Question

Difference between auxotrophs and prototrophs

Answer 1

An auxotroph is a mutated variety originated from a prototroph.

An auxotrophic mutant cannot synthesis a particular building block, for example an amino acid. As a result the specific amino acid has to be supplied in the medium in order to grow the auxotroph.
Auxotrophs are very important tool for a molecular geneticist, since it gives an idea of the gene coding for a specific enzymes.