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Conjugation occurs between cells of the same species too. For this to occur cell have to be close to each other. Now, if you have an isolated population of bacteria that never gets in contact with an F+ bacteria then this population would stay F-. Also not all conjugation events are successful, mechanical perturbations can disrupt the pilus through which ...


4

Short answer. It was discovered pretty early (late 1800's). It is easy to get (you probably know where it comes from), purify, grow and is not virulent. E.coli spreads very rapidly (30 minutes division rate). Why this one in particular and not another similar bacteria? Well you have to choose something at some stage and usually the more an organism is used ...


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Because it is first important to understand a mechanism before you can think about using it for drugs. Take melanoma for example: A large subset of melanoma has a mutated and constitutive active BRAF kinase which permanently signals towards the nucleus and thus deregulates gene expression. Once this mutation was found it was possible to design inhibitors ...


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No, I don't think so. Mostly estuaries (brackish water) and marine biofilms on submerged surfaces are a reservoir for Vibrio cholerae. Vibrio cholerae is isolated from rivers, creeks, washes, irrigation ditches, hulls of ships, etc. (Indeed, cholera spread rapidly throughout the world after the 1817 epidemic, largely due to the inadvertent transport of ...


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The pattern we see in B. subtilis is quite common in prokaryotes. The origin of replication is shown at the top of the genome diagram. DNA replication proceeds bidirectionally from this point. In the B. subtilis diagram, most genes are located along the leading strand in each direction. Even in E. coli, by the way, important genes, including all rRNAs, tend ...


1

Though Escherichia coli has only one origin of replication (oriC), keep in mind that replication proceeds in both directions from it. Thus, based on your calculations, DNA replication takes 40 minutes (which is still too long). The solution is to start replication again before the previous round has completed, and here's some research which shows just that: ...


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Also it is noteworthy that the general idea behind vaccines is to "train" your own immune system to the pathogens. Since we are all different a little bit we produce a little bit different antibodies therefore the pathogens do not have a general counter-strategy or selective pressure compared to antibiotics.


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Unfortunately, we do see examples of bacteria and viruses evolving vaccine resistance. For instance, vaccine resistant strains of polio and pertussis have recently been identified. Yet these seem like the exception rather than the rule. One thing that makes it harder for pathogens to evolve resistance is that vaccines usually generate antibodies to ...


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My society finch love to eat moist grass particularly orchard grass. Nibbling the whole strand they have chosen back and forth until they are satisfied with the texture and then proceeds to swallow it. They brake most grass into no bigger than an inch in length. I buy the orchard grass from most pet stores. problem with that is the grass has been dried. not ...



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