Green plants in a terrestrial ecosystem capture about ____ of the sunlight…

Concept

Primary producers convert radiant solar energy into chemical energy stored in organic food through photosynthesis.

Photosynthetic capture efficiency is the ratio of chemical food energy stored to incident sunlight energy, expressed as a percentage. It is distinct from the efficiency of energy transfer between trophic levels.

Application

1. The blank asks for the initial capture of sunlight by green leaves in a terrestrial ecosystem.

2. The standard NCERT convention for this initial capture is about 1% of the incident sunlight.

3. Thus, for every 100 units of sunlight falling on the leaves, about 1 unit is converted into chemical food energy.

Contrast

• A 5% capture rate would store 5 energy units per 100 incident units, which is five times the stated textbook estimate.

• A 2% capture rate would store 2 energy units per 100 incident units, which is twice the stated textbook estimate.

• “More than one of the above” would require at least two numerical rates to satisfy the same single-value approximation.

• “None of the above” would require the textbook estimate to be absent from the numerical choices.

Cross-check

The approximately 1% initial solar-energy capture by producers should not be confused with the separate 10% law for transfer from one trophic level to the next.

Result

Therefore, the blank is filled by 1%.