AP BIOLOGY

Detailed explanation-1: -The activity of the vascular cambium gives rise to annual growth rings. During the spring growing season, cells of the secondary xylem have a large internal diameter and their primary cell walls are not extensively thickened.

Detailed explanation-2: -When a tree is cut down, kids love to run and count the rings on the stump to see how old the tree was. The general rule of thumb is that one ring stands for one year, or one season of growth. A surprisingly accurate old tale, these rings are the result of cell division within the cambium layer of the woody stem.

Detailed explanation-3: -Main function – upwards water transport. The xylem, vessels and tracheids of the roots, stems and leaves are interconnected to form a continuous system of water-conducting channels reaching all parts of the plants. The system transports water and soluble mineral nutrients from the roots throughout the plant.

Detailed explanation-4: -The cambium cells on the outside become part of the tree’s phloem, a band of inner bark through which the tree’s food supply moves. The cambium cells on the inside become the xylem, a system of tiny tubelike cells that carry the tree’s water supply. These xylem layers give us the annual rings.

Detailed explanation-5: -growth ring, in a cross section of the stem of a woody plant, the increment of wood added during a single growth period. In temperate regions the growth period is usually one year, in which case the growth ring may be called an “annual ring.” In tropical regions, growth rings may not be discernible or are not annual.