Question

Which one does not differ between a ${\text{C}}_3$ and a ${\text{C}}_4$ plant?
$I.$ Initial ${\text{CO}}_2$ acceptor
$II.$ Extent of photorespiration
$III.$ Enzyme catalyzing reaction that fixes ${\text{CO}}_2$
$IV.$ Presence of Calvin cycle
$V.$ Leaf anatomy

• A. $I$ and $V$
• B. $V$
• C. $II$ and $III$
• D. $II$

Answer 1

The correct option is B $V$

The initial ${\text{CO}}_2$ receptor is RuBP for ${\text{C}}_3$ plants whereas phosphoenolpyruvate for ${\text{C}}_4$ plants. Photorespiration losses are high in ${\text{C}}_3$ whereas low in ${\text{C}}_4$ plants.
Calvin cycle is a dark reaction which occurs in both ${\text{C}}_3$ and ${\text{C}}_4$ plants.
${\text{C}}_4$ plants have specialized kranz anatomy of leaves which is not present in ${\text{C}}_3$ plants.
Thus, the correct answer is option 'b'.