question_answer 4)

Draw illustrations to bring out the anatomical differences between (a) Monocot root and dicot root (b) Monocot stem and dicot stem

Answer:

(a) Differences between Monocot and Dicot root  

S. No.	Monocot Root	Dicot Root
1.	Cortex is very wide.	Cortex is comparatively narrow.
2.	Outer cortex is usually differentiated into exodermis.	Outer cortex is usually not differentiated into exodermis.
3.	Endodermis contains prominent casparian strips only in young roots,	Endodermis contains prominant casparian strips.
4.	Xylem and phloem bundles are many in number 8 or more.	Xylem and phloem bundles vary in number from 2-6.
5.	Metaxylem vessels are oval or rounded.	Metaxylem vessels generally angular.
6.	No secondary growth.	Secondary growth takes place.
7.	Pith is large and well-developed.	Pith is small or absent.

    (b) Differences between Monocot and Dicot stem

S. No.	Monocot Stem	Dicot Stem
1.	Dumb bell-shaped guard cells in stomata occurring in epidermis.	Kidney-shaped guard cells present in stomata in epidermis.
2.	Ground tissue uniform and there is not any differentiation.	Ground tissue differentiated into cortex, endodermis, pericycle and pith.
3.	The vascular bundles are scattered in ground tissue many in number and vary in size.	The vascular bundles are arranged in a ring.
4.	Normally, no secondary growth occurs, few exceptions, e.g., Aloe, etc.	Secondary growth takes place.
5.	The primary vascular tissues remains functional throughout the life of the plant.	The older vascular tissues cease functioning after sometimes are replaced by new ones.
6.	There is little increase in size.	The stem also increase in diameter with age due to secondary growth.