Question

4. Draw illustrations to bring out anatomical difference between

(a) Monocot root and dicot root

(b)Monocot stem and dicot stem

Answer 1

(a)Monocot root and dicot root

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

(b)Monocot stem and dicot stem

$\begin{array}{ccc}\text{S.No}& \text{Monocot Stem}& \text{Dicot Stem}\\ 1& \text{Dumb bell-shaped guard cells in stomata}& \text{Kidney-shaped gurad cells present}\\ & \text{occuring in epidermis}.& \text{in stomata in epidermis}.\\ 2& \text{Ground tissue is uniform and}& \text{Ground tissue is differentiated}\\ & \text{there is no differentiation.}& \text{into cortex, endodermis, pericycle and pith.}\\ 3& \text{The vascular bundles are scattered in ground}& \text{The vascular bundles are}\\ & \text{tissue many in number and vary in size}.& \text{arranged in a ring.}\\ 4& \text{Normally no secondary growth}& \text{Secondary growth}\\ & \text{occurs, few exceptions,e.g. Aloe.}& \text{takes place.}\\ 5& \text{The primary vascular tissues remains}& \text{The older vascular tissues cease functioning}\\ & \text{functional throughtout the life of the plant.}& \text{sometimes are replaced by new ones.}\\ 6& \text{There is little increase in size.}& \text{The stem also increase in diameter}\\ & & \text{with age due to secondary growth.}\end{array}$