Question

Select the mismatched pair out of the following

(A) Radial vascular bundle -	Xylem and phloem on different radii
(B) Bicollateral vascular bundle -	Phloem present on both sides of xylem
(C) Amphivasal vascular bundle -	Phloem surrounds xylem
(D) Conjoint vascular bundle -	Xylem and phloem on same radii

• A. A
• B. B
• C. C
• D. D

Answer 1

Answer: (C)

C

According to the relative position of xylem and phloem, the vascular bun­dles are classified -

1. Radial: Those in which the xylem and the phloem with different radii lie radically side-by-side (for example, in roots of seed plants). This is the most primitive type.

2. Bi-collateral: Those vascular bundles that contain two patches of phloem on either side of the xylem on the same radius.

3. Amphivasal - Those vascular bundles in which xylem surrounds the phloem tissue from all sides of the vascular bundle.

4. Conjoint - Those in which the two types of tissues are separated from one another. Here xylem and phloem together form a bundle.

Hence, (C) is the mismatched option.