1. Compare and Contrast a bacterium and a virus by writing either "Present" or "Absent" for each of the following structures: Structure Cell Membrane Functional Ribosome Cytoplasm Nucleic Acid Nuclear Membrane Bacterium Virus 2. Discuss the similarities and differences between the lytic cycle and the lysogenic cycle. 3. How is a provirus like a prophage? How is it different? 4. What is the difference between an epidemic and a pandemic? 5. What is RNA-dependent RNA polymerase? What is reverse transcriptase? How are they involved in viral infections?
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I need someone to write a detailed summary of the following information. The following information is supposed to be at most 2 paragraphs, but I wrote too much information. A bacteriophage is a virus that infects and replicates within bacteria and archaea. Bacteriophages are composed of proteins that encapsulate a DNA or RNA genome. The structure of bacteriophages varies, meaning that their structure can be complex, or it can even be simple. According to Wikipedia, the same is true for their genomes; their genome can encode as small as four genes to as many as hundreds of genes. Their genomes can also range in size from 3.4 kb up to almost 500 kb; also, phage genomes are highly mosaic, with each unique genome representing a different combination of the same modules that have reshuffled over years of evolution. Bacteriophages were accidentally discovered by Frederick Twort, who was unsuccessfully attempting to propagate the smallpox vaccine's primary component, vaccinia virus, on agar plates. Instead of successfully propagating the vaccinia virus, the plates instead showed spots where the bacteria had lysed. After some research, he concluded that perhaps the cause of these spots was an "ultramicroscopic virus," according to (Keen, 2016), but without the ability to confirm this, he did not continue to research the matter. It was not until two years later, in 1917, that a scientist named Felix d'Herelle found results similar to that of Frederick Twort's, and he coined the phrase bacteriophage as the name of these "tiny microscopic viruses" (Keen, 2016). According to (Keen, 2016) in the article I read, the importance of phages was not realized until the last twenty-five years or so, and it was during that time that scientists have come to the conclusion that phages are also the most abundant organisms on earth. It is theorized that more than likely every strain of bacteria is/can be infected by at least one type of phage. Due to the diversity of phages, they are significant drivers of bacterial evolution for multiple reasons. For example, bacteria must constantly evolve to avoid being killed by phages; thus, phages are a driver for evolution. Another example is that temperate phages can undergo horizontal gene transfer between themselves and the host, therefore directly evolving/altering the host bacteria. However, this can also cause problems when a previously non-harmful or low-risk bacteria is converted into highly virulent pathogens due to horizontal gene transfer. On the other hand, phages can play a beneficial role in humans and other animals by colonizing these organisms' mucosal surfaces and acting as a component of innate immunity by managing or transforming surface bacteria. Another example of when bacteriophages can be beneficial is in the case of lytic phages, which have therapeutic potential because they can be used to kill pathogenic bacteria. In short, this means that bacteriophages' main benefit is that they can be used in creating vaccines and antibiotics.
Sri K.
Bacterial and eukaryotic replication have many similarities. Which of the following is not a true comparison? (1 pt) A. Both form loops with the lagging strand template to accommodate the antiparallel nature of DNA. B. Both incorporate a sliding clamp mechanism in their replication polymerase. C. Both use a single polymerase to synthesize the daughter strands. D. Eukaryotic replication rates are slower than bacterial rates. E. The Okazaki fragments generated in eukaryotes are shorter than those in bacteria. Why is there a problem replicating the ends of linear DNA? (1 pt) A. Leading strand synthesis primed at the replication origin of a linear DNA can't remove and replace the primer. B. Lagging strand synthesis primed at the ends of a linear DNA can't be removed and replaced because there is no 3'-OH available. C. Since replication only initiates at the ends of linear DNA, the priming of each leading strand leaves a primer at the end that cannot be removed. D. Okazaki fragments are generated along both strands but DNA ligase is inhibited by the Tus-Ter complexes at the ends of the DNA. E. Primase cannot copy telomere DNA. What structures solve the end replication problem for linear chromosomes? (1 pt) A. telomerases B. centromeres C. origins of replication D. telomeres E. euchromatin Why does the presence of telomeres protect the ends of linear chromosomes? (1 pt) A. Telomere DNA is resistant to nuclease activity. B. The telomeres represent large "buffer zones" of DNA sequence that do not code for biomolecules. Loss of these sequences is easily tolerated. C. Every time somatic cells replicate, telomerase extends the ends of the chromosomes. D. Specialized telomere-binding proteins prevent loss of DNA during replication. E. None of these choices is correct. Which of the following is true about telomeres and immortality? (1 pt) A. Immortal cell lines lack telomeres. B. Immortal cell lines lack telomerase. C. Reactivation of telomerase in humans will cause them to become immortal. D. Tumor cell lines can be immortal if their telomerase gene is reactivated. E. Immortal cell lines have telomerase activity but cannot form t-loops and don't have protective proteins to prevent recombination repair. Which of the following eukaryotic RNA polymerases is responsible for transcribing nearly all protein-coding genes? (1 pt) A. RNA polymerase I B. RNA polymerase II C. RNA polymerase III D. RNA polymerase IV E. a complex of RNA polymerase II and III
Adi S.
Describe the differences between lytic cycle and lysogenic cycle in virus
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