Question

The Annual Net Primary Productivity on land and ocean respectively are ________ and ________ billion tons.

• A. 170, 107
• B. 115, 55
• C. 55, 115
• D. 107, 170

Hint:

Always read the requested order carefully! The question asks for Land first, then Ocean. Land = 115, Ocean = 55.

Answer 1

The Correct Option is B

Step 1: Understanding the Concept: Net Primary Productivity (NPP) is the available biomass generated by autotrophs (plants and photosynthetic organisms) across the entire biosphere over a year.
Step 2: Key Formula or Approach: Recall the specific statistical figures provided in standard ecological data concerning global productivity distribution.
Step 3: Detailed Explanation: According to NCERT and standard biological data, the annual net primary productivity of the entire global biosphere is approximately 170 billion tons (dry weight) of organic matter.
Despite occupying nearly 70% of the earth's surface, the productivity of the oceans is surprisingly low, contributing only about 55 billion tons.
The rest of the productivity, which is generated on land, is calculated as the total minus the oceanic productivity: $170 - 55 = 115$ billion tons.
The question asks for the values on land and ocean respectively. Therefore, the sequence must be 115 followed by 55.
Step 4: Final Answer: The correct option is (2).