Biology Answer the following questions in detail.

Describe steady population with the help of a pyramid.

Define parasitism and give any 'two' types with suitable example of each.

Describe diagrammatic representation of age structure showing declining population.

The following diagram indicates which type of interaction? Write a note on the same.

Name the interaction in:
(a) Lichen (b)Sucker fish and shark
(c) A protozoan living in the digestive tract of a flea living on a dog.

With the help of suitable diagrams, explain how the age structures determine the trend of population.

With the help of pyramid, describe the growing population.