Vitamins in lettuce are plentiful. Its fresh leaves are an excellent source of several Vitamin-A and Î²-carotenes. Just 100 g of fresh, raw-lettuce provides 247% of daily vitamin A, and 4443 Âµg of Î²-carotene (Carotenes convert into vitamin-A in the body; 2 Âµg of carotene is considered equivalent to 1 IU of vitamin-A).
Xylem is one of the two types of transport tissue in vascular plants, phloem being the other.he most distinctive xylem cells are the long tracheary elements that transport water. Tracheids and vessel elements are distinguished by their shape; vessel elements are shorter, and are connected together into long tubes that are called vessels. Xylem also contains two other cell types: parenchyma and fibers.
Phloem is used to transport dissolved substances, sap, around the plant, while xylem transports water. The transport system of plants differs from that of mammals in two distinct ways. Plant cells do not need substances as quickly as mammals because they are a lot less active.d. Phloem, and xylem, tissue is arranged so that cells join end to end to form long tubes throughout the plant. The cells that make up the transport system have been modified to allow easier transport through the plant. In xylem tissue, the cells are dead.