Secondary xylem is produced by the vascular cambium during secondary growth in woody plants. It is responsible for the increase in the girth of stems and roots and constitutes the bulk of the wood in trees and shrubs.
1022
Which meristematic tissue is responsible for the production of bark on the surface of woody stems?
The phellogen, also known as the cork cambium, is a lateral meristem responsible for secondary growth in the periderm. It produces cork (phellem) towards the outside and phelloderm towards the inside. This activity results in the formation of the outer bark, which serves as a protective layer for the stem, replacing the epidermis as the plant increases in girth.
1023
Which tissue layer is located as a narrow strip between the xylem and phloem in vascular bundles?
The cambium is a layer of meristematic tissue found between the xylem and phloem in vascular plants. It is responsible for secondary growth, producing secondary xylem towards the inside and secondary phloem towards the outside. This activity increases the girth of the stem or root over time.
1024
The production of cork is a characteristic feature of which developmental process?
Cork production, or phellogenesis, is a key component of secondary growth in woody plants. It occurs when the cork cambium (phellogen) produces cork cells (phellem) toward the outside of the stem or root. This process replaces the epidermis with a protective, water-impermeable layer, which is essential for the survival and structural integrity of perennial plants as they increase in girth.
1025
Which specific tissue is responsible for secondary growth in plants?
Secondary growth, which results in an increase in the girth or thickness of the plant stem and root, is facilitated by lateral meristems. The vascular cambium is the primary lateral meristem that produces secondary xylem (wood) and secondary phloem, allowing the plant to increase in diameter over time.
1026
Which type of plant growth is primarily facilitated by the activity of the vascular cambium?
The vascular cambium is a lateral meristem responsible for secondary growth in plants. By producing secondary xylem (wood) towards the inside and secondary phloem towards the outside, it increases the girth or diameter of the stem and root, allowing for structural support and increased transport capacity in woody plants.
1027
How many systems of organization are typically found in secondary xylem?
Secondary xylem is organized into two distinct systems: the axial (or vertical) system and the radial (or horizontal) system. The axial system consists of tracheids, vessels, and fibers that conduct water vertically, while the radial system consists of xylem rays that facilitate the lateral transport of water and nutrients across the stem.
1028
Which type of plant growth is primarily associated with the activity of the vascular cambium?
Secondary growth in plants refers to the increase in thickness or girth of the stem and root. This process is driven by the activity of lateral meristems, specifically the vascular cambium and the cork cambium. The vascular cambium produces secondary xylem (wood) internally and secondary phloem externally, leading to the expansion of the plant body in diameter, which is characteristic of woody dicots and gymnosperms.
1029
What are the two primary systems found in secondary xylem?
Secondary xylem is organized into two systems: the axial (vertical) system, which transports water vertically and provides support, and the radial (ray) system, which facilitates the lateral transport of water and nutrients across the stem or root.
1030
Is secondary growth present or absent in the stems of monocotyledonous plants?
Monocotyledonous plants generally lack secondary growth because they do not possess a functional vascular cambium. In dicots, the vascular cambium allows for the production of secondary xylem and phloem, leading to an increase in stem girth. Since monocots lack this meristematic tissue, their stems remain relatively uniform in diameter throughout their life cycle. This anatomical difference is a primary factor in the structural limitations of monocot growth compared to woody dicots.
