The amount of nutrients present in the soil, at any given time, is referred to as:
1. Standing state
2. Standing crop
3. Primary productivity
4. Secondary productivity

The nutrients in an ecosystem are:

The reservoir is located in the Earth’s crust for:
I. Gaseous type of nutrient cycle
II. Sedimentary nutrient cycle
1. Only I
2. Only II
3. Both I and II
4. Neither I nor II

The function of a reservoir of nutrient cycle is to:
1. synthesize minerals
2. transfer minerals to other ecosystems
3. meet any deficit
4. destroy the unwanted minerals

The dry weight of living organisms is mainly made up of:

The maximum percent of total global carbon is found:
1. in fossil fuels
2. in atmosphere
3. dissolved in oceans
4. in biomass of microbes

The amount of carbon dioxide in the atmosphere is regulated mainly by:
1. the atmosphere itself
2. human activities
3. decomposition by microbes
4. the oceanic reservoir

Carbon dioxide is returned to the atmosphere by all the following except:
1. photosynthesis by the primary producers
2. respiratory activities of producers and consumers
3. decomposers
4. volcanic activity

Deforestation has affected the carbon cycle primarily by:

Regarding phosphorus cycle:

1. Only I is true.
2. Only II is true.
3. Both I and II are true.
4. Both I and II are false.