Question

The auxotrophic strain of E. coli that will be used today cannot independently synthesize tryptophan, an amino acid. They possess a __?

1) Plasmid
2) Mutation
3) Deficiency
4) Gene

Answer 1

An auxotrophic strain of E. coli that cannot synthesize tryptophan possesses a mutation in the genes required for its synthesis.

Step-by-step explanation:

The auxotrophic strain of E. coli that cannot independently synthesize tryptophan possesses a mutation. A functional trp operon is required for the synthesis of tryptophan; however, if there is a loss-of-function mutation in any of the genes encoding this pathway, the bacterium loses the ability to produce tryptophan on its own. This type of mutation leads to auxotrophy for tryptophan, making the strain-dependent on external sources of this amino acid. The auxotrophic strain of E. coli that cannot independently synthesize tryptophan possesses a mutation.