One living thing is plants. plants depend on animals by giving big or small animals shelter and food. this was one thing out of a million.
This query leads to the Food Chain.You must know that all living organisms depend on plants for survival.Yes,on 'plants' for survival.Even humans.Plants are called the 'producers'.This is because they make their own food through a process called 'photosynthesis'.See,if there are no plants ,then :cows,goats,chickens,sheep,cattle e.t.c.(herbivores) that humans eat,will not be there because :cows eat plants;goats eat plants;chicken eats grains which also comes from plants;sheep eats plants;and all the others ,as you now realise eat plants !!!!!!!!!!!!!!!!!!!!
If there will be no plants,then these animals(which are food )will not exist and if food-(sorry,I meant animals)will not exist,then we,humans will not exist!!And,as for carnivores, (animals that eat the flesh or meat of other animals) they also will not exist because they eat herbivores (animals which eat plants) and if plants will not exist that means :no herbivores,no carnivores and no omnivores (animals that eat plants and animals .Humans are omnivores too.)
Example:1
There is an oak tree standing in a garden.Some leaves have fallen on the ground.There are four caterpillars around.They eat the leaves.There are two robins flying in the sky.They see the four caterpillars and fly down and eat them.The birds are then eaten by a sparrowhawk.Oak tree leaves:four caterpillars:two robins:one sparrowhawk.