AP BIOLOGY

Detailed explanation-1: -The tissue responsible for the secondary growth in woody stems is the vascular cambium. Vascular cambium is found in between the xylem and phloem in woody stems, it produces xylem to the inside of the stem and phloem to the outside of the stem.

Detailed explanation-2: -The intercalary meristem is responsible for the increase in girth of the plant.

Detailed explanation-3: -In general, monocots do not undergo secondary growth. If they do increase in girth (like palm trees and yucca plants), it does not result in the development of a secondary xylem and phloem, since monocots don’t have vascular cambium. An increase in girth without secondary growth is referred to as anomalous thickening.

Detailed explanation-4: -the vascular cambium and the phellogen (cork cambium) is a common feature of the gymnosperms and dicotyledons. Among the monocotyledons, secondary growth is not so common and is realized by the activity of peculiarly different meristems.