Question

In $C_{4}$ plants, photorespiration does not occur. $C_{4}$ plants have a mechanism that increases the concentration of $CO_{2}$ at the enzyme site.

• A. If both assertion and reason are true and reason is the correct explanation of assertion
• B. If both assertion and reason are true but reason is not the correct explanation of assertion
• C. If assertion is true but reason is false
• D. If both assertion and reason are false

Answer 1

Answer: (A)

If both assertion and reason are true and reason is the correct explanation of assertion

Answer 2

In $C_{4}$ plants photorespiration does not occur because they have a mechanism that increases the concentration of $CO_{2}$ at the enzyme site. This takes place when the $C_{4}$ acid from the mesophyll is broken down in the bundle sheath cells to release $CO_{2}$. This results in increasing the intracellular concentration of $CO_{2}$. This ensures that the $RuBisCO$ functions as a carboxylase, thus, minimising the oxygenase activity.