Maximum absorption of rainfall water is done by

Consider the following statements concerning food chains.
$A.$ Removal of $80\%$ tigers from an area resulted in greatly increased growth of vegetation.
$B.$ Removal of most of the carnivores resulted in an increased population of deers.
$C.$ The length of food chains is generally limited to $3-4$ trophic levels due to energy loss.
$D.$ The length of food chains may vary from $2$ to $8$ trophic levels.
Which two of the above statements are correct?

Which of the following are the essential sources for releasing $CO_{2}$ into the atmosphere?
$I.$ Burning of wood
$II.$ Volcanic activity
$III.$ Combustion of organic matter
$IV.$ Fossil fuels
Choose the correct option.

Amount of inorganic substances present in an ecosystem is . . . . . . Energy flow is a . . . . . . feature of ecosystem.

Secondary producers are

The dynamic system of an ecosystem depends on which of the following?