In your research on gene regulation in E. coli, you produce 2 mutant strains with the same phenotype: they can grow on lactose but not on glucose. To investigate these 2 mutants further, you perform a complementation test using them and discover that the diploid combination strain can grow on glucose or lactose. From this, you can deduce that:. A) Both mutants have a mutation in the same gene
B) The 2 mutants have mutations in different genes
C) Glucose and lactose metabolic pathways in E. coli utilize at least one shared gene in common
D) At least 2 different genes are required for glucose metabolism in E. coli
E) B and D.

E) B and D.

Explanation:

A test that is used to  determine if two mutations that are associated with a specific phenotype are allelic or non allelic is known as a complementation test. If the mutation is allelic then the combination does not complement, but if complementation occurs it shows that the combination is not allelic.In the given case, the mutants cannot grow on glucose, however a combination of two strains were able to grow on glucose, this means they are able to complement each other.If they complement each other this means that mutations lie on different genes and since, they are affecting the growth on glucose it also confirms that the atleast 2 different genes are required for glucose metabolism in E.coli.

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