Search results
Results from the WOW.Com Content Network
English: xylem (blue) carries water from the roots upwards phloem (orange) carries products of photosynthesis from the place of their origin (source) to organs where they are needed (roots, storage organs, flowers, fruits – sink); note that e.g. the storage organs may be source and leaves may be sink at the beginning of the growing season
Xylem is one of the two types of transport tissue in vascular plants, the other being phloem; both of these are part of the vascular bundle. The basic function of the xylem is to transport water upward from the roots to parts of the plants such as stems and leaves, but it also transports nutrients .
In trees, the phloem is the innermost layer of the bark, hence the name, derived from the Ancient Greek word φλοιός (phloiós), meaning "bark". [3] [4] The term was introduced by Carl Nägeli in 1858. [5] [6] Different types of phloem can be distinguished. The early phloem formed in the growth apices is called protophloem.
Xylem is the water-conducting tissue, and the secondary xylem provides the raw material for the forest products industry. [26] Xylem and phloem tissues each play a part in the conduction processes within plants. Sugars are conveyed throughout the plant in the phloem; water and other nutrients pass through the xylem.
Xylem moves water and mineral ions in the plant and phloem accounts for organic molecule transportation. Water potential plays a key role in a plant's nutrient uptake. If the water potential is more negative in the plant than the surrounding soils, the nutrients will move from the region of higher solute concentration—in the soil—to the ...
Mosses are examples of non-vascular plants. Non-vascular plants are plants without a vascular system consisting of xylem and phloem. Instead, they may possess simpler tissues that have specialized functions for the internal transport of water. [citation needed] Non-vascular plants include two distantly related groups:
3. Xylem I 4. Phloem I 5. Sclerenchyma 6. Cortex 7. Epidermis. In botany, a cortex is an outer layer of a stem or root in a vascular plant, lying below the epidermis but outside of the vascular bundles. [1] The cortex is composed mostly of large thin-walled parenchyma cells of the ground tissue system and shows little to no structural ...
According to the hypothesis, the high concentration of organic substances, particularly sugar, inside the phloem at a source such as a leaf creates a diffusion gradient (osmotic gradient) that draws water into the cells from the adjacent xylem. This creates turgor pressure, also called hydrostatic pressure, in the phloem. The hypothesis states ...