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The epidermis (from the Greek ἐπιδερμίς, meaning "over-skin") is a single layer of cells that covers the leaves, flowers, roots and stems of plants. It forms a boundary between the plant and the external environment. The epidermis serves several functions: it protects against water loss, regulates gas exchange, secretes metabolic ...
The underside of a leaf. In this species ( Tradescantia zebrina) the guard cells of the stomata are green because they contain chlorophyll while the epidermal cells are chlorophyll-free and contain red pigments. In botany, a stoma ( pl.: stomata, from Greek στόμα, "mouth"), also called a stomate ( pl.: stomates ), is a pore found in the ...
Plant stem. This above-ground stem of Polygonum has lost its leaves, but is producing adventitious roots from the nodes. A stem is one of two main structural axes of a vascular plant, the other being the root. It supports leaves, flowers and fruits, transports water and dissolved substances between the roots and the shoots in the xylem and ...
Trichome. Fossil stellate hair (trichome) probably of an oak, in Baltic amber; image is about 1 mm wide. Trichomes ( / ˈtraɪkoʊmz, ˈtrɪkoʊmz /; from Ancient Greek τρίχωμα (tríkhōma) ' hair ') are fine outgrowths or appendages on plants, algae, lichens, and certain protists. They are of diverse structure and function.
Plant cells are the cells present in green plants, photosynthetic eukaryotes of the kingdom Plantae. Their distinctive features include primary cell walls containing cellulose, hemicelluloses and pectin, the presence of plastids with the capability to perform photosynthesis and store starch, a large vacuole that regulates turgor pressure, the ...
The epidermis is composed of multiple layers of flattened cells [4] that overlie a base layer ( stratum basale) composed of columnar cells arranged perpendicularly. The layers of cells develop from stem cells in the basal layer. The thickness of the epidermis varies from 31.2μm for the penis to 596.6μm for the sole of the foot with most being ...
Onion epidermal cell. These large cells from the epidermis of a red onion are naturally pigmented. The epidermal cells of onions provide a protective layer against viruses and fungi that may harm the sensitive tissues. Because of their simple structure and transparency they are often used to introduce students to plant anatomy [ 1] or to ...
Sclerenchyma is the tissue which makes the plant hard and stiff. Sclerenchyma is the supporting tissue in plants. Two types of sclerenchyma cells exist: fibers cellular and sclereids. Their cell walls consist of cellulose, hemicellulose, and lignin. Sclerenchyma cells are the principal supporting cells in plant tissues that have ceased elongation.