Exam 2 Flashcards
Sources and Sinks
Sources - Areas where certain molecules are FORCED INTO phloem by pumps
Sinks- areas where pumps of phloem EXTRACT molecules
Sieve Elements/members
Describes both types of conducting cells in phloem.
The two sieve elements are sieve cells and sieve tube members.
Sieve Cell
The conducting cells of the phloem of nonangiosperms.
Don’t have sieve plates like sieve tubes do, and all sieve areas are small and uniformly spread on all walls.
Sieve Pores
The actual small hole in the primary wall of a sieve area, through which hte cytoplasm of one sieve element is in contact with the cytoplasm of the next.
Sieve Areas
Modified primary pit fields in the wals of sieve elements.
Mediate transfer of nutrients from one sieve element to the next.
the plasmodesmata have been modified into sieve pores.
Sieve Plates
The end wall of a sieve tube member.
Simple Sieve Plates
sieve plate that has only a single sieve area
Compound Sieve Plate
A sieve plate that has more than one sieve area
Sieve Tube
A long, multicellular structure composed of many sieve tube members interconnected by their sieve plates.
Companion Cells
A cytoplasmic cell in the phloem of angiosperms. The have extensive cytoplasmic connections to the enucleate sieve tube members and are thought both to control their metabolism and to participate in the loading and unloading of nutrients.
Albuminous Cells
Same as companion cells, but these are found in nonangiosperms
Intermediary Cells
A type of parenchyma cell in the phloem of many angiosperms. Intermediary cells are responsible for the loading and unloading of nutrients into the adjacent sieve elements.
Refractive Spherules
A small round body that occurs in the sieve elements of many cryptogams
Nacreous Layer
A layer of opalescent wall material in sieve elements
Callose
A polymer of glucose with Beta (1-3) glycosidic bonds that is present in sieve elements; when the element is damaged, the callose precipitates and contributes to sealing the wound.
Connecting Strand
The strand of cytoplasm that runs through a sieve pore, connecting the protoplasm of one sieve elements with that of the adjacent sieve element
Mictoplasm
Watery cytoplasm that results when the vacuolar membrane breaks down during sieve element development and the cytoplasm mixes with the contents of the vacuole.
P-Type Plastids
A special type of plastid that occurs in sieve tube members; these plastids contain protein.
S-Type Plastids
A special type of plastid that occurs in sieve tube members; these plastids contain starch.
P-Protein
The protein filaments that occur in sieve elements, formerly called slime.
P-Protein Plug or slime plug
When the element is damaged and surging occurs, the P-protein forms a plug over the sieve area formerly called a sieve plug
Wound Callose
Sieve elements contain large amounts of callose which is pressure sensitive; When the element is damaged and surging begins, the callose precipitates and contributes to the plugging action
Def: Callose penetrates many areas and actually fills the sieve pores in response to injury.
Definitive Callose
When a sieve elements has completed its functioning, the cell collapses and the callose precipitates naturally and seals the sieve area completely
Nectary
A gland or trichome that secretes nectar (sugar water)
Nectar
sugary solution
Nectaries are subdivided into what two types?
Floral Nectaries- A nectary located on any part of the flower and Extrafloral nectaries - A nectary located anywhere on the plant except the flower
Hydathodes
A secretory structure usually consisting of epithem and a sheath. Secrete almost pure water and may be a means by which minerals are transported to young tissues more rapidly than would be possible by transpiration alone.
Salt Glands
An external secretory structure which secretes salt.
Osmophores
A gland that secretes fragrances of a flower
Adhesive Cells
Any cell that secretes a sticky substance that permits holdfasts to adhere to a surface
Resin Ducts
A long canal containing the sticky resin or “pitch” of gymnosperms
Mucilages
secretions that contain carbohydrates; they are slimy and have high water content
Oils
deposited into large cavities
Gums
located inside of the wood of certain species; result from modification of cell walls
Myrosin Cells
Contain the enzyme myrosinase in their central vacuoles;
Lactifers
secretes latex
Latex
“milk” of mlikweeds; creamy, white, thick substance
Gases fill what?
intercellular spaces
Eccrine Secretion
mechanism whereby the secretory product is transported out of the cytoplasm as individual molecules
Granulocrine Secretion
Secretory product is first accumulated inside of vesicles, through the action of the ER, the dictyosomes, or both.
