What part of plant jeeps the plant stiff?
436437
The stem of a plant is made of cellulose and lignin, tough fibers that can hold the plant up
557413
(m)\n\nThe coleoptiles of grasses (like that of oat, the Avena - coleoptile) are popular test objects of plant physiology. A growing coleoptile that is illuminated unilaterally does grow towards the light source. This behaviour is common among plants and is known as phototropism. C. DARWIN (assisted by his son Francis DARWIN) attributed in his work "The Power of Movement in Plants" (1880) a decisive function in the recognition of a light stimulus to the coleoptile’s tip, and he observed that the actual bending occurs in a zone below the tip. He concluded that a transmission of impulse had to take place in the tissue. Studies of plant anatomical nature revealed that the growth towards light is caused by an elongation of the cells at the side that is shielded from the light. The phototropic reaction does not happen if the coleoptile’s tip is removed, though it can be induced again by the replacement of the tip. This indicates the existence of a substance that is spread from tip to bottom (basipetal direction) and that causes the elongation. \n\nThe Danish botanist P. BOYSEN-JENSEN interrupted the assumed substance flow by inserting a mica sheet into the shielded side thus separating the coleoptile’s tip from the tissue below (1913). The water-impermeable sheet interrupted the phototropic reaction. Consequently occurs no transport of the effector around the small tile. The phototropic reaction remained intact when the mica sheet was inserted into the illuminated side or along the coleoptile’s vertical axis. \n\nIn the late twenties was the material nature of the effector finally proved by the Dutch plant physiologist F. WENT. He assumed that a substance that flows from tip to bottom should also flow through a small cube of agar. In order to test his assumption did he place cut coleoptile tips with the cutting side on top of small cubes of agar. Some time later did he remove the tips and placed the agar cubes that he believed to contain the effector onto the decapitated coleoptiles
79800
wikipedia comes to mind or do a Yahoo search. Put "plant anatomy" and "plant fiber" in quotes.
950404
Kangaroo paw. ( horrible looking flower)     :-)
795028
spines ( really curled up leaves)
912534
The buttocks. Even though cracked it takes a lot of crap and keeps on working. It is so stable that in many countries they bury people with their buttocks sticking out of the ground and then use them for bicycle racks.
786061
Homeostasis.\n\nFor more specifics about plants look at the bottom of the second source.
718376
It's a plant with deep roots that draws its water supply from a water table.
711385
It's a fern, a non-flowering plant.
593033
cell walls keep the cell rigid, so they can stay upright.\n\ncuticles reduce water loss through evaporation, preventing the plant from being dehydrated
125429
the photosynthesis makes food for the rest of the plant transported by phloem. the movement of a plant towards light is phototropism
374688
The relative rigidity of the cell wall renders plants sedentary, unlike animals, whose lack of this type of structure allows their cells more flexibility, which is necessary for locomotion. The plant cell wall serves a variety of functions. Along with protecting the intracellular contents, the structure bestows rigidity to the plant, provides a porous medium for the circulation and distribution of water, minerals, and other nutrients, and houses specialized molecules that regulate growth and protect the plant from disease.(plants do not have an immunity system, and cell wall is a good barrier)
824720
c-both apical and lateral meristems
665052
Plants, i think. look in a dictionnary or online.
113762
I have a plant sitting in my office.  I would say it is about 8.5 to 9 feet.  That is my closest plant.
1179455
Animals have a circulatory system that transports fluids, chemicals, and nutrients around within the animal body. Some plants have an analogous system: the vascular system in vascular plants; trumpet hyphae in bryophytes.\n\nRoot hairs are thin-walled extensions of the epidermal cells in roots. They provide increased surface area and thus more efficient absorption of water and minerals. Water and dissolved mineral nutrients enter the plant via two routes. \n\n\nWater and selected solutes pass through only the cell membrane of the epidermis of the root hair and then through plasmodesmata on every cell until they reach the xylem: intracellular route (apoplastic). Water and solutes enter the cell wall of the root hair and pass between the wall and plasma membrane until the encounter the endodermis, a layer of cells that they must pass through to enter the xylem: extracellular route (symplastic). \n\n\nThe endodermis has a strip of water-proof material (containing suberin) known as the Casparian strip that forces water through the endodermal cell and in such a way regulates the amount of water getting to the xylem. Only when water concentrations inside the endodermal cell fall below that of the cortex parenchyma cells does water flow into the endodermis and on into the xylem.\nXylem and Transport \nXylem is the water transporting tissue in plants that is dead when it reaches functional maturity. Tracheids are long, tapered cells of xylem that have end plates on the cells that contain a great many crossbars. Tracheid walls are festooned with pits. Vessels, an improved form of tracheid, have no (or very few) obstructions (crossbars) on the top or bottom of the cell. The functional diameter of vessels is greater than that of tracheids.\n\nWater is pulled up the xylem by the force of transpiration, water loss from leaves. Mature corn plants can each transpire four gallons of water per week. Transpiration rates in arid-region plants can be even higher. Water molecules are hydrogen bonded to each other. Water lost from the leaves causes diffusion of additional water molecules out of the leaf vein xylem, creating a tug on water molecules along the water columns within the xylem. This "tug" causes water molecules to rise up from the roots to eventually the leaves. The loss of water from the root xylem allows additional water to pass throught the endodermis into the root xylem.\n\nCohesion is the ability of molecules of the same kind to stick together. Water molecules are polar, having slight positive and negative sides, which causes their cohesion. Inside the xylem, water molecules are in a long chain extending from the roots to the leaves. \n\nAdhesion is the tendency of molecules of different kinds to stick together. Water sticks to the cellulose molecules in the walls of the xylem, counteracting the force of gravity and aiding the rise of water within the xylem. \n\nCohesion-Adhesion Theory\nTranspiration exerts a pull on the water column within the xylem. The lost water molecules are replaced by water from the xylem of the leaf veins, causing a tug on water in the xylem. Adhesion of water to the cell walls of the xylem facilitates movement of water upward within the xylem. This combination of cohesive and adhesive forces is referred to as the Cohesion-Adhesion Theory.\n\n\nGuard Cells Regulate Transpiration\nIn most environments, the water concentration outside the leaf is less than that inside the leaf, causing a loss of water through openings in the leaf known as stomata (singular = stoma). Guard cells are crescent-shaped cells of the epidermis that flank the stoma and regulate the size of the opening. Together, the guard cells and stoma comprise the stomatal apparatus. The inner wall of the guard cell is thicker than the rest of the wall. When a guard cell takes up potassium ions, water moves into the cell, causing the cell to become turgid and swell, opening the stoma. When the potassium leaves the guard cell, the water
309468
Water travels through a network of 'veins' through out the plant. The cells are re-hydrated which causes them to expand like a balloon. Once the cells are all filled to capacity, they rest on each other. The cell membranes contain cellulose that helps them stand erect when fully hydrated.