AP BIOLOGY

Detailed explanation-1: -Cell division by the cambium produces cells that become secondary xylem and phloem. As secondary phloem and xylem tissue accumulates, it both increases the girth of the stem and forms wood and bark.

Detailed explanation-2: -During secondary growth, the medullary rays adjacent to the intrafascicular cambium develop into meristematic tissue and are called interfascicular cambium. Both intrafascicular and interfascicular cambiums form a continuous ring called a cambial ring.

Detailed explanation-3: -The vascular cambium produces secondary xylem on the inside of the ring, and secondary phloem on the outside, pushing the primary xylem and phloem apart. The vascular cambium usually consists of two types of cells: Fusiform initials (tall, axially oriented)

Detailed explanation-4: -(Recall that xylem is located toward the interior and phloem toward the exterior of the bundle.) The cells of the vascular cambium divide and form secondary xylem (tracheids and vessel elements) to the inside, and secondary phloem (sieve elements and companion cells) to the outside.

Detailed explanation-5: -toward the inside are called secondary xylem, or wood, and those formed toward the outside of the cambium are called secondary phloem. The bark and the wood together constitute the secondary plant body of the tree. The woody vascular tissue provides both longitudinal and transverse movement for carbohydrates and water.