Question

In stem, vascular cambium and cork cambium form secondary tissues respectively in which region:

• A. Cortical region and vascular region
• B. Intrastelar region and extrastelar region
• C. Both in stelar region
• D. Both in cortical region

Answer 1

The correct option is B Intrastelar region and extrastelar region

Stele is the central region of stem and has vascular bundles. During secondary growth, there is an increase in the girth of the plant body. Secondary growth occurs both in intrastelar and extrastelar region. Secondary growth takes place in intrastelar region due to the activity of vascular cambium. The vascular cambium produces secondary xylem and secondary phloem. Secondary growth takes place in extrastelar region (cortical region) due to the activity of cork cambium/phellogen. Phellogen produces secondary tissues like phellem and phelloderm.