Ans. All living beings start ageing from the moment they are born. The best part with the process of growing old is that we are able to witness many changes. India is one of the most populous nations in the world. In India we have more of youth population than old people.

It increases the productivity and earning capacity in the society. We can guess the age of a tree by counting the rings in its trunk. The age of rock and horse can be identified by carbon dating process. Microorganisms have the shortest life cycle.

Insects too live a short life. Animals like elephant and tortoise live more than 100 years. Life expectancy of human is around 85 years.