Bacterial systems serve as an excellent model to express proteins but has a disadvantage – what is that disadvantage?

We isolate DNA from a bacteria that is wild type for the genes arg leu and his shear it in a blender mix it into a culture of bacteria that is mutant for the genes arg leu and his . We then plate on various media. These are the results: Media with arginine 20 colonies /ml Media with histidine 300 colonies /ml Media with leucine 500 colonies /ml Media with all three 10000 colonies/ml 21. What is this experiment called? A. transpiration B. conjugation C. transformation D. transduction

In transformation, a bacterial cell takes up DNA fragments from its surroundings. The figure shows the process of natural transformation. Position the labels below with the correct images. (A) Donor and recipient genomes The donor strand is integrated into the recipient chromosome and the displaced bacterial DNA is degraded. A wild-type donor cell is in the vicinity of a double auxotroph. If the wild-type cell lyses, it releases DNA into the environment. One cell is identical to the original recipient, while the other carries the wild-type genes. A competent recipient cells a receptor site on its surface. One strand of donor DNA enters the cell and pairs with a homologous region of the bacterial chromosome The remaining DNA strand is degraded. A donor DNA strand binds to the receptor site. Reset trpC1 Wild-type donor cell Mechanism of natural transformation Donor DNA hal Receptor site- trpc/his double auxotroph Recipient cell Competent cell recipient -Bacterial chromosome (had.bpC") Ma…

Restriction endonucleases are bacterial enzymes that cleave duplex (double-stranded) DNA at specific nucleotide sequences. The mode of replication of the animal virus SV40 has been investigated by using restriction endonucleases that cleave SV40 DNA into a number of unique segments. Like most viruses, SV40 DNA is circular. The map positions of the 11 fragments produced by a pair of restriction endonucleases are shown on the next page. Immediately following a 5 or 10 minute pulse of radioactively labeled thymidine, labeled SV40 molecules that have completed replication during the pulse are isolated. These newly replicated DNA molecules are digested by the restriction endonucleases and the resulting fragments are analyzed for the relative amounts of pulse label they contain. The results are in the table below. Assume that at the time the label was added there was a random population of replicating SV40 DNA molecules in all possible stages of synthesis. From the information given below,…