Plants Definitions

lauramacv11's version from 2015-12-10 15:21

Section 1

Question Answer
Accessory fruit Fleshy fruit developing from a succulent receptacle rather than the pistil
Actinomorphic flowerRadially symmetrical flower.
Adventitious roots Roots developing in an unusual position, such as on the stem
Aggregate fruitCluster or small group of fleshy fruits originating from a number of separate pistils in a single flower, such as the drupelets making up a raspberry
AngiospermA plant that produces flowers and bears ovules in an ovary
Anther The expanded, apical, pollen bearing portion of the stamen.
AntheridiumThe male reproductive structure in moss and fern gametophytes
Apex The tip; the point farthest from the point of attachment
Apical meristemThe meristem at the tip of a root or shoot
Archegonium Female reproductive structure in moss and fern gametophytes
AuxinClass of plant hormones that control cell elongation, among other effects
Axillary budBud occurring in the axil of a leaf
AxilThe point of the upper angle formed between the axis of a stem and any part (usually a leaf) arising from it

Section 2

Question Answer
Bryophytesnonvascular land plants; the mosses hornworts and liverworts
BulbAn underground bud with thickened fleshy leaf scales, as in an onion
CalyxCollective term for all the sepals in a flower
CelluloseA carbohydrate; the chief component of the cell wall in plants
CorollaCollective name for all the petals of a flower
CotyledonA primary leaf of the embryo; a seed leaf
Determinate growthGrowth of limited duration, characteristic of floral meristems and leaves
DicotGroup of flowering plants characterized by having two seed leaves
DrupeA fleshy, indehiscent fruit with a stony endocarp surrounding a usually single seed, as in a peach or cherry.
Embryo A young sporophytic plant, before the start of a period of rapid growth (germination in seed plants).
Embryo sacThe female gametophyte of angiosperms, generally an eight-nucleate, seven-celled structure; the seven cells are the egg cell, two synergids and three antipodals (each with a single nucleus), and the central cell (with two nuclei)
EndocarpThe inner layer of the pericarp of a fruit.
EndospermA tissue, containing stored food, that develops from the union of a male nucleus and the polar nuclei of the central cell; it is digested by the growing sporophyte either before or after the maturation of the seed; found only in angiosperms
Epigynous flowerFlower with stamens, petals, and sepals attached to the top of the ovary, the ovary inferior to the other floral parts.

Section 3

Question Answer
Ferna seedless non-flowering vascular plant
FertilizationThe fusion of two gamete nuclei to form a diploid zygote
FilamentThe stalk of a stamen
FiberAn elongated support cell with secondary walls; found in vascular plants
FruitMature ovary
GametophyteGamete producing plant; generally haploid, and producing gametes by mitosis
GibberellinsClass of plant hormones, the best known effect of which is to increase the elongation of plant stems.
GymnospermA seed plant with seeds not enclosed in an ovary; the conifers are the most familiar gymnosperm group
HardwoodsAngiosperm trees; the wood produced by angiosperm trees
Hornwort Small group of bryophytes, most having only one large chloroplast per cell
HyphaeTubular filaments composing a fungal mycelium
Hypogenous flowerFlower with stamens, petals, and sepals attached below the ovary, the ovary superior to the other floral parts
Indeterminate growthUnrestricted or unlimited growth, as with a vegetative apical meristem that produces a number of lateral organs indefinitely
Inferior ovaryAn ovary that is attached beneath the point of attachment of the other floral whorls that therefore appear to arise from the top of the ovary
InflorescenceA flower cluster, with a definite arrangement of flowers.
IntegumentsThe coverings of the ovule which will become the seed coat
Internode The region of stem between two successive nodes

Section 4

Question Answer
Lateral meristemMeristem that gives rise to secondary tissue; the vascular cambium and cork cambium
Lichen Symbiotic relationship of fungus and alga.
LigninComplex molecule associated with cellulose in some secondary cell walls; serves to harden and strengthen the walls
LiverwortBryophyte group with leafy thalli
MegasporeA haploid spore that develops into a female gametophyte in heterosporous plants.
MeristemThe undifferentiated, perpetually young plant tissue from which new cells arise.
MesophyllThe parenchyma tissue of a leaf, located between the layers of epidermis; mesophyll cells generally contain chloroplasts.
MicropyleIn the ovules of seed plants, the opening in the integuments through which the pollen tube usually enters
MicrosporangiumA sporangium within which microspores are formed
Microspore In heterosporous plants, a spore that develops into a male gamete.
MicrosporocyteMicrospore mother cell; a cell in which meiosis wil occur, resulting in four microsopres.
MidribThe central rib or vein of a leaf or other organ.
Monocot Plants with a single seed leaf, or cotyledon.
MyceliumMass of hyphae; the thallus of a fungus
MycorrhizaeSymbiotic associations of fungi and roots or rootlike structures

