Let's say you inoculate four agar plates, each containing a different antibiotic (A, B, C, and D), and you add a swab from a lesion taken from a patient. After incubating the plates, you observe that plate A has only a few colonies, while the others all have many colonies. How do you interpret the results? Multiple Choice Bacteria in the patient's sample carry a mutation that makes them resistant to antibiotic A None of these antibiotics are an acceptable choice to use to treat the patient for this bacterial infection Bacteria in the patient's sample are resistant to antibiotic A, but not B, C, and D Bacteria in the patient's sample are susceptible to antibiotic A but not B, C, and D

step 1: initiation

initiation is the beginning of transcription. it occurs when the enzyme rna polymerase binds to a region of a gene called the promoter. this signals the dna to unwind so the enzyme can ‘‘read’’ the bases in one of the dna strands. the enzyme is now ready to make a strand of mrna with a complementary sequence of bases.

step 2: elongation

elongation is the addition of nucleotides to the mrna strand. rna polymerase reads the unwound dna strand and builds the mrna molecule, using complementary base pairs. there is a brief time during this process when the newly formed rna is bound to the unwound dna. during this process, an adenine (a) in the dna binds to an uracil (u) in the rna.

step 3: termination

termination is the ending of transcription, and occurs when rna polymerase crosses a stop (termination) sequence in the gene. the mrna strand is complete, and it detaches from dna.