Respiration in Plants — Predicted 2026

AI-Predicted Question Angles for UPSC 2026

Based on trend analysis, current affairs, and recurring themes in Respiration in Plants.

Detailed ATP Yield Calculation with Modern Values

high

NEET has historically asked about ATP yield. With the shift in accepted ATP values (from 36/38 to 30-32 ATP per glucose), questions are likely to test this updated understanding. Students might be asked to calculate the net ATP from specific stages or the overall process, requiring them to use the 2.5 ATP per NADH and 1.5 ATP per $FADH_2$ conversion factors. A question might also involve the cost of transporting cytoplasmic NADH into the mitochondria, which can reduce the total yield.

Interplay between Photosynthesis and Respiration

medium

While 'Respiration in Plants' is a distinct chapter, its relationship with 'Photosynthesis in Higher Plants' is fundamental. Questions might explore the complementary nature of these processes, net gas exchange in light vs. dark, or how products of one serve as substrates for the other. This tests a broader understanding of plant metabolism rather than isolated pathways. For example, a question might ask about the compensation point or the overall energy balance.

Regulation and Inhibitors of Respiration

low

While not as common, NEET can occasionally delve into the regulatory aspects or the effects of inhibitors on metabolic pathways. For respiration, questions could focus on allosteric regulation of key enzymes like phosphofructokinase, or the impact of specific inhibitors (e.g., cyanide affecting Complex IV of ETS) on ATP production and overall cellular function. This requires a deeper understanding beyond just memorizing the steps.

Respiratory Quotient (RQ) in Specific Physiological States

high

RQ is a consistently tested concept. Beyond simple calculations for pure substrates, questions might involve scenarios like germinating fatty seeds (RQ < 1), succulent plants during the day (RQ = 0 due to CAM pathway), or anaerobic respiration (RQ = infinite). This tests the application of RQ knowledge to real-world plant physiological conditions, requiring a nuanced understanding of substrate utilization.