Section 5

Question Answer
NodeThe position on a stem where leaves or branches originate.
OvaryThe enlarged basal portion of a carpel or of a pistil composed of fused carpels; a mature ovary is a fruit
OvuleA structure in seed plants containing the female gametophyte with egg cell, all being surrounded by the nucellus and one or two integuments; when mature, becomes a seed.
Palisade mesophyllParenchyma tissue on the upper side of the leaf, made up of tightly packed columnar cells, each bearing many chloroplasts.
ParenchymaTissue composed of living, thin-walled cells
ParthenocarpyDevelopment of a fruit without fertilization or seed production
PerianthThe calyx and corolla of a flower, collectively
PericarpThe wall of the fruit
Perigynous flowerwith stamens, petals, and sepals borne on a calyx tube (hypantheium) surrounding, but not actually attached to, the superior ovary.
PetalA member of the innermost whorl of the perianth of a flower, often showy
Petiole A leaf stalk.
PhloemThe food-conducting tissue of vascular plants
PhyllotaxisThe arrangement of plant parts (such as leaves) on a stem)
PistilThe female reproductive organ of a flower, typically consisting of a stigma, style, and ovary; may be composed of several carpels.
PollenThe mature microspores or developing male gametophytes of a seed plant, produced in the microsporangium.
Pollen generative cellCell of a male gametophyte that divides to produce sperm
Pollen vegetative cell Cell of microgametophyte that forms the pollen tube through which the generative cell travels.
PollinationIn angiosperms, transfer of pollen from an anther to a stigma. In gymnosperms, transfer of pollen from a pollen-producing cone directly to an ovule
Prop rootA root emerging from stem tissue that helps to support the plant.

Section 6

Question Answer
ReceptacleThe part of the axis of a flower stalk that bears the floral organs.
RhizomeA more or less horizontal underground stem
Root capA thimblelike mass of cells that covers and protects the growing tip of a root
SeedMatured ovule; it consists of an embryo generally in an arrested stage of development, usually stored food, and usually a protective covering.
Seed coatThe outer layer of the seeds, developed from the integuments of the ovule
SepalOutermost whorl of the perianth in angiosperms
SoftwoodsConiferous trees; the wood of coniferous trees.
Spongy mesophyll Mesophyll on the underside of a leaf, consisting of lobed cells with large intercellular spaces.
SporophyteThe (normally) diploid asexual phase of the life cycle producing haploid spores which give rise to the sexual gametophyte.
StamenThe microsporangium (anther) together with its stalk (filament)
StigmaPortion of angiosperm flower on which pollen is deposited.
StolonAn aerial stem that grows horizontally along the ground surface and may form adventitious roots, such as the runners of a strawberry plant.
StomataMinute openings bordered by guard cells in the epidermis of leaves and stems through which gases pass (water vapor, CO2 and O2)
Style The usually narrowed portion of the pistil connecting the stigma to the ovary
Superior ovaryAn ovary in which the floral structures (calyx, corolla, stamens) are inserted below it.

Section 7

Question Answer
TetradA group of four spores formed from a spore mother cell by meiosis (e.g. pollen tetrad)
TracheidsAn elongated, thick-walled water conducting and support cell of xylem. It has tapering ends and pitted walls without perforations; found in nearly all vascular plants.
TranspirationThe loss of water vapor by plant parts; most transpiration occurs through stomata
TuberAn enlarged, short, fleshy underground stem, such as that of the potato.
Turgor pressure The pressure within a cell resulting from the movement of water into the cell.
Vascular bundleA strand of tissue containing primary xylem and primary phloem and frequently enclosed by a bundle sheath of parenchyma or fibers
Vascular cambiumA cylindrical sheath of meristematic cells, the division of which produces secondary phloem (to the outside) and secondary xylem (to the inside).
Vascular plantsPlants that have xylem and phloem.
VeinA vascular bundle forming part of the framework of the conducting and supporting tissue of a leaf or other expanded organ
VenationArrangement of veins in the leaf blade
VesselA tubelike structure of the xylem composed of elongate cells (vessel elements) placed end to end and connected by perforations. Its function is to conduct water and minerals through the plant body . Found in nearly all angiosperms and a few other vascular plants.
Vivipary Sprouting on the parent plant, as the seeds of certain mangroves
WhorlA ring-like arrangement of similar parts arising from a common point or node
WoodSecondary xylem.
XylemA complex vascular tissue through which most of the water and minerals of a plant are conducted. Characterized by the presence of tracheids and/or vessels
Zygomorphic flowerA bilaterally symmetrical flower