Bacterial geneticsDownloads

A codon is an mRNA sequence consisting of 3 nucleotides that codes for an amino acid. Each position can be made up of any 4 nucleotides (A, U, G, C); therefore, there are a total of 64 (4 x 4 x 4) different codons that can be created but they only code for 20 amino acids. This is explained by the wobble phenomenon. One codon for leucine is CUU, which of the following can be another codon coding for leucine?

An investigator inoculates three different broths with one colony-forming unit of Escherichia coli. Broth A contains 100 μmol of lactose, broth B contains 100 μmol of glucose, and broth C contains both 100 μmol of lactose and 100 μmol of glucose. After 24 hours, the amounts of lactose, galactose, and glucose in the three broths are measured. The results of the experiment are shown: Lactose Galactose Glucose Broth A 43 μmol 11 μmol 9 μmol Broth B 0 μmol 0 μmol 39 μmol Broth C 94 μmol 1 μmol 66 μmol The observed results are most likely due to which of the following properties of broth A compared to broth C?