AP BIOLOGY

Detailed explanation-1: -Wood is the secondary xylem produced by coniferous gymnosperms (conifers) and by dicotyledonous angiosperms (flowering plants). Wood performs two main physiological functions: it conducts water from the roots to the leaves and it supports the branches and crown of trees and shrubs.

Detailed explanation-2: -The inner layer of secondary xylem forms the heartwood and the outer layer forms the sapwood. The sapwood contains young layers of the tree and it performs water conduction in large woody trees. Thus, the common name of wood is called secondary xylem.

Detailed explanation-3: -Wood is a product of secondary growth in a plant. This secondary growth arises from the vascular cambium, which creates secondary vascular bundles (i.e. secondary xylem and phloem) after initial cell elongation and growth of a plant has ceased. Wood is mainly composed of the secondary phloem.

Detailed explanation-4: -Wood is secondary xylem consisting largely of dead cells involved in the transport of water and minerals as well as support. a. Plants grow in length because of the elongation of cells produced by terminal (apical) meristems.

Detailed explanation-5: -Wood is secondary xylem and often characterized as “dead tissue” because the conduits for water transport-vessels and tracheids-are dead at maturity, as are the fiber cells in many angiosperms.