What is the shape of a virus Quizlet?
May 16, 2019 · Viruses generally come in two forms: rods or spheres. However, bacteriophages (viruses that infect bacteria) have a unique shape, with a geometric head and filamentous tail fibers. No matter the shape, all viruses consist of genetic material ( DNA or RNA) and have an outer protein shell, known as a capsid.
What are the different types of viruses?
Viruses vary in the shape of their capsids, which can be either helical, polyhedral, or complex. A helical capsid forms the shape of tobacco mosaic virus (TMV), a naked helical virus, and Ebola virus, an enveloped helical virus. The capsid is cylindrical or rod shaped, with the genome fitting just inside the length of the capsid.
What are the characteristics of a simple virus?
57.Name different shapes of viruses. Which one is unique to viruses? The shape of a virus depends on its capsid – the shape of the capsid determines the virus shape Polyhedral viruses are composed of multiple faces Helical viruses very curly (ex: Ebola virus) Bacteriophage – …
Which of the following is an example of animal virus?
Viruses are simple entities, lacking an energy-generating system and having very limited biosynthetic capabilities. The smallest viruses have only a few genes; the largest viruses have as many as 200. Genetically, however, viruses have many features in common with cells. Viruses are subject to mutations, the genomes of different viruses can recombine to form novel progeny, …
Which shape is unique to viruses?
Most viruses have icosahedral or helical capsid structure, although a few have complex virion architecture. An icosahedron is a geometric shape with 20 sides, each composed of an equilateral triangle, and icosahedral viruses increase the number of structural units in each face to expand capsid size.
What are the different shapes of viruses?
Shapes of viruses are predominantly of two kinds: rods, or filaments, so called because of the linear array of the nucleic acid and the protein subunits; and spheres, which are actually 20-sided (icosahedral) polygons. Most plant viruses are small and are either filaments or polygons, as are many bacterial viruses.
What are the 3 shapes of viruses?
Virus particles come in a wide range of sizes and shapes. Viruses may also be classified according to the structure of the virus particle, or virion. The three major shapes seen are spherical, filamentous, and complex.
What are the 4 main shapes of viruses?
In general, the shapes of viruses are classified into four groups: filamentous, isometric (or icosahedral), enveloped, and head and tail. Filamentous viruses are long and cylindrical. Many plant viruses are filamentous, including TMV (tobacco mosaic virus).Jan 3, 2021
What are the bacteria shapes?
Individual bacteria can assume one of three basic shapes: spherical (coccus), rodlike (bacillus), or curved (vibrio, spirillum, or spirochete). Considerable variation is seen in the actual shapes of bacteria, and cells can be stretched or compressed in one dimension.
What is a virion vs virus?
Viruses are nucleoproteins. They are non-cellular structures with infectious, genetic material. Virions are capsid encapsulated viruses with DNA or RNA molecules. It has both nucleic acid as well as protein layers.
What are the different classes of viruses?
The seven classes of viruses in the Baltimore Classification System are as follows:Class I: Double stranded DNA (dsDNA) viruses. ... Class II: Single stranded DNA (ssDNA) viruses. ... Class III: Double stranded RNA (dsRNA) viruses. ... Class IV: Single stranded RNA (ssRNA) viruses. ... Class V: Single stranded RNA (ssRNA) viruses.More items...•Feb 26, 2019
What is the name of smallest virus?
The smallest viruses in terms of genome size are single-stranded DNA (ssDNA) viruses. Perhaps the most famous is the bacteriophage Phi-X174 with a genome size of 5386 nucleotides.
What is a spherical virus?
Icosahedral. These viruses appear spherical in shape, but a closer look actually reveals they are icosahedral. The icosahedron is made up of equilateral triangles fused together in a spherical shape. This is the most optimal way of forming a closed shell using identical protein sub-units.
What is the general structure of viruses What are the different components?
The simplest virions consist of two basic components: nucleic acid (single- or double-stranded RNA or DNA) and a protein coat, the capsid, which functions as a shell to protect the viral genome from nucleases and which during infection attaches the virion to specific receptors exposed on the prospective host cell.
What's an example of an enveloped virus?
Enveloped viruses can cause persistent infections and must transfer from host to host. Examples of enveloped viruses include ones that cause notorious diseases in humans, such as COVID-19, Influenza, Hepatitis B and C, and Hemorrhagic Fever (Ebola Virus Disease).Apr 8, 2020
Is tobacco mosaic virus?
