The annual net primary productivity of the biosphere is about:
- 550 billion tons
- 770 billion tons
- 170 billion tons
- 270 billion tons
Show answer and solution
Correct answer: C. 170 billion tons
1. The figure is given as dry weight of organic matter.
2. Oceans contribute only 55 billion tons of it.
3. The total is approximately 170 billion tons.
4. So the answer is 170 billion tons.
_Source: syllabus Biology, Ch 12 'Ecosystem'_