Question

As compared to a dicot root, a monocot root has:
(a) More abundant secondary xylem
(b) Many xylem bundles
(c) Inconspicuous annual rings
(d) Relatively thicker periderm

Answer 1

Hint: Roots of monocot and dicot plants differ in various aspects including the number as well as the arrangement of vascular tissue. The number of xylem bundles is also a major differentiating factor between the two types of roots.

Complete step by step answer:
The root system is an essential part of a plant body that is involved in the transportation of nutrients from the ground to other parts of plants wherever needed. Major differences in monocot and dicot root anatomy are as follows:

Monocot root	Dicot root
Pericycle gives rise to lateral roots only.	Pericycle gives rise to various parts of vascular cambium as well as lateral roots.
Vascular tissues such as xylem and phloem are excess in number.	Vascular tissues such as xylem and phloem are limited in number.
Xylem is round or oval in shape.	Xylem is angular or polygonal in shape.
Vascular tissues are more than 8 in number.	Vascular tissues are between 2 to 8 in number.
Pith is well developed and is larger in size.	Pith is either absent or incomplete.
Conjunctive tissue is of sclerenchymatous type.	Conjunctive tissue is of parenchymatous type.

So, the correct answer is ‘Many xylem bundles.’

Note: Xylem is tetrarch in dicot roots and polyarchy in monocot roots. Secondary growth is seen in dicot roots and not in monocot roots. It is due to the presence of cambium in dicot roots. Peanuts and beans are examples of dicot plants whereas, maize and palm are examples of monocot plants.