Practice question

Minimal medium deliberately excludes complex nutrients containing only simple carbon source like glucose or sucrose supplying energy, inorganic salts supplying nitrogen, phosphate and sulfate, trace elements and single vitamin biotin for Neurospora. No amino acids, purines or yeast extract added forcing organism to manufacture all macromolecular precursors endogenously via its own enzymes. This selective medium supports prototrophs but reveals auxotrophs through growth failure, enabling screens for nutritional mutants and ordering of biosynthetic steps via supplementation tests after mutagenesis in microbial genetics experiments.