Quite a lot of interest is what is the basis of life of simple leaves falling from trees. What is a vein? What provides them with good water supply? We will answer this and other questions a bit later!
What is a leaf?
Leaf - in botany, this is the external apparatus of the plant, the main functions of which are synthesis, gas exchange and evaporation. In order to provide the cells with an azo pigment element, the leaf has a plate-like texture. The leaf, in addition, is considered to be the organ of respiration, volatilization and gutting (separation of water particles) of plants. Leaves have every chance of retaining water and high-calorie elements, while other plants carry out other functions.
What does the sheet consist of?
Typically, the structure of the leaf is in the following materials:
- The epidermis is a layer of cells that protects against the harmful effects of the external environment and excessive volatilization of water. Often on top of the epidermis, the leaf is shrouded in a protective layer of a waxy material (cuticle).
- Mesophyll is an internal chlorophyll-bearing material that performs the main function - photosynthesis.
- A network of leaf veins intellectually gathering in bundles (conductive matter) are formed in blood vessels and sieve tubes. They are designed to achieve the goal of moving water, dissolving salts, sugars and automatic components.
- Stomata are specialized complex cell complexes located in the main plane of leaflets; with their help self-evaporation of excess water (evaporation) and gas exchange are performed.
What is a vein?
Veins - we can say that this is the "circulatory system" of the leaf, according to which the sheets can receive moisture and rottizit elements. They also accompany the receipt of basic elements during photosynthesis. Distinguish synchronous, arterial (practically only in monocotyledonous plants), palmate nerve and peristemia (in dicotyledonous plants) nerves. Leaves with a well-formed network of small veins are called reticular. Veins are also found in the sepals, petals, embryos and stems of plants. The type of venation is often a significant regular criterion.
Veins of many species of insects are of almost the same nature. Veins in insects are hollow cylindrical sclerotized thickened plates in the wing, into which branches of the tracheal trunks and nerves are directed. They guarantee the reliability of the wing and are the only type of this property.