NEET2005BotanyPhotosynthesis in Higher PlantsActual
Assertion : C₄ photosynthetic pathway is more efficient than the C ₃ pathway. Reason : Photorespiration is suppressed in C ₄ plants.
Options
- AIf both assertion and reason are true and reason is the correct explanation of assertion
- BIf both assertion and reason are true but reason is not the correct explanation of assertion
- CIf assertion is true but reason is false
- DIf both assertion and reason are false.
Correct answer
A. If both assertion and reason are true and reason is the correct explanation of assertion
Step-by-step solution
C ₄ photosynthetic pathway is more efficient than C ₃ pathway as C ₄ plants can pick up CO ₂ even when it is found in low concentration. PEP enzymes shows high affinity for CO ₂ . C ₄ plants contain two types of chloroplast (Kranz anatomy) : bundle sheath chloroplast and mesophyll chloroplast. Bundle sheath cells contain Calvin cycle enzymes. Due to high concentration of CO ₂ in bundle sheath cells, RuBP carboxylase works only for Calvin cycle and not for photorespiration. Photorespiration is a wasteful process as