Coated Vesicles
A small vesicle composed of plasmalemma and coated with clathrin
Clathrin
A type of coating surrounding a vesicle
Merocrine Secretion
Both eccrine and granulocrine methods of secretion are a subtype of this secretion; cells remain alive during secretion
Holocrine Secretion
product is secreted by the complete breakdown and disintegration of the cell
Excretions (classify basad on purpose of product)
materials that would be considered waste products
Secretions
Those that still have a function (such as nectars)
Recretions
Those that are passed through the plant without participating in metabolism
Endogenous Secretion
secretion that accumulated inside the plant body
Exogenous Secretion
secretion that accumulated outside the plant body
Cavity (chamber)
any isodiametric space, either secretor or not
Duct (canal)
any rather long tubular cavity either secretory or not
Recruitment
parenchyma cells in the vicinity of htte growing duct are converted into secretory cells
Schizogenously
Space forms by tearing of cells from each other
Lysigenously
Space forms by actual breakdown of cells; space formed by lysis
Schizolysigenously
Formation of an intercellular space or any other separation of tissues by a process involving both the tearing of cells away from each other and also the actual breakdown of the cells.
Lysis
The breakdown of an organelle or cell
Epithelium
The cellular lining of any secretory canal or chamber.
Casparian Strips
A layer or set of layers of suberin and sometimes also lignin in the radial walls of endodermal cells.
Articulated Laticifers
Laticifers made up of many cells
Nonarticulated Laticifers
Laticifers that consist of a single cell
Guttation
The secretion of water by hydathodes (a secretory strx consisting of an epithem and sheath)
Epithem
The loose, parenchyma cells at the end of one or several small veins in a leaf
Sheath
Layer of tight fitting cells surrounding the parenchyma
Water Pores
A modified stoma located over a hydathode.
Non-anastomosing
Any single laticifer never merges with another laticifer
Articulated Anastomosing Laticifers
One laticifer can fuse with others forming a 3D network
Lutoids
Rubber in form of latex present as globules
Bulbous Pockets
Regions in walls where latex ducts undergo modifications and begin swelling at certain sites.
Collecting Cells
A cell that is part of a secretory structure and is involved in transferring salt in salt glands from surrounding cells into the secretory structure.
Stalk Cell
Acts as an apoplastic barrier so salt can’t get back into plant once secreted
Secretory Cells
Carries salt in many small vesicles near plasmalemma to surface of gland.
Epifoliar
Refers to organisms living on the surface of the substrateLichens and algae grow in the tropics on the leaves of trees and vines; intercept light and interfere with photosynthesis
Fenestrae
Depressions/Widow-like pits in thickened epidermal walls
Ectodesmata
A channel in the outer wall of epidermal cells; resembles plasmodesmata.
Teichodes
A channel in the outer wall of epidermal cells (ectodesmata) and resemble a plasmodesmata but this term is only used when the channel is believed to be fundamentally different from plasmodesmata
Cutin
Primary component of cuticle; polymers of fatty acids
Cuticular Layer
Outer portion of the outer wall of the epidermis that is filled with cutin
Cuticle and Cuticle Proper
Refers NONspecifically to the layers of cutin and the cutin filled walls of epidermis
Proper- used to distinguish what layers
Cuticularization
Deposition of cutin on the exterior surface of the outer wall of an epidermal cell, forming a cuticle
Pectin Layer
Separates cuticle from cellulose wall
Epicuticular Wax
Wax on the surface of the cuticle
Intracuticular Wax
Wax in the form of particles within the cutin matrix.
Stomatal Pores
Intercellular space between a pair of guard cells; gas exchange
Guard Cells
Pair of crescent shape epidermal cells that surround the stomatal pore. The swelling or shrinking or them opens or closes the stoma.
Stoma
Designates the pore and guard cells of a stomatal complex.
Ventral Wall
The wall adjacent to the pore; thicker than dorsal wall
Dorsal Wall
Opposite wall, or back wall
Stomatal Complex
Guard cells + adjacent epidermal cells located around a pore.
Subsidiary Cells
Cells adjacent to stomatal complex that are distinct in size, shape, or cell contents.
Stomatal Cavity
A depression in the surface of a leaf, containing one or several stomata.
Ledges
ridges of the cuticle-covered wall material on the guard cell wall facing the stoma; if these ledges protrude toward the pore, then, as a stoma closes, the ledges of one guard cell contact the corresponding ledges of the other guard cell, forming a tight seal.
