytoskeleton, which partially disassembles before the mitotic spindle is formed; adding subunits of tubulin elongates spindle and taking them away shortens it
61699728	centrosome	a sub-cellular region containing material that functions throughout the cell cycle to organize the cell's microtubules
61699729	aster	the radial array of short microtubules that extends from the centrosome
61699730	kinetochore	a structure of proteins associated with specific sections of chromosomal DNA at the centromere; present in each of two sister chromatids of a replicated chromosome
61699731	metaphase plate	the imaginary plate that forms during metaphase at which the centromeres of duplicated chromosomes align
61699732	cleavage	the process by which cytokinesis occurs
61699733	cleavage furrow	the first sign of cytokinesis in animal cells, which is represented by a shallow groove in the cell surface near the old metaphase plate
61699734	cell plate	the sign of cytokinesis in plant cells in which vesicles derived from the Golgi move along microtubules to the center of the cell where they coalesce
61699735	origin of replication	a specific place on the bacterial chromosome at which cell division begins
61699736	checkpoint	a control point in the cell cycle where stop and go-ahead signals regulate the cycle; signals are transmitted via signal transduction
61699737	G0 phase	a nondividing, stalled state that ensues when no go-ahead signal is received by the cell at the G1 checkpoint
61699738	cyclin	a protein that has a cyclically fluctuating concentration in the cell to be active
61699739	MPF	the activated form of cyclin that triggers prophase of mitosis and phosphorylates other enzymes that catalyze individual steps of prophase
61699740	CDKs	enzymes in an inactive form that are present in consistent concentrations over the cell cycle; *most significant enzyme in regulating cell cycle
61699741	growth factors	molecules present in the cell cycle that act like hormones in that they cause a chemical change and send chemical signals; necessary for cell division
61699742	mutagens	factors that cause mutations
61699743	carcinogens	factors that cause cancer
61699744	anchorage dependence	the need for a cell to attach itself to something else when dividing; cancer cells lack this
61699745	spore	one haploid cell, does not fuse during syngamy, divides by mitosis
61699746	sporophyte	the multicellular diploid stage of a plant; makes spores
61699747	gametophyte	the multicellular haploid stage of a plant; makes gametes
61699748	alternation of generations	demonstrated by the plant life cycle because it alternates from sporophyte (diploid) to gametophyte (haploid)
61699749	synapsis	occurs when homologous chromosomes find one another to create a group of four strands of chromatin (known as a tetrad); occurs during prophase I
61699750	tetrad	a group of four strands of chromatin that is formed during synapsis in prophase I
61699751	crossing over	the exchange of exactly corresponding regions of two homologous chromosomes in a tetrad; causes genetic variation; occurs roughly 2-3 times per tetrad
61699752	gametogenesis	the creation of gametes
61699753	spermatogenesis	the creation of sperm
61699754	oogenesis	the creation of eggs
61699755	density-dependent inhibition	a phenomenon in which crowded cells stop dividing; cancer cells lack this
61699756	transformation	the sign of abnormal behavior in a normal cell that qualifies it as a cancer cell
61699757	benign tumor	a tumor that consists of cells that remain at the original site
61699758	malignant tumor	a tumor that consists of cells that become invasive enough to impair organ function
61699759	metastasis	occurs when tumor cells can enter blood vessels and travel to other parts of the body to grow
61699760	ectopic pregnancy	occurs when the embryo implants itself in the fallopian tube and begins to grow there; the baby will not survive, the mother can be endangered
61699761	1	number of divisions in mitosis
61699762	2	number of divisions in meiosis
61699763	2	number of daughter cells in mitosis
61699764	4	number of daughter cells in meiosis
62195361	nonvascular plants	plants known as bryophytes; classic example is moss
62195362	nonvascular plants	plants that typically form in large patches of green on the forest floor, dead logs, or bricks; do not contain xylem or phloem; usually are present only in sporophyte stage
62195363	gametangia	the structures in which gametes are made; only present in gametophytes
62195364	archegonia	the structures within gametangia that make eggs
62195365	artheridia	the structures within gametangia that make sperm
62195366	sporangia	the location on a plant at which spores are made; located in the capsule of the diploid sporophyte
62195367	vascular plants	plants the evolved second; contain xylem and phloem but lack seeds; classic example is a fern
62195368	fronds	fern leaves that grow from the base of the plant, originating in a curled state so that they unravel as they grow
62195369	fiddlehead	an immature frond
62195370	sori	black or brown structures on the underside of frond leaflets (known as sporangi) that are evidence for spore production
62195371	seed plants	plants that evolved third; called gymnosperms
62195372	seed plants	plants without fruits or flowers; produce naked seeds because they are not surrounded by fruit; examples include conifers, cycads, and Ginkgo trees
62195373	flowering plants	plants that have seeds, vascular tissues, flowers, and fruits; most successful group in kingdom plantae
62195374	flowering plants	plants known as angiosperms or anthophytes
62195375	stamen	the male structure on a flower that is composed of a stalk and a bulb
62195376	filament	the stalk of a stamen
62195377	anther	the bulb of a stamen that makes pollen
62195378	carpel	the female structure on a flower that is composed of the ovary, ovules, style, and stigma; sometimes called a pistil
62195379	style	the stalk that comes from the ovary
62195380	stigma	the top of the style on the carpel that receives the pollen
62410243	central cell	a cell that contains two haploid nuclei and is present within the ovule of a flowering plant
62410244	seven-cell female gametophyte	a structure contained inside each ovule that makes haploid eggs
62410245	double fertilization	one sperm fertilizes an egg and the other sperm fertilizes the central cell, which produces endosperm
62410246	tube cell	the cell from a male plant that grows down the style to the opening of the micropyle; grows a pollen tube