What is true about the phosphorus cycle?
$I.$ Rocks are the natural reservoirs of phosphorus
$II.$ Weathering of sedimentary rocks makes phosphate available to the soil
$III.$ Herbivores and carnivores obtain phosphorus from plant directly or indirectly Choose the correct option
$I \;and\; II$
$I \;and \;III$
$II \;and \;III$
$I, II \;and\; III$
Assertion : Net primary productivity is gross primary productivity minus respiration.
Reason : Secondary productivity is produced by heterotrophs
Amount of inorganic substances present in an ecosystem is ______. Energy flow is a ______ feature of ecosystem.
Gaseous type of nutrient cycles are .......
Biome is
Tropical rain forests are found in