You have just transformed 1 ul (100 pg/ul) of control pWasabi (plasmid) DNA into 50 ul of E. coli DH50a by the heat-shock method. You then add 950 µl of SOC medium to outgrow the bacteria. Of this, you plated 50 µl onto a LB plate containing ampicillin. After overnight incubation, you observed that there are 150 colony forming units (cfu) on the plate. Calculate the transformation efficiency (show your step-wise calculations below).

You co-culture the following bacterial strains: an Hfr prototroph and an F- auxotroph for the genes mal, met, mtl, and xyl. You interrupt conjugation at various time points and place the mixtures on media plates lacking each of the nutrients. Based on the results shown in the image, what is the order of these four genes along the bacterial chromosome? Please explain!

You are given two samples of DNA, one from Clostridium perfringens and the other from Mycobacterium tuberculosis. Unfortunately, the labels on the tubes of DNA were accidentally removed, and you do not know which DNA sample belongs to which organism. As you were doing some work with Escherichia coli in the lab, you also have some of its DNA available as well. The %G + %C values for each of the organisms is known (C. perfringens, 27%; M. tuberculosis, 67%; E. coli, 50%). Based upon this information, how could you quickly determine the source of the DNA for your two samples?

You are setting up a restriction digest of pUC19. The DNA concentration is 76.4ng/ul. You want to cut with Ndel and Kasl. How would you set up this reaction?

A high cell density culture of recombinant E. coli was carried out according to the following strategy:-Step 1: single batch with exponential growth until 98% conversion of the substrate, starting from V0= 4.0 L, S0=50 g/L/ X0= 1.0 g/LStep 2: batch fed with exponential flow (SF-800 g/L, μ= 0.1 h-1) until reaching X= 50.9 g/L;Step 3: batch fed with constant flow (F= 0.1 L/h) for 4 hours (induction phase with IPTG)Note: consider that the quasi-steady state is reached in both fed-batch stages.Extra data: YX/S = 0.4 gx/gs; μmax= 0.25 h-1; Ks== 1.0 g/L a) What was the cell concentration reached at the end of step 1?b) For step 3, considering that the substrate concentration in the feed was 1/4 of that used in step 2, what was the concentration of cells reached at the end of step 3?C) In terms of cell productivity, which of the three phases of cultivation was the most productive?

Below is shown a plasmid map from a recombinant DNA experiment you have performed. You inserted your gene of interest (labeled gene on the map) into the lac Z reporter gene via a Hind III site. If you digested this recombinant DNA with HindIII what is the size of the DNA fragment(s) you would obtain on a DNA gel electrophoresis? The plasmid alone is 4000 bp. I have attached the image below.

Some bacteria may have higher mutation rates than others follow­ing exposure to UV light. Discuss a reason why this might be the case. What experiments could you do to determine whether this is a likely possibility?

By conducting conjugation experiments between Hfr and recipientstrains, Wollman and Jacob mapped the order of many bacterialgenes. Throughout the course of their studies, they identified severaldifferent Hfr strains in which the F-factor DNA had been integratedat different places along the bacterial chromosome. A sample of theirexperimental results is shown in the following table:Explain how these results are consistent with the idea that thebacterial chromosome is circular?

Why do we use an Electron Scanning Microscope to see bacteriophages over other microscopes?

You are studying a type of bacteria isolated from the acidic water runoff of a mining operation. You subject two batches of the same bacteria type to different environmental growth conditions. One batch is grown at pH 2, while the other is grown at pH 7. All other environmental parameters are kept identical between the two batches. You then collect their proteins and run a Western blot using an antibody that binds to a proton efflux pump protein (which actively expends energy to pump protons out of a cell). How would you characterize the information obtained in this experiment? What does it tell you, and why is that potentially valuable information?