Which is not a structural aspect of ecosystem?

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

Given below is a list of autotrophs and heterotrophs. With your knowledge about food chain, establish various linkages between the organisms on the principle of ‘eating and being eaten’. What is this inter-linkage established known as ?

Algae, hydrilla, grasshopper, rat, squirrel, crow, maize plant, deer, rabbit, lizard, wolf, snake, peacock, phytoplankton, crustaceans, whale, tiger, lion, sparrow, duck, crane, cockroach, spider, toad, fish, leopard, elephant, goat, nymphae, spirogyra.

The planktonic forms are

In a food chain of grassland ecosystem, the top consumers are

Identify the likely organisms $(1), (2), (3)$ and $(4)$ in the food web shown below.