Question

Type of vascular bundles in fern roots

• A. Hadrocentric
• B. Lepotcentric
• C. Conjoint collateral
• D. Radial

Answer 1

The correct option is D Radial

Radial vascular bundle - In these types of vascular bundles, xylem and phloem tissues occur in separate groups on alternate radial positions. This is seen in roots. Collateral vascular bundles are very common type and seen in stems of dicotyledons except the members of Cucurbitaceae and some members of Convolvulaceae. Cambium may be present or absent in between xylem and phloem patches making the vascular bundle open or closed respectively. When xylem surrounds the phloem tissue from all sides the vascular bundle is called amphivasal vascular bundle or leptocentric type. Such bundles are seen in monocot plant like Dracaena after secondary growth. When phloem surrounds the xylem tissue entirely, the vascular bundle is called amphicribral vascular bundle or hadrocentric type. Such vascular bundles are seen in pteridophytes like Lycopodium, Selaginella. So, radial vascular bundles are present in all roots. Thus, option D is correct.