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.
Both xylem and phloem are vascular tissues found in a plant. Xylem is a tubular structure which is responsible for water transport from the roots towards all of the parts of the plant.hloem is a living tissue, composed of sieve tube cells, and its primary function is to transport nutrients (in sap) throughout the plant. As opposed to xylem which only transports water up the plant, phloem transports nutrients up or down, depending on where the nutrients are greatest.