Tobacco mosaic virus (TMV) is a positive-sense single-stranded RNA virus species in the genus Tobamovirus that infects a wide range of plants, especially tobacco and other members of the family Solanaceae....Tobacco mosaic virusOrder:MartelliviralesFamily:VirgaviridaeGenus:TobamovirusSpecies:Tobacco mosaic virus8 more rows
What is the shape of a virus?
Viruses generally come in two forms: rods or spheres. However, bacteriophages (viruses that infect bacteria) have a unique shape, with a geometric head and filamentous tail fibers.
Why are viruses important?
Because some viruses incorporate their DNA into host DNA, they can be genetically modified to carry genes that would benefit the host.
How do viruses replicate?
There are two processes used by viruses to replicate: the lytic cycle and lysogenic cycle. Some viruses reproduce using both methods, while others only use the lytic cycle. In the lytic cycle, the virus attaches to the host cell and injects its DNA.
What is the cause of the flu?
For example, the flu is caused by the influenza virus. Typically, viruses cause an immune response in the host, and this kills the virus. However, some viruses are not successfully treated by the immune system, such as human immunodeficiency virus, or HIV. This leads to a more chronic infection that is difficult or impossible to cure;
How does a virus get its DNA?
Each time the host’s cells go through replication, the virus’s DNA gets replicated as well, spreading its genetic information throughout the host without having to lyse the infected cells. In humans, viruses can cause many diseases.
Can antibiotics treat viral infections?
Unlike bacterial infections, antibiotics are ineffective at treating viral infections. Viral infections are best prevented by vaccines, though antiviral drugs can treat some viral infections. Most antiviral drugs work by interfering with viral replication.
What is the definition of parasite?
organism that is home to a parasite. infection. Noun. disease caused by microscopic organisms, such as bacteria. influenza. Noun. contagious disease, characterized by fever, exhaustion, and difficulty breathing.
What is the envelope of a virus?
Envelope - Many types of virus have a glycoprotein envelope surrounding the nucleocapsid. The envelope is composed of two lipid layers interspersed with protein molecules (lipoprotein bilayer) and may contain material from the membrane of a host cell as well as that of viral origin.
What are viruses made of?
All viruses contain nucleic acid, either DNA or RNA (but not both), and a protein coat, which encases the nucleic acid. Some viruses are also enclosed by an envelope of fat and protein molecules.
What is the particle of a virus called?
In its infective form, outside the cell, a virus particle is called a virion. Each virion contains at least one unique protein synthesized by specific genes in its nucleic acid. Viroids (meaning "viruslike") are disease-causing organisms that contain only nucleic acid and have no structural proteins.
Can bronchitis cause pneumonia?
A number of complications, such as the onset of bronchitis and pneumonia, can also occur in association with influenza and are especially common among the elderly, young children, and anyone with a suppressed immune system.
Is a virus a living organism?
Viruses are not plants, animals, or bacteria, but they are the quintessential parasites of the living kingdoms. Although they may seem like living organisms because of their prodigious reproductive abilities, viruses are not living organisms in the strict sense of the word. Without a host cell, viruses cannot carry out their life-sustaining ...
What are the properties of viruses?
Properties of Viruses. They are non-cellular organisms, which is enclosed in a protective envelope. The presence of spikes helps in attaching the viruses to the host cell. These viruses do not grow, neither respire nor metabolize, but they reproduce.
What is the name of the virus that infects insects?
Insect virus. The virus which infects insects is known as Insect virus, also called the viral pathogen of insects. These viruses are considered as a powerful biocontrol agent in the landscape of modern agriculture. Ascovirus virions and Entomopox virus, are best examples for insect virus.
What is the function of a virus?
The main task of the virus is to carry its DNA or RNA genome to the host cell, which then can be transcribed by the host cell. The viral genome is packed in a capsulated symmetric protein.
How big are viruses?
Viruses are tiny and smaller in its size, ranging between 30-50 nm. They usually lack a cell wall but are surrounded by a protective protein coating called the capsid. It can be seen as a genetic element and is characterized by the combined evolution of the virus and the host.
Who coined the term "virus"?
The term virus was coined by the Dutch microbiologist, Martinus Willem Beijerinck in the year 1897. It is derived from Latin, which means poison or venomous substance. Once a susceptible cell is infected, a virus can start the cell machinery to generate more virus.
What is the viral genome?
The viral genome is packed in a capsulated symmetric protein. The protein associated with nucleic acid (also known as nucleoprotein) produces the nucleocapsid with the genome. Explore: Difference Between Virus And Bacteria.
Can you see a virus with an electron microscope?
Therefore, they can only be seen with an electron microscope. Many viruses have either DNA or RNA as the genetic element and the nucleic acid with single or double strands. The whole infectious virus, called as virