In a closed ecosystem, 20 kg of plant biomass undergo photosynthesis over 8 hours and produces 12 kg of glucose. If the plants use 70% of the produced glucose for cellular respiration during the same period, what is the net amount of glucose that contributes to plant growth?

Step-by-step solution

1. Compute glucose used for respiration: 70% of 12 kg = 0.70 × 12 kg = 8.4 kg.
2. Subtract respiration glucose from total produced: 12 kg − 8.4 kg = 3.6 kg.
3. Report the net glucose available for plant growth as 3.6 kg.

Concept tested: Glucose consumption in cellular respiration

Published 13 October 2026 · How this solution was prepared and checked