Botany Chp 35-39 Flashcards

331327696	axillary bud	a structure that has the potential to form a lateral shoot (branch) ; usually dormant
331327697	terminal bud	makes up the shoot apex along with developing leaves and a compact series of nodes and internodes
331327698	apical dominance	phenomenon in which the proximity of the terminal buds is partly responsible for inhibiting the growth of axillary buds
331327699	epidermis	nonwoody plants; the single layer of tightly packed cells
331327700	periderm	protective layer in woody plants that replace the epidermis in older regions of stems and roots
331327701	xylem	vascular tissue that conveys water and dissolved minerals upward from roots into the shoots
331327702	phloem	vascular tissue that transports organic nutrients such as sugars from where they are made to where they are needed
331327703	stele	the collective term for the vascular tissue of a root or stem
331327704	vascular cylinder	(in angiosperms) solid cylinder, the stele of the root
331327705	vascular bundles	stele of stems and leaves divided into strands consisting of xylem and phloem
331327706	pith	ground tissue internal to the vascular tissue
331327707	cortex	ground tissue external to the vascular tissue
331327708	parenchyma	cells that are relatively thin and flexible; has a large central vacuole; least specialized structurally; perform most of the metabolic functions of the plant, synthesizes and stores various organic products; retain ability to divide and differentiate into other types of plants
331327709	collenchyma	cells that support young parts of the plant ; lack secondary walls; allow flexible support without restraining growth
331327710	sclerenchyma	cells dead at functional maturity ; rigid walls that provide support and strengthening; have two types of cells (sclereids and fibers)
331327711	sclereids	type of sclerenchyma ; shorter than fibers and irregular in shape
331327712	fibers	type of sclerenchyma; usually arranged in threads; long, slender, and tapered
331327713	tracheids	water-conducting cell of xylem; long, thin cells with tapered ends; water moves from cell to cell mainly through the pits (does not have to cross secondary walls)
331327714	vessel elements	water- conducting cell of xylem; wider, shorter , thinner walled; end walls of vessel elements have perforations that enable water to flow freely through the vessels
331327715	sieve tube members	chains of sieve cells that transport nutrients; lack nucleus, ribosomes and a distinct vacuole
331327716	sieve plates	end walls between sieve tube members; have pores that facilitate the flow of fluid from cell to cell along the sieve tube
331327717	companion cell	nucleus and ribosomes serve not only the cell itself but the adjacent sieve tube member; helps load sugars into the sieve tube members
331327718	initials	cells that remain as sources of new cells
331327719	derivatives	new cells displaced from the meristem
331327720	primary plant body	parts of the troot and shoot systems produced by apical meristems during primary growth
331327721	endodermis	innermost layer of the cortex; a cylinder one cell thick that forms the boundary with the vascular cylinder
331327722	pericycle	outermost cell layer in the vascular cylinder where lateral roots arise from
331327723	leaf primordia	finger-like projections along the flanks of the apical meristem
331327724	palisade mesophyll	parenchyma; consists of one or more layers of elongated cells on the upper part of the leaf
331327725	spongy mesophyll	parenchyma; cells are more loosely arranged which allows CO2 and O2 to pass through easier
331327726	leaf traces	connections from vascular bundles in the stem; pass through petioles and into leaves
331327727	bundle sheath	protective consisting of one or more layers of parenchymal cells that encloses the vein
331327728	secondary plant body	consists of the tissues produced by the vascular cambium and cork cambium
331327729	vascular cambium	adds secondary xylem and secondary phloem
331327730	cork cambium	produces a tough, thick covering consisting mainly of cork cells
331327731	fusiform initials	produce elongated cells such as tracheids, vessel elements and fibers of the xylem
331327732	ray initials	produce vascular rays (radial files consisting mainly of parenchymal cells)
331327733	heartwood	older layers of secondary xylem that no longer transport water and minerals; closer to the center of a stem or root
331327734	sapwood	outer layers that still transport xylem sap
