Question

Exarch and polyarch vascular bundles occur in:

• A. Dicot root
• B. Monocot root
• C. Dicot stem
• D. Monocot stem

Answer 1

The correct option is B Monocot root

Exarch is used when there is more than one strand of primary xylem in a stem or root, and the xylemdevelops from the outside inwards towards the center, i.e. centripetally. The metaxylem is thus closest to the center of the stem or root and the protoxylem closest to the periphery.

In monocot root, vascular bundles are radial in arrangement. There are eight bundles each of xylem and phloem. Hence, the condition is described as polyarch.