Study the biological mechanism/functioning of a VIRUS and what measures/
precautions you can take.
Answers
Answer:
Even though the angiosperms show such a large diversity in external structure or morphology, they are all characterised by presence of roots, stems, leaves, flowers and fruits. ... The underground part of the flowering plant is the root system while the portion above the ground forms the shoot system
Explanation:
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methods for growing, purifying, counting, and characterizing viruses. It also provides general principles of diagnostic virology. As obligate intracellular parasites, viruses require cell in which to replicate. The cells must express appropriate receptors and other proteins required by the virus. Cultured cells are often used to study basic steps in virus replication. Viruses can be purified away from cellular proteins and organelles using centrifugation techniques. Most viruses cannot be seen using standard light microscopes, but are often imaged using electron microscopy. Methods that combine image collection and computationally demanding image processing can provide incredible details about virus architecture. Another common way to visualize viruses is to use fluorescent tags or dyes. Although these techniques do not show detailed virus structures, they can be used to follow the progress of a virus through a cell and can provide a direct window into protein–protein interactions required for virus replication. A more indirect method to detect viruses is to look for virally induced changes to cell morphology. A variety of basic biochemical techniques are useful for analyzing viral proteins and nucleic acids. As the viral genomes are relatively simple, they can be manipulated/mutated to study the function of virtually any viral protein. Powerful genetic techniques can also be used to generate “designer” cells or organisms. There are a variety of methods for quantitating viruses. Infectivity assays measure the ability of a virus to productively infect a cell. Techniques that identify specific viral proteins or genomes provide ways to rapidly identify viruses. Some of these assays can be used at the bedside, or in the field. Powerful and inexpensive DNA sequencing technologies are being used to identify new viruses, many of which could not be found by other methods. The challenge is to understand how or if these viruses impact their hosts. methods for growing, purifying, counting, and characterizing viruses. It also presents general principles of diagnostic virology. After studying this chapter, you should be able to:
• Describe general requirements for culturing cells and tissues.
• Describe differences between cultures of primary and transformed cells.
• Describe how centrifugation is used to purify viruses.
• Understand the types of information provided by negative staining electron microscopy (EM), thin sectioning EM, cryo-EM, and confocal microscopy.
• Understand what is being measured by each of the following techniques: plaque assays, PCR, ELISA, hemagglutination, and hemagglutination inhibition assays.Viruses replicate only within living cells, thus many early studies of viruses were done in bacteria or plants. Tobacco mosaic virus (TMV) was an early “model virus” as it replicates in a variety of plants, at levels sufficient for biochemical analysis and imaging. Growing TMV is as simple as applying virus to abraded leaves of a susceptible plant. The earliest studies of animal viruses were limited to using whole animals. When possible animal pathogens were adapted to small animals such as mice, rats, and rabbits. These small animal models provided a means to study viral pathogenesis and vaccine efficacy. Fertile chicken and duck eggs were, and continue to be, widely used for propagating viruses. In the 1940s and 1950s development of robust cell culture techniques revolutionized the study of animal viruses. Today, most animal viruses are grown in cultured cells.