Why are living organisms classified ?

How are living organisms dependent on the soil ? Are organisms that live in water totally independent of soil as a resource ?

A virus can be considered a living organism because it

The high boiling point of water is advantageous to living organisms because

Smallest free living organism is

[A]: The earliest living organisms were structurally simple. [R]: The earliest living organisms were more complex than present one.

A particular species ‘X’ has more characteristics with species 'Y', whereas another species 'Z' has less common characteristics with species 'Y'. Which two species are more closely related? Why? On what basis are the eukaryotic organisms further classified? Why is this basis important? What is the importance of homologous organs?

What are the four ways through which the living organisms respond to abiotic factors?