Witch is a biotic factor

The trp operon in e. coli regulates genes that code for enzymes required for synthesis of the repressible operon. when tryptophan is not available amino acid tryptophan. the trp operon is a in the environment, the trp repressor protein activeinactiveregulated. therefore, rna polymerase can bind to the genes to begin transcription.

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The cretaceous period spanned the time interval between and 65 million years ago. 250 million 144 million 75 million 200 million