Which of the following are the essential sources for releasing in the atmosphere?
$I.$ Burning of wood
$II.$ Volcanic activity
$III.$ Combustion of organic matter
$IV.$ Fossil fuels
Choose the correct option
$I, II \;and\; III$
$II, III \;and \;IV$
$I, III\; and\; IV$
$I, II, III\; and\; IV$
Which of the following supports a dense population of plankton and littoral vegetation
The green plants are removed from an aquarium
If plant (producers) of an ecosystem die, then the system
Name any two organisms which can occupy more than one trophic level in an ecosystem.
Primary producer of an ecosystem is