Ch 5 Flashcards
Parenchyma
thin primary wall; alive at maturity; many functions; active metabolically; some involved in photosynthesis (chlorenchyma); some secrete nectar, fragrences and oils; some are transfer cells; some conduct nutrients over long distances (phloem)
Collenchyma
unevenly thickened primary wall; usually thickened in the corners; alive at maturity; plastic support: can be deformed by pressure or tension; can be stretched; in elongating shoot tips
Slerenchyma
primary wall and thickened secondary wall; walls are elastic: can be deformed and return to original shape; dead at maturity; elastic support and transport; two types conducting and mechanical
Nodes
where leaves are attached
internodes
regions between nodes
Leaf axil
stem area just above the point where a leaf attaches
Axillary bud
a minature shoot in the lead axil with a dormant apical meristem and several young leaves; either a vegetative bud (branch) or flower bud (flower or group of flowers)
Bud scales
small, corky, waxy, modified leaves that covers the bud
Terminal bud
a bud at the extreme tip of each stem
Phyllotaxy
arrangement of leaves on the stem
Alternate
one leaf present at each node
Opposite
two leaves per node
Whorled
three or more leaves per node
Distichous
leaves are arranged in only two rows; ie corn and irises
Decussate
leaves are arranged in four rows
Spiral
each leaf is slightly to the side of the ones immediately above and below it and the leaves form a spiral up the steam (most common arrangement)
Stolons
an aerial stem with elongate internodes; it establishes plantlets periodically when it contacts soil; ie strawberry
Bulbs
a short, subterranean (concealed), vertical stem that has fleshy scalelike leaves; ie onion
Corms
subterranean, vertical stem that is thick and fleshy and has only thin papery leaves; ie gladiolus (flower)
Rhizomes
fleshy, horizontal, subterranean stem involved in allowing the plant to migrate laterally; ie bamboo and iris
Tubers
short, fleshy, horizontal stem, involved in storing nutrients but not in migrating laterally; ie potato
Epidermis
the outermost layer of the plant primary body, covering leaves, flower parts, young stems and roots; made up of a single layer of living parenchyma cells
Cuticle
layer of cutin (fatty acid substance making water impermeable) on epidermal cells; restricts entry of carbon dioxide and water
Wax
extremely hydrophobic; contributes to water containing capacity of epidermis
Stoma
can also mean “stomatal pore” (see def) and can also mean “stomatal complex” guard cells plus stomatal pore
Guard Cells
pair of epidermal cells capable of adjusting their size and shape, causing the stomatal pore to open when they swell and close when they shrink
Stomatal Pore
intracellular space between two guard cells; CO2 is absorbed through the pore and water is lost
Trichomes
plant hair
Cortex
below the epidermis; between the epidermis and phloem in stems and roots; composed of photosynthetic parenchyma and sometimes collenchyma
Vascular Xylem
the water and mineral conducting portion of vascular tissues, containing either tracheids or vessel elements or both
Tracheids
a xylem conducting cell; type of sclerenchyma; tend to be long and tapered with no perforations
Vessel Element
type of sclerenchyma; xylem conducting cell that has one or two perforations (complete hole in the primary wall that permits water to flow easily from one vessel to another)
Vascular Phloem
distributes sugars and minerals
Sieve Cells
phloem conducting cells in angiosperms; long and tapered
Albuminous cells
nurse cell connected to and controlling a enucleate sieve cell in the gymnosperm phloem
Sieve tube members
in the phloem of the angiosperms, a column of sieve tube members interconnected by large sieve areas and sieve pores
Companion cells
nurse cell that is connected to and a sister cell to an enucleate sieve tube member
Vascular Bundle
column of vascular tissue, typically both xylem and phloem together, but in leaves sometimes consisting of only one or the other
Pith
region of parenchyma located in the center of most shoots and some roots, surrounded by vascular bundles
Apical Meristem
a group of cells specialized for the production of new cells located at the farthest point of the tissue or organ produced
Subapical Meristem
the region of a shoot or root just proximal to the apical meristem
Protoderm
any immature epidermal cell
Provascular
cells in the primary plant body that later differentiate into xylem, phloem or vascular cambium
Ground Meristem
any expanse of meristematic tissue that produces somewhat uniform mature tissue
Primary Tissues
the tissues derived more or less directly from an apical meristem or leaf primordium; the tissues of the primary plant body
Primary Growth
production of new cells by shoot and root apical meristems and leaf primordia
Determinate Growth
growth that stops at a genetically predetermined size; typically of leaves and flowers but not of whole shoots and roots
Indeterminate Growth
growth not limited by a plant’s own genetic development program; most trees have this
Determinate Organogenesis
number of organs is predetermined; humans
Indeterminate Organogenesis
number of organs is not written in the organism’s genetic code; plants
