Theory of inheritance of acquired characters was putforth by

How Biological evolution has taken place ?
 

Branching descent is one of the key concepts of

Write short note on Lamarckism.
 

$I.$ Use and disuse of organs

$II.$ Inheritance of acquired characters

$III.$ Branching descent

$IV.$ Natural selection

$V.$ Mutation

$VI.$ Reproductive isolation

The two key concepts of Darwinism from the given options are