Viruses are the smallest known infective agents and perhaps the simplest form of life. The headtail morphology structure is unique to viruses that only infect bacteria and are known as bacteriophages. Influenza a virus is an enveloped virus with a segmented, singlestrand, negativesense rna genome. Describe how viruses were first discovered and how they are detected. Quorum sensing bacteria produce and release chemical signal molecules called autoinducers that increase in concentration as a function. Essentials of medical microbiology apurba sankar sastry. Proteins associate into structural units this is what we see in the electron microscope or when we start to disassociate a capsid, the structural. Classification of viruses is based on morphology, type of nucleic acid, host range, cell specificity, and enzymes carried within the virion. Note in this video i have mistakenly mentioned that viruses are unicellular in nature sorry for that. Download and print this page to make a model of a tmv virus. In light of the above, the present manuscript summarizes the viruses that infect the major fruit trees, including their taxonomy and morphology, and highlights selected viruses.
Abstract abstract quorum sensing is the regulation of gene expression in response to fluctuations in cellpopulation density. Despite the diversity of size and shape of different viruses, the size and shape of any one virus tend to be much more uniform than do the cells of a bacterium. Viruses are infectious particles and they are obligat. Virions, single virus particles, are 20250 nanometers in diameter. Morphology definition of morphology by merriamwebster. The application of these physical techniques combined with the chemical analyses of the viruses revealed the architectural. The head of the virus has an icosahedral shape with a helical shaped tail.
Download s free morphology viruses medical powerpoint template now for your upcoming medical powerpoint presentations. Many viruses have an additional membranous covering enclosing the nucleocapsid. In this article we will discuss about the morphology and replication of influenza virus. The essentials of medical microbiology apurba sankar sastry focuses on providing a good foundation in clinically important concepts and principles of microbiology. Morphology of common viruses stock vector illustration. Helical morphology is seen in nucleocapsids of many filamentous and pleomorphic viruses. Connecting to the internet is one of the short cuts to do.
Free morphology viruses medical powerpoint template for. Lets see morphology and structure of viruses in detail. Learn about the history, types, and features of viruses. Morphology of viruses the chemical constituents described in the previous chapter are found in particles of diverse size and shape in the various viruses isolable from animals, bacteria, plants, and fungi. Virology is the study of viruses, complexes of nucleic acids and proteins that have the capacity for replication in animal, plant and bacterial cells. Virus morphology free download as powerpoint presentation. The knowledge about the structure of virions could be gathered mainly by electron microscopy and xray diffraction studies. The viral parasite causes changes in the cell, particularly its antigenicity. Viruses possess unique infective properties and thus often cause disease in host organisms.
Baylor university college of medicine, houston, texas and lucy rasmussen. There are so many sources that offer and connect us to other world condition. It discusses the description and molecular structures of virus. Structure and classification of viruses medical microbiology ncbi. The chemical constituents described in the previous chapter are found in particles of diverse size and shape in the various viruses isolable from animals, bacteria, plants, and fungi. Although i liked the texture of book too, its pages are not glossy as with other. The family arteriviridae comprises a single genus, arterivirus, which contains all member viruses, and the family roniviridae contains a single genus, okavirus. Some viruses may demonstrate persistent infection in immune compromised hosts.
All virions have a nucleic acid genome covered by a protective layer of proteins, called a capsid. Despite marked differences in their virion morphology, viruses in the families arteriviridae and roniviridae have a similar genome organization and replication strategy. Viruses are grouped on the basis of size and shape, chemical composition and structure of the genome, and mode of replication. Describe the relationship between the viral genome, capsid, and envelope.
Despite the diversity of size and shape of different viruses, the size and shape of anyone virus tend to be much. The virions consist of two basic components, a nucleic acid core which constitutes the viral genome and a surrounding protein shell, known as the capsid. That is, viruses infect specific cells or tissues of specific hosts, or specific bacteria, or specific plants. Microbiology module morphology and classification of bacteria microbiology 2 notes zmost bacteria possess peptidoglycan, a unique polymer that makes its synthesis a good target for antibiotics zprotein synthesis takes place in the cytosol with structurally different ribosomes fig. Introduction to viruses classification, morphology and structure, replication and pathogenicity classification of viruses morphology and structure naked viruses non enveloped replication pathogenicity transmission of viruses virus tissue tropism. This free morphology viruses medical ppt is one of the free medical powerpoint templates available for medical and healthcare professionals on. Viruses are small obligate intracellular parasites, which by definition contain either a rna or dna genome surrounded by a protective, viruscoded protein coat. One of the best thing in book is its language which is very easy to understand. In the past, viruses were classified by the type of nucleic acid they contained, dna or rna, and whether they had single or doublestranded nucleic acid. Viruses were classified as myoviruses, podoviruses, siphoviruses or icosahedral nontailed viruses referred to as nontailed viruses hereafter based on their morphology as defined by the. These include the herpesviruses, human papillomavirus and rubella virus, among.
Because of its minute size, a virus must be studied with the electron microscope. The capsid is made up of protein subunits called capsomeres. Global morphological analysis of marine viruses shows. Some viral capsids are simple polyhedral spheres, whereas others are quite complex in structure. They vary in structure, methods of replication, and the hosts they infect. The size and fine structure of cytomegalovirus was compared with that of herpes virus. Virus is a smallest infectious particle, unicellular, obligate intracellular parasite. Replication of animal viruses attachment, entry, synthesisdna viruses in nucleus of host while capside in the cytoplams, rna viruses in the cytoplasm and act like mrna, maturation nucleus in dna viruses, and cytoplasm in rna viruses, release eveloped bud. The head encloses nucleic acid and acts as the protective covering. Cytomegalovirus stains as a dna virus and is almost identical in size to herpes virus. Describe with suitable diagrams the dna viruses represented by the given models. Protocols for the preparation and imaging of protein aggregates including viruses are provided by.
The bacteriophage uses its tail to attach to the bacterium, creates a hole in the cell wall, and then inserts its dna into the cell using the tail as a channel. Bacteria morphology questions and answers pdf free download in microbiology mcqs,interview questions,objective questions,multiple choice. Microbiologyvirologyimmunologybacteriologyparasitology. A particular focus on studying virus morphology by using singleparticle analysis and xray diffraction may be found in baker and johnson 1997. Ananthanarayan and panikers textbook of microbiology is one of the best books for mbbs second proff students, to develop basic understanding of microbiology. Microscopic morphology and staining of individual bacteria. Morphology of cytomegalovirus salivary gland virus.
Characters of viruses size of viruses shape of viruses structure of viruses it consist of capsid, nucleic acid and envelop. The morphology of colonies on appropriate agar medium. They vary in their structure, their replication methods, and in their target hosts. The virus is much simpler than the bacterial cell, consisting of a core of nucleic acideither deoxyribonucleic acid dna or ribonucleic acid rnaenclosed in a protective membrane of protein called the capsid. Understanding viruses encounters in virology download. Nearly all forms of lifefrom prokaryotic bacteria and. Viral evolution, morphology, and classification biology 2e. Viral specificity refers to the specific kinds of cells a virus can. Viruses come in many shapes and sizes, but these are consistent and distinct for each viral family. Ananthanarayan and panikers textbook of microbiology pdf. It addresses the morphology and classifications of viruses. Simple biochemical characteristics such as the ability to ferment a given carbohydrate.
In this article we will discuss about the morphology and components of virions. Pdf structure and classification of viruses researchgate. A read is counted each time someone views a publication summary such as the title, abstract, and list of authors, clicks on a figure, or views or downloads the fulltext. Free virology books download ebooks online textbooks. Morphology and structure of viruses general microscience. Banana trees, citrus fruit trees, pome fruit trees, grapevines, mango trees, and stone fruit trees are major fruit trees cultured worldwide and correspond to nearly 90% of the global production of woody fruit trees. It is an enveloped virus possessing genome segmented into eight linear single stranded molecules ranging in size from 890 to 2341 nucleotides. Examples include hiv, hepatitis b virus and hepatitis c virus. Virus and bacteria answers pdf following your need to always fulfil the inspiration to obtain everybody is now simple. To replicate themselves, viruses usurp functions of the host cells on which they are parasites. Helical nucleocapsids consist of a helical array of capsid proteins protomers wrapped around a helical filament of. Viruses may cause chronic, persistent infection with continuous viral replication in the face of an immune response. Eukaryote cell difference between prokaryotic and eukaryotic cells. Viruses do not posses cellular organization and they do not fall strictly in to the category of unicellular microorganism.
Viruses are grouped on the basis of size and shape, chemical composition and structure of the genome. Topic wise microbiology questions and answers pdf free. If you need to see the final drawing, here is the one i did on camera. Viruses typically have limited host ranges and infect specific cell types. All phages contain a head structure, which can vary in size and shape. Like other diseases, viral diseases are classified using icd codes. Virus morphology includes the size and shape of the virion, number of capsomers. Viruses may have helical, polyhedral, or complex shapes. To replicate themselves, viruses use up functions of the host cells on which they are parasites. Viruses are infectious particles about 100 times smaller than bacteria and can only be observed by electron microscopy. Morphology of galanthus nivalis or common snowdrop plant with green leaves, white flower, root system and titles green fly sitting isolate on white background rhinovirus rota virus particle structure isolated triangular yellow biohazard sign icon with caution coronavirus biohazard. Its virions show spherical or filamentous shapes of about 100 nm in diameter and occasionally irregular morphology, which exemplifies the pleomorphic nature of these virions. Each viral rna segment forms a ribonucleoprotein complex rnp, along with an rna.
Viral evolution, morphology, and classification biology. Vector diagram year of the rat and virus in china parts of plant. Virus, infectious agent of small size and simple composition that can multiply only in living cells of animals, plants, or bacteria. Learn vocabulary, terms, and more with flashcards, games, and other study tools. Morphology and structure of viruses microbiology with. Virus history, virus diversity, virus shapes, virus sizes, components of genomes, isolation and purification of viruses and components, virus host interaction, positive strand rna virus, negative strand rna viruses, other rna viruses and dna viruses. Some are icosahedral 20 sides others are filamentous.
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