Question

Give comparison between the following: Anatomy of leaf in C3 and C4 plants

Answer 1

Part 1:Introduction

• The plants which use C3 carbon fixation pathway and the first product of carbon dioxide fixation is a 3-carbon organic compound, 3-phosphoglycerate, are termed as C3 plants.
• The plants in which the first product of carbon dioxide fixation is a 4-carbon organic compound, oxaloacetate, are termed as C4 plants.

Part 2 :Anatomy of leaf – C4 plants

• The arrangement of mesophyll and bundle sheath cells in the leaf of C4 plants is different from C3 plants.
• The parenchymatous cells which are a type of ground tissue present in the leaf are called mesophyll cells. The cells surrounding the vascular bundles is called the bundle sheath cells.
• In C4 plant these mesophyll cells are clustered around the bundle sheath cells and forms a shape which is similar to the wreath.
• This arrangement seen in the leaf of C4 plants is called Kranz anatomy.
• In C3 plants the mesophyll cells are not clustered and they do not exhibit Kranz anatomy .

Part 3:Chloroplast

• In C3 plants chloroplast are present only in the mesophyll cells.
• In C4 plants chloroplasts are present in bundle sheath as well as mesophyll cells.

C3 vs C4 plants
$\begin{array}{ccc}\text{Criteria}& \text{C3 plants}& \text{C4 plants}\\ \text{Anatomy}& \text{Kranz anatomy absent.}& \text{Kranz anatomy present.}\\ \text{Mesophyll cells}& \text{Mesophyll cells have intercellular space.}& \text{Mesophyll cells do not have intercellular space.}\\ \text{Chloroplast}& \text{Chloroplasts are found only in mesophyll cells.}& \text{Chloroplasts are found in both mesophyll and bundle sheath cells.}\end{array}$