Question

Select the correct pair

• A. Loose parenchyma cells rupturing the epidermis and forming a lens shaped opening in bark - Spongy parenchyma
• B. parenchyma cells in the epidermis of grass leaves - Subsidiary cells
• C. In dicot leaves, vascular bundles are surrounded by large thick-walled cells - Conjunctive tissue
• D. Cells of medullary rays that form part of cambial ring - Interfascicular cambium

Answer 1

The Correct Option is D

In woody plants, the vascular cambium is responsible for secondary growth, leading to the development of secondary xylem (wood) and secondary phloem. The vascular cambium consists of two components: the fascicular cambium and the interfascicular cambium.

• The fascicular cambium is found within the vascular bundles and is responsible for the production of new xylem and phloem cells within the bundles themselves.
• The interfascicular cambium is located between the vascular bundles and is responsible for the formation of new xylem and phloem cells that connect the individual vascular bundles. These interfascicular cambium cells are often associated with medullary rays, which are radial files of parenchyma cells that extend from the pith to the bark.

So, option (D) correctly identifies that the cells of medullary rays are part of the interfascicular cambium, which is responsible for connecting the vascular bundles in a plant's stem and allowing for the growth of secondary tissues between the bundles.