NATURE AND DEVELOPMENT OF VIRUSES The Nature of Viruses Viruses are sub-cellular agents of infection that must utilize the cellular machinery of bacteria‚ plants or animals in order to reproduce. Composed of a single strand of genetic material (DNA or RNA) encased in a protein capsid‚ a virus is too small to be seen by standard light microscopy; indeed‚ most are less than one hundredth the size of a bacterium. Specific proteins on the viral capsid attach to receptors on the host cell; this
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VIRUSES Viruses are not classified in any kingdom yet because they are not really alive. They only show signs of life after they infect a host cell. Virus: lifeless particle that does not carry out any METABOLIC functions on its own and CANNOT REPRODUCE on its own until it invades a living HOST cell Viral history: Viral history is relatively short. It begins with the isolation of the human influenza virus in the 1930s and crystallization of the tobacco mosaic virus in 1933‚ and moves through
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Isolation and identification of pathogenic bacteria associated with frozen mackerel fish (Scomber scombrus) in a humid tropical environment Eze‚ E. I. 1 ‚ Echezona‚ B. C. 1 * and Uzodinma‚ E. C. 2 1 Department of Crop Science‚ University of Nigeria‚ Nsukka‚ Nigeria. 2 Department of Science Laboratory Technology‚ University of Nigeria‚ Nsukka‚ Nigeria. Accepted 8 January‚ 2010 Aquaculture products can harbour pathogenic bacteria which are part of the natural micro-flora of the environment. An in-vitro
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TAQ1 Definition of Pathogen and research into the main features of bacteria‚ protozoa‚ fungi and viruses. Pathogens‚ or infectious agents‚ are microorganisms that cause disease or illness to their host. There are divided into four groups; bacteria‚ protozoa‚ fungi and viruses. The term pathogen most often describes an organism that disrupts the normal physiology of a plant or animal. In identifying a pathogen it is important to determine the properties that ‘contribute to its infectious
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BACTERIA Period: 4 Characteristics: 3 major shapes Cocci Basilli Spirilla 3 major components Mesosomes flagella Plasmids Growing Up: Bacteria can obtain energy through phototrophs(sunlight)‚ lithotrophs(inorganic compounds)‚ and organotrophs(organic compounds) Marriage/Reproduction Binary Fission: The process by which all bacteria reproduce. It results in the separation of a single cell into two. Transformation: genetic alteration
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A. Is a Virus Alive? 1. Viruses are segments of nucleic acids contained in a protein coat. 2. Pathogens are agents that cause disease. 3. Viruses do not grow‚ do not have homeostasis‚ and do not metabolize‚ therefore scientists don’t consider them to be living. 4. Discovery of Viruses i. Scientists filtered bacteria from the sap of infected plants‚ and were surprised to find that the filtered sap could still cause uninfected plants to become infected. ii. In 1935‚ Wendell Stanley of the Rockefeller
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Bacterial Contamination April 15‚ 2013 Bacteria Contamination The definition of bacterial contamination is food contamination refers to foods that are spoiled or tainted because they either contain microorganisms‚ such as bacteria or parasites‚ or toxic substances that make them unfit for consumption This is very serious and people should take more precaution‚ food contamination is a serious because it results in foodborne diseases that each year affect an estimated seventy-six million
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Although computer viruses and biological viruses are not related in any way‚ they are very similar in many aspects. Both viruses need a host to replicate for a means of survival. Similarly‚ both enter their hosts passively. Biological hosts are infected by breathing‚ ingestion‚ or direct contact while infected software‚ email attachments and transfers infect the cyber host. Another notable similarity is the fact that both computer and biological viruses need the proper host as well as software and
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P1: you must explain how infections are caused by‚ bacteria‚ viruses‚ fungi and parasites. P2: you must explain how pathogenic microorganisms grow and spread. In this assignment I am going to explain how infections are caused by‚ bacteria‚ viruses‚ fungi and parasites. I will then explain how pathogenic microorganisms grow and spread. Infection is the process where germs enter a susceptible area in the body‚ where they multiply‚ resulting in disease. Colonisation is where microbes are present
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Virus and Bacteria Virus - A virus is a capsule of protein that contains genetic material. A virus cannot reproduce on its own; it must infect a living cell to grow. Bacteria - Bacteria are one-celled organisms that live on their own. They can multiply and reproduce by subdivision Bacteria and viruses cause many of the diseases we are familiar with and may sound synonymous; they are greatly different from each other. [pic] o They differ greatly in size. The biggest viruses are only as large
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