AP BIOLOGY

Detailed explanation-1: -A vessel element or vessel member (also called trachea or xylem vessel) is one of the cell types found in xylem, the water conducting tissue of plants. Vessel elements are typically found in angiosperms (flowering plants) but absent from most gymnosperms such as conifers.

Detailed explanation-2: -Xylem vessel elements have thick secondary cell walls (SCWs), which are composed of cellulose, hemicellulose, and lignin (Turner et al. 2007). These thick SCWs are the major source of woody biomass and represent a valuable source of renewable energy (Yang et al. 2013).

Detailed explanation-3: -Xylem can be found: in vascular bundles, present in non-woody plants and non-woody parts of woody plants. in secondary xylem, laid down by a meristem called the vascular cambium in woody plants. as part of a stelar arrangement not divided into bundles, as in many ferns.

Detailed explanation-4: -Tracheids and vessels are the components of the complex xylem tissue. Both help in conduction of water along the stem and provide mechanical support to the plant. Both cells are tubular.

Detailed explanation-5: -Vessel elements are cells in phloem tissue that are technically dead. Upon maturation, the living material in the cells disappears while the cell wall remains; the cells are dead; however, sieve tube elements contain living tissue.