Anomocytic type (Type of Stomatal Complex)
epidermises in which there are no obvious subsidiary cells
Paraclytic type (Type of Stomatal Complex)
each guard cell is accompanied by one or more subsidiary cells that are aligned parallel with it
Diacytic type (Type of Stomatal Complex)
Two large subsidiary cells that completely surround the guard cells and are aligned perpendicular to them
Actinocytic type (Type of Stomatal Complex)
consist of three unequally sized subsidiary cells, which may nor be very distinct from ordinary epidermal cells
Indumentum
collective name for the thousands or millions of individual trichomes on a single plant
Trichome complement
the suire of trichome types of a species; valuable concept when trichomes examined as part of a taxanomic or ecological study
Nonglandular Trichome
trichomes not involved in secretion
Unicellular trichomes
consist of a single cell that projects above the surrounding surface; extremely common; cotton fibers are the long unicellular trichomes of the seed coat
Multicellular trichomes
may be long or short, with few or many cells, and they may be branched or unbranched
- Uniseriate - consists of one row of cells - Biseriate - consists of two rows of cells - Multiseriate - consists of many layers of cells;
Stellate hairs
highly branched, star-shaped trichomes
Candelabriform hairs
branching that looks like a candelabra: one central vine with individual branches along it
some look like complete trees.
Peltate hairs
airs - trichomes that look like complete trees
Peltate hairs - hairs that have a stalk on the disk/shield-shaped structure formed from branch cells interconnecting along their sides; are extremely complex and can be used to identify subfamily or occasionally even genus
Scales/Squamiform hairs
hairs without a stalk or with an extremely short stalk on the disk/shield-shaped structure formed from branch cells interconnecting along their sides.
Glandular trichomes
secretory trichomes
Stalk cells
contain transverse walls that have been found to contain a very high number of plasmodesmata, presumably to facilitate the flow of material to the head.
Foot/Basal cells
Transfer cells with labyrinthine walls adjacent to ordinary epidermal cells
Trochoplast/Piliferous cell
the short cell that grows out as a root hair when cells undergo unequal division.
Lithocysts
stone cell; large epidermal cells that contain crystallized calcium carbonate and protrude into the mesophyll of the plant
Cystolith
cell stone; complex crystal that results from the calcium carbonate, pectins, and silica
Long cells
ordinary epidermal cells found grouped with short cells in grass epidermises
Short cells
epidermal cells found grouped with long cells in grass epidermises that are modified into either silica or cork cells
-Silica cells
contain silica bodies with various shapes (round, elliptic, dumbbell, or saddle-shaped) that are extremely useful taxanomically and may also occur in other monocot families; the silica is not abundant until the cells begin to senesce
Cork cells
have walls encrusted with suberin, and their lumens are often filled with non protoplastic substances
Bulliform cells
large, thin-walled epidermal cells found in the epidermis of monocots that are thought to function in opening the leaf as it expands from the bud (leaf flexure); if they are turgid and swollen, the leaf is open and flat and if they lose water and become flaccid, the leaf folds, minimizing its exposed surface area.
Multiple Epidermis
when cells are derived from the outermost layer of the tunica undergo periclinal divisions to produce a structure with multiple layers, all with the same developmental origin.
Velamen
Velamin is a mutliple epidermis that covers the entire surface except for the extreme tip; cells are large, thick-walled, and dead at maturity;
It has been suggested that velamin is capable of absorbing and storing water and minerals from which the root cortex later gradually absorbs water.
Hypodermis
layers of cells derived from inner layers of tunica/corpus that develop special characteristics distinct from those of the inner cortex.
Root epidermis
does not develop from one distinct layer like shoot epidermis; it is a totally distinct tissue that is only functionally similar to the shoot epidermis (because each develop from their own distinct meristems)
Rhizodermis
renamed root epidermis; is simple, containing just ordinary epidermal cells and root hairs with a thin cuticle; no guard cells present (except in the pea) and apart from the root hairs, no other trichomes are present.
Epiblem - renamed root cortex
Electron-translucent
does not absorb stains for electron microscopy; characteristic of the middle lamella when guard cells enlarge to form a stomatal pore; may be due to the digestion of the middle lamella
Tip growth
in uniseriate trichomes; when root hair trichoblast begins to grow outward and only the very tip of the root hair is growing, all other parts being mature; it also occurs in other cylindrical cells (pollen tubes and funal hyphae); cytoplasm is aggregated into the tip, and there is a high concentration of dictysomes.
