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Transcription is performed primarily by what enzyme?

The enzyme responsible for relieving stress on the double helix upstream from the replication fork is what?

Which of the following molecules carries amino acids to their corresponding codons?

Which of these will deactivate in the presence of the molecule they are named for?

Define nonsense mutation. Then give an example of this type of mutation, both at the DNA and protein level, and explain what effect this mutation would have on the protein’s function.

Which of the following is true of the lagging strand?

The following is a segment of a DNA strand. Identify the mRNA sequence that would result from transcription of this segment. Be sure to label both ends of the strand as well as identify the sequence of the strand. 5′ – AAGTGACCTTGAC – 3′ 3′ – TTCACTGGAACTG – 5′

The following image show a gel at the end of gel electrophoresis. Well 1 was filled with a control, the exact DNA sequence we are looking for. Wells 3 and 5 were filled with DNA extracted from two different samples. Which of these samples does not contain the DNA sequence we are looking for? Choose all that apply.     [Image ID: Gel with 6 wells, 3 used. Well 1 contains control. Well 3 contains Sample 1. Well 5 contains Sample 2. Bars are seen on the gel in 3 areas: top, middle, bottom. Well 1 shows only middle bar, Well 3 shows middle and bottom, Well 5 shows top and bottom.]

Identify the three steps involved in the polymerase chain reaction (PCR) process. Along with listing each step you should also explain what occurs during each step.

Which of the following is an example of a repressible operon?