| 1. | It occurs only through the process of photosynthesis. | 
| 2. | Almost all life on Earth relies directly or indirectly on primary production. | 
| 3. | Net primary production is available for consumption by herbivores. | 
| 4. | Gross primary productivity minus the respiratory loss is the net primary productivity. | 
| 1. | 25 % of the annual net primary productivity of the whole biosphere | 
| 2. | 33 % of the annual net primary productivity of the whole biosphere | 
| 3. | 66 % of the annual net primary productivity of the whole biosphere | 
| 4. | 70 % of the annual net primary productivity of the whole biosphere | 
| 1. | Primary productivity - Varies in different types of ecosystems | 
| 2. | GPP - Available biomass for the consumption to herbivores | 
| 3. | 55 billion tons - Annual NPP of oceans | 
| 4. | Secondary productivity - Rate of formation of new organic matter by consumers | 
| 1. | GPP is the total rate of photosynthesis, including both organic matter used in respiration and biomass accumulation; NPP is only the biomass accumulation. | 
| 2. | GPP refers to the energy stored by consumers, while NPP refers to the energy stored by producers. | 
| 3. | GPP is the total biomass accumulated, while NPP is the leftover energy after plants' metabolic needs are met. | 
| 4. | NPP is always higher than GPP because it includes consumer productivity. | 
| Statement I: | The annual net primary productivity of the entire biosphere is approximately 170 billion tons of wet fresh weight organic matter. | 
| Statement II: | Oceans contribute the majority of the net primary productivity of the biosphere. | 
| 1. | Both statements I and II are correct | 
| 2. | Both statements I and II are incorrect | 
| 3. | Statement I is correct but Statement II is incorrect | 
| 4. | Statement I is incorrect but Statement II is correct | 
| 1. | Primary production | 2. | Primary productivity | 
| 3. | Secondary production | 4. | Secondary productivity | 
| 1. | Fragmentation → Leaching → Catabolism | 
| 2. | Catabolism → Leaching → Fragmentation | 
| 3. | Leaching → Fragmentation → Catabolism | 
| 4. | There is no sequence as all steps occur simultaneously |