Name the various type of cells present in xylem . What are their function of this tissue
Answers
Answer:Vascular tiisue system of the plant helps in the transportation of water and food in the plant. Xylem – This tissue helps in the transport of water and dissolved substances throughout the plant. The different components of the xylem include tracheids, vessels, xylem parenchyma and xylem fibres. *Tracheids form the main conductive cells of some non-flowering plants. Water moves from the cell to cell through side walls. These cells aer elongated cells with tapering ends. These cells with cell walls bear spiral, pitted or bordered-pitted thickenings. *Vessels are advanced water conductive elements mostly seen in flowering plants. The cell walls are thickened with lignin. These provide rigidity and resistance to the cell walland prevents it from collapsing during excess transpiration. *Xylem parenchyma are the living cells of the xylem. They perform functions like secretion and storage. *Xylem fibres are midway between tracheids and xylem parenchyma (libriform fibres). They provide lot of support to the plants.
Explanation:
Answer:
Xylem
Xylem originates from the Greek word “xylon” that means wood. Nigeli coined the word xylem. Xylem is a type of vascular tissue present in plants, which primarily transports water and nutrients from roots to stem and leaves. They also provide mechanical strength to the plants.
On the basis of origin there are two types of xylem cells:
Primary xylem: originating from procambium, further divided into protoxylem and metaxylem
Secondary xylem: originating from the vascular cambium
Xylem is composed of four different kinds of elements:
Tracheids: Dead, tube-like cells with a tapering end. They are present mostly in gymnosperm and lower angiosperm. They have a thick lignified wall and lack protoplasm. Their main function is water and mineral transportation
Vessels: They are present in angiosperms. These are a long cylindrical structure having tube-like appearance. The walls are lignified and have a large central cavity. They are also dead and lack protoplasm. They have many cells called vessel members which are interconnected through a perforation in common walls. Mostly involved in the conduction of water, minerals and give mechanical strength to the plant
Xylem Fibre: Dead cell with lignified walls and a central lumen. Involved in water transportation and providing mechanical support
Xylem Parenchyma: Only living cells of xylem and store starch and fat. They assist in the short distance transportation of water