Distributional Maps - Isopleth Method

Give reasons why following sentence is right or wrong:

Isopleth maps are used to show population distribution.

Give reasons why following sentence is right or wrong:

Isopleth maps are not made using isolines.

Which method will you use for the following information ?

Distribution of the altitude of the land in the district.

Which method will you use for the following information ?

Temperature distribution in Maharashtra State.

Answer in brief.

Differentiate between choropleth and isopleths methods.