Question

The $C_4$-plants are different from the $C_3$-plants with reference to the

• A. The substance that accepts $C{O}_2$ in carbon assimilation.
• B. Types of end product of photosynthesis.
• C. The number of NADPH that are consumed in preparing sugar.
• D. Types of pigments involved photosynthesis.

Answer 1

The correct option is A The substance that accepts $C{O}_2$ in carbon assimilation.

1. The CO${}_2$ acceptors in the C${}_3$ cycle is RuBP (Ribulose-1,5-bisphosphate), RuBP is a 5 carbon compound. The first CO${}_2$ acceptor in the C${}_4$ cycle is PEP (Phosphoenolpyruvate) which is a 3 carbon compound.
   
2. C${}_3$ plants do not have bundle sheath in leaves while C${}_4$ plants have.
3. First, stable product in C${}_3$ plants is 3 carbon compound while in C${}_4$ plant is 4 carbon compound.

So, the correct option is 'the substance that accepts CO2 in carbon assimilation.'