Question

Amphicribal vascular bundles are

• A. Endarch
• B. Exarch
• C. Mesarch
• D. All of the above

Answer 1

Answer: (C)

Mesarch

Vascular bundles are classified according to the spatial relation of xylem and phloem. The presence of xylem and phloem in the same bundle surrounding each other is referred to as a concentric bundle. They are classified as amphicribal and amphivasal vascular bundles. The presence of xylem in the centre surrounded by phloem is described as amphicribal (or hadrocentric). The presence of phloem in the centre surrounded by xylem is described as amphivasal (or leptocentric). In amphicribal vascular bundles, protoxylem first develops in the centre of the strand and continues to develop both centrifugally and centripetally. This condition is termed as mesarch. Thus, the correct answer is option C.