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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differentiate between bacteria‚ fungi and yeast‚ we plant four different microbes in plates under the same environment for one week and compare the growth of the four microbes by macroscopic and microscopic observation. Meanwhile‚ the diversity of bacteria and fungi in humans‚ the environment and wood could be observed. In addition‚ the four substrates are cultured in two media‚ MEA and NA‚ under the same condition. Thus‚ how nutrients affect the growth of bacteria and fungi could be achieved. During
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a living thing? Are viruses alive or not? To figure out this question we first have to know‚ what defines a living thing. According to the online Merriam-Webster Dictionary‚ life is in particular “an organismic state characterized by capacity for metabolism‚ growth‚ reaction to stimuli‚ and reproduction.” For about 100 years‚ scientists have repeatedly changed their mind over what viruses are. First seen as poisons‚ then as life-forms‚ then biological chemicals‚ viruses today are thought of as
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Viruses‚ Viroids‚ and Prions copyright cmassengale 1 Are Viruses Living or Non-living? Viruses are both and neither They have some properties of life but not others For example‚ viruses can be killed‚ even crystallized like table salt However‚ they can’t maintain a constant internal state (homeostasis). copyright cmassengale 2 What are Viruses? A virus is a noncellular particle made up of genetic material and protein that can invade living cells. copyright cmassengale 3 Viral History copyright
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A fungus (/ˈfʌŋɡəs/; plural: fungi[3] or funguses[4]) is a member of a large group of eukaryoticorganisms that includes microorganisms such as yeasts and molds (British English: moulds)‚ as well as the more familiar mushrooms. These organisms are classified as a kingdom‚ Fungi‚ which is separate from plants‚ animals‚ protists and bacteria. One major difference is that fungal cells have cell walls that contain chitin‚ unlike the cell walls of plants and some protists‚ which contain cellulose‚ and
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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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According to Cambridge Advanced Learner Dictionary Third Edition‚ parasite is an organism that lives on or in another living organism and feeds from it. Parasites are organism that could affect human body and gain benefits on it and gives human diseases out of it. Parasites cause a lot of major disease to human‚ and animals. Parasites also carries diseases from animals and transmit it to humans.Parasite was first discovered by Charles Louis Alphonse Laveran‚ a military doctor in France’s Service
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4/3/12 8 Common Types of Computer Viruses Dictionary.com defines a computer virus as “a segment of self-replicating code planted illegally in a computer program‚ often to damage or shut down a system or network (“Virus‚” 2012).” The term virus has become more generic over the years and has come to represent any type of malware‚ or malicious software. There are many types of malware that can be classified as viruses but it is the intention of this paper to examine 8 of the most common types. These
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ferrets‚ sea lions and even‚ under very rare circumstances‚ humans. The parasite is commonly called "heartworm"; however‚ adults often reside in the pulmonary arterial system as well as the heart‚ and a major effect on the health of the animal is a manifestation of damage to the lung vessels and tissues. Occasionally‚ adult heartworms migrate to the right heart and even the great veins in heavy infections. Heartworm infection may result in serious disease for the host‚ with death typically as the
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a medical dictionary‚ foodborne illness is an acute gastrointestinal infection caused by consuming food contaminated with pathogenic‚ bacteria‚ toxins‚ viruses‚ prions or parasites. Such contamination was caused by improper food handling‚ preparation or storage of food. Contacts between food and pests‚ especially flies‚ cockroaches and rodents are a further cause of contamination of food. Foodborne illness can also be caused by adding pesticides or medicine to food or consuming or by accidentally
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