NEET 2026 Botany Question 122 Solution

Photorespiration occurs prominently in C₃ plants when RuBisCO binds oxygen instead of carbon dioxide under high temperature, high O₂ concentration, and low CO₂ concentration. In contrast, C₄ plants have evolved a CO₂-concentrating mechanism (Kranz anatomy) which prevents photorespiration. Thus, statement (a) is definitively false.

• • Eliminates Option (1) and Option (4).

In photorespiration, RuBisCO functions as an oxygenase, consuming oxygen (O₂) and releasing carbon dioxide (CO₂). Statement (b) claims that "CO₂ is consumed and O₂ is generated", which is the exact opposite (normal photosynthesis). Hence, statement (b) is false.

• • Eliminates Option (3).

When RuBisCO oxygenates ribulose-1,5-bisphosphate (RuBP), the 5-carbon substrate is cleaved into one molecule of 3-carbon phosphoglycerate (3-PGA) and one molecule of 2-carbon 2-phosphoglycolate.

• • Statement (c) is factually correct.

NCERT states verbatim: "In the photorespiratory pathway, there is neither synthesis of sugars, nor of ATP. Rather it results in the release of CO₂ with the utilization of ATP. There is also no synthesis of NADPH." Therefore, statement (d) is factually correct.

• • Photorespiration is a biologically wasteful process.

Statements (c) and (d) are correct, while (a) and (b) are false. The correct option is Option (2).

• • Matches official NTA final answer key Option B / (2).