AP BIOLOGY

Detailed explanation-1: -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. Secondary lignification is present in both cells.

Detailed explanation-2: -Tracheids are the water-conducting and mechanical supporting cells of gymnosperms; water is transported longitudinally through endplates and laterally through pits (a).

Detailed explanation-3: -Tracheids serve for support and for upward conduction of water and dissolved minerals in all vascular plants and are the only such elements in conifers and ferns.

Detailed explanation-4: -Water molecules move from the soil into living cells of the root, and eventually into the transport cells of the xylem, known as tracheids and vessels. These xylem cells are dead and hollow, allowing rapid water transport.

Detailed explanation-5: -Xylem tissues start as living cells, but as the cells mature, they undergo ordered deconstruction to help form the hollow tubes that make up the xylem vessels. The main function of the xylem vessels is to transport water in one upward direction from the roots, through the stem, and to the leaves.