Question

In which of the following vascular bundles, the phloem occurs as two patches on either side of the xylem

• A. Collateral
• B. Bicollateral
• C. Radial
• D. Amphicribral

Answer 1

Answer: (B)

Bicollateral

If phloem is external to xylem, it is called as collateral as in many stems. If phloem is both external and internal to xylem, it is called as bicollateral as in leaves. Bicollateral vascular bundle is a primary vascular bundle where the phloem occurs on either side of the xylem. Phloem occurs above (external to) the metaxylem and also below (internal to) the protoxylem elements in this type of bundle in stems. In leaves, the phloem strands occur on either side of the xylem (adaxial and abaxial face of the bundle) in major veins in some families.

Thus, the correct answer is option B.