| A | B |
|---|
| plasticity | an organism's ability to alter or "mold" itself in response to local environmental conditions |
| morphology | external form |
| tissue | group of cells with a common function, structure, or both |
| organ | consists of several types of tissues that together carry out particular functions |
| root system | reproductive flower, terminal bud, node, internode, vegetative shoot, leaf{blade, petiole}, Axillary bud, stem |
| shoot system | taproot, lateral roots |
| root | an organ that anchors a vascular plant, absorbs minerals and water, and often stores organic nutrients |
| taproot system | one main vertical root that forms and embryonic root |
| lateral roots | form off of the taproot |
| fibrous root system | mat of generally thin roots spreading out below the soil surface with no root standing out as the main one |
| adventitious | term describing any plant part that grows in an unusual location |
| root hair | an extention of a root epidermal cell |
| stem | organ consisting of an alternating system of nodes and internodes |
| nodes | the points at which leaves are attached |
| internodes | segments between nodes |
| axillary bud | a structure that has the potential to form a lateral shoot (aka branch) |
| terminal bud | compact series of nodes and internodes |
| apical dominance | phenomenon where the proximity of the terminal bud is partly responsible for the inhibiting growth of axillary buds |
| leaf | the main photosynthetic organ of most vascular plants. consists of a flatened blade and stalk |
| petiole | joins the leaf to a node of the system |
| types leaves | simple, compound, doubly compounded |
| modified leaves | tendrils, spines, storage, bracts, reproductive |
| tissue system | consists of one or more tissues organized into a functional unit connecting the organs of the plant |
| sermal tissue system | the outer protective covering |
| epidermis | single layer of tightly packed cells |
| periderm | protective tissues in woody plants that replaces the epidermis in older regions of stems and roots |
| cuticle | a waxy coating in the epidermis of leaves and most stems that helps prevent water loss |
| vascular tissue system | carries out long-distance transportation of materials between roots and shoots |
| xylem | conveys water and dissolved minerals upward from roots into shoots |
| phloem | transports organic nutrients such as sugars from where they are made to where they are needed |
| stele | collectievly refers to the vascular tissue of a root or stem |
| vascular cylinder | the stele of the root for angiosperms |
| vascular bundles | the stele of stems and leaves consisting of bundles of xylem and phloem |
| ground tissue system | tissues that is neither dermal nor vascular |
| pith | ground tissue that is internal to the vascular tissue |
| cortex | ground tissue that is external to the vascular tissue |
| protoplast | the cell contents within the cell wall |
| parenchyma cells | Primary cell walls thin and flexible; no secondary walls; large central vacuole; most metabolic functions of plant (chloroplasts) |
| collenchyma cells | Unevenly thick primary cell walls used for plant support (no secondary cell walls; no ligin) |
| sclerenchyma cells | type of sclerenchyma cells; support element strengthened by secondary cell walls lignin (may be dead; xylem cell); fibers and sclereids for support |
| sclereids | short and irregularly shaped; thick lignified cell walls |
| fibers | type of sclerenchyma cell; arranged in threads, long, slender, tapered |
| tracheids | found in xylem; long, thin, moves water from cell to cell; lignin |
| vessel elements | found in xylem, wide, short |
| sieve-tube members | found in phloem; few organels, walls have a sieve plate to help transportation |
| companion cell | connected to the sieve cell through mutiple pores; shares organels with the sieve cell |
| interminate growth | growth that occurs throughout the plant's life |
| determinate growth | cease growth after a certain size |
| annuals | complete their life cycle in a single year or less |
| biennials | live two years often including an intervening cold period between vegetative growth and flowering |
| perennials | live many years |
| meristems | perpetually embryonic tissues |
| apical meristems | located at the tips of roots and in buds of shoots, that provides additional cells that enable the plant to grow in lenght |
| primary growth | allows roots to extend throughout the soil and shoots to increase exposure to light and CO2 |
| herbaceous | nonwoody |
| secondary growth | growth in thickness |
| lateral meristems | the vascular cambium and cork cambium, which extend along the length of roots and stems |
| vascular cambium | adds layers of vascular tissue called secondary xylem (wood) and secondary phloem |
| cork cambium | replaces rhe epidermis with peridem which is thicker and thougher |
| initials | cells that remain as sources of new cells |
| derivatives | new cells displaced from the meristem that continue to divide until the cells they produce become specialized |
| primary plant body | parts of the root and shoot systems produced by apical meristems |
| root cap | protects the delicate apical meristem as the root pushes throught he abrasive soil during primary growth |
| zone of cell division | includes the root apical meristem and its derivatives |
| zone of elongation | roots cells elongate, sometimes to more than ten times their origional length |
| zone of maturation | cells complete their differentiation and become functionally mature |
| endodermis | the innermost layer of the cortex; a cylinder one cell thick that forms the boundary with the vascular cylinder |
| pericycle | the outermost cell layer in the vascular cylinder |
| leaf primordia | finger-like projections along the flanks of the apical meristem |
| stomata | allow CO2 exchange between the surrounding air and the photosynthetic cells inside the leaf |
| guard cells | regulate the opening and closing of the stomata |
| mesophyll | region between the upper and lower epidermis; consists mainly of parenchyma cells specialied for photosynthesis |
| palisade mesophyll | aka palisade parenchyma; consists of one or more layers of elongated cells on the upperside of the leaf |
| spongy mesophyll | aka spongy parenchyma; loosely aranged with a labryinth of air spaces through which CO2 and O2 circulate around the cells and up to the palisade region |
| leaf traces | connections from vascular bundles in the stemm |
| bundle sheath | protective cylinder around leaf traces consistinf of one or more layers of cells |
| passive transport | diffusion across a membrane |
| active transport | pumping of solutes across membranes against their electrochemical gradients (voltage and concentration gradient) |
| transport proteins | allow solutes to pass through the lipid bilayer of the membrane |
| proton pump | uses energy from ATP to pump H+ out of the cell |
| membrane potential | separation of opposite charges across a membrane |
| osmosis | the pasive transport of water across a membrane |
| water potential | the combined effects of solute concentration and physical pressure; determines the direction of movement of water; (psi) |
| solute pressure | porportional to the number of disolved solute molecules; always - |
| osmotic potential | same as solute potential |
| pressure potential | the physical pressure on a solution; can be + or - |
| turgor pressure | produced when the cell contents press the plasma membrane against the cell wall |
| flaccid | limp...like an old dude's penis |
| turgid | firm |
| aquaporions | transport proteins that transports water across vacuolar and plasma membranes |
| vacuolar membrane (or tonoplast) | regulates molecular traffic between the cytosol and the vacuolar membrane by chemiosmosis |
| symplast | cytoplasmic continuum of cell walls created by plasmodesmata connecting the cytosolic compartments of neighboring cells |
| apoplast | the continuum of cell walls plus the extracellular spaces |
| bulk flow | the movement of a fluid driven by pressure |
| mycorrhizae | symbiotic structures consisting of plant roots united with fungal hyphae |
| casparian strip | the radial walls of each endodermal cell; a belt made of xuberin, a waxy material impervious to water and dissolved minerals |
| transpiration | the loss of water vapor from leaves and other aerial parts of the plant |
| root pressure | an upward push of xylem sap |
| guttation | the exudation of water droplets that occurs when root pressure causes more water to enter the teh leaf than transpired |
| translocation | transport of organic nutrients in the plant |
| sugar source | a plant organ that is a net producer of sugar by photosynthesis or by breakdown of starch |
| sugar sink | an organ that is a net consumer or storer of sugar |