331327735	lenticels	raised areas dotting the periderm that enable living cells within a woody stem or root to exchange gases with the outside air
331327736	bark	all tissues external to the vascular cambium
331327737	membrane potential	voltage; separation of opposite charges across a membrane; charge separation is a form of potential energy that can be harnessed to perform cellular work
331327738	cotransport	mechanism in which a transport protein couples the downhill passage of one solute to the uphill passage to another
331327739	chemiosmosis	transmembrane protein gradient ; links energy releasing processes to energy-consuming processes
331327740	water potential	combined effects of solute concentration and physical pressure; moves from regions of higher to regions of lower
331327741	solute potential	also called osmotic potential because solutes affect the direction of osmosis
331327742	vacuolar membrane	also called a tonoplast; regulates molecular traffic between the cytosol and the vacuolar contents
331327743	symplast	cytoplasmic continuum
331327744	apoplast	continuum of cell walls plus the extracellular spaces
331327745	bulk flow	movement of a fluid driven by pressure
331327746	Casaparian strip	belt made of suberin (waxy material impervious to water and dissolved minerals)
331327747	endodermis	innermost layer of cells in the root cortex; surrounds the vascular cylinder and functions as a last checkpoint for the selective passage of minerals from the cortex into the vascular tissue
331327748	transpiration	the loss of water vapor from leaves and other aerial parts of the plant
331327749	guttation	the exudation of water droplets when root pressure sometimes causes more water to enter the leaves than is transpired
331327750	root pressure	an upward push of xylem sap
331327751	sugar source	plant organ that is a net producer of sugar
331327752	transfer cells	modified companion cells that enhance transfer of solutes between apoplast and symplast
331327753	microspores	haploids formed when microsporocytes undergo meiosis; eventually give rise to haploid male gametophyte
331327754	megaspores	haploid produced when megasporocyte undergoes meiosis
331327755	double fertilization	ensures that the endosperm will develop only in ovules where the egg has been fertilized (prevents from squandering nutrients)
331327756	endosperm	food-storing tissue of the seed from the triploid nucleus
331327757	hypocotyl	embryonic axis
331327758	epicotyl	portion of the embryonic axis where the cotyledons are attached
331327759	coleoptile	sheath that covers the young shoot
331327760	coleorhiza	sheath that covers the young root
331327761	scutellum	specialized type of cotyledon that has a large surface area which absorbs nutrients during germination
331327762	vegetative reproduction	asexual reproduction; mature fragments from the plant
331327763	fragmentation	separation of a parent plant into parts that develop into whole parts that develop into whole plants
331327764	apomixis	asexual production of seeds; no joining of sperm and egg; diploid cell in ovule gives rise to the embryo
331327765	callus	mass of dividing, undifferentiated cells as a result of cutting
331327766	etiolation	morphological adaptation for growing in the dark
331327767	second messengers	small internally produced chemicals that transfer and amplify the signal from the receptor to other proteins that cause the response
331327768	auxin	found in the embryo of seeds, meristems of apical buds, and young leaves; stimulates stem elongation, root growth, cell differentiation, branching; regulates development of fruit; enhances apical dominance; retards leaf abscission
331327769	Cytokinins	synthesized in roots and transported to other organs; affect root growth and differentiation; stimulate cell division and growth; stimulate germination; delay senescence
331327770	Gibberellins	meristems of apical buds and roots, young leaves, embryo; promote seed and bud germination, stem elongation, and leaf growth; stimulate flowering and development of fruit; affect root growth and differentiation
331327771	brassinosteroids	seeds, fruit shoots, leaves, and floral buds; inhibit root growth; retard leaf abscission; promotes xylem differentiation
331327772	abscisic acid	leaves, stems , roots , green fruit; inhibits growth, closes stomata, promotes seed dormancy
331327773	ethylene	tissues of ripening fruit, nodes of stems, aging leaves and flowers; promotes fruit ripening, opposes some auxin effects; promotes or inhibits growth and development of roots, leaves and flowers