Define the following terms
Planet

Explanation

(a) Migration. Movement of animals from one habitat to another for food, shelter, job or from unfavourable to favourable habitat is called as migration.
(b) Stratosphere. It is the 2nd major layer of the atmosphere, just above the troposphere, below the mesosphere about 18 km above the earth.s surface. It is stratified in temperature, with warmer layers higher and cooler layers closer to earth. The increase of temperature with altitude is a result of the absorption of U.V. radiations by ozone.
(c) Community. An assembly of populations of different species of plants, animals, fungi, bacteria living in a particular area and interact with one another is called as community.
(d) Biosphere. It is biologically inhabited part of earth alongwith its physical environment consisting of lower atmosphere, land and water bodies.