Zoology - Molecular Basis of Inheritance Question with Solution | TestHub
E.coli cells with a mustard gene of the lac operon cannot grow in medium containing only lactose as the source of energy because:NEET 2005
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The gene in the lac operon encodes for a galactosidase protein. This protein is an enzyme that is capable of breaking down the lactose into simpler sugars which can be absorbed by the bacteria. Hence a mutated gene would result in a non-functional enzyme and thus the bacteria cannot grow. Related Theory Glucose is the preferred and most frequently available energy source for E. coli. The enzymes to metabolize glucose are made constantly by E. coli. When E. coli is exposed to both lactose and glucose, the organism first metabolise glucose and then temporarily cease to grow until the genes of lac operon become included to provide the ability to metabolise lactose.
