Xylem serves as a conduit for the movement of water, minerals and phytohormones through a plant. Xylem is a vascular tissue, though its form varies from plant to plant.Know More
Three types of cells compose a plant's xylem. The most important cells, called tracheary elements, are hollow structures that serve as the passageway for water and other small molecules. Tracheary elements occur in two different forms, tracheids and vessel elements. Though both types have some differences, their essential function is similar. Both are dead before the plant rotates them into use.
The other two types of xylem cells are the parenchyma cells and fiber cells. The essential purpose of both types is to provide structure and support for the tracheary elements. Additionally, they prevent the plant's weight from crushing the tracheary elements, which would halt the flow of water.
Xylem is the most abundant biological material on the planet. It is present in the stalks of plants and flowers and makes up the woody part of trees. Scientists suspect that xylem evolved around the time that plants began colonizing terrestrial habitats. Unlike ancient plants that evolved in aquatic or marine ecosystems, surrounded by water, terrestrial plants had to evolve to transport water throughout the plant's various structures.Learn more in Diagnostics & Imaging
The main function of xylem cells is to carry water and soluble minerals from the root to the leaves of a plant. However, a secondary function of xylem tissue is to provide support for the plant. Xylem is present in vascular plants and is made up of different types cells, such as tracheids, fibers and parenchyma.Full Answer >
The function of a hospital is to provide surgical and medical care to the sick or disabled, according to Dictionary.com. About.com also notes that the role of a hospital is to deliver babies when needed on behalf of families. A hospital has more equipment, resources and space than a doctor's office when treating very ill patients and is able to accommodate patients for overnight stays.Full Answer >
Lung function tests are tests that help doctors diagnose asthma, states WebMD. Also called pulmonary function tests, these tests include a number of procedures to diagnose breathing problems. Spirometry and the methacholine challenge test are the two most common lung function tests.Full Answer >
Kidney function tests determine how effectively the kidneys are removing extra fluid and wastes from the blood, explains the National Kidney Foundation. Urine tests determine the swiftness of waste removal and if the kidneys are allowing anomalous amounts of protein to leak through.Full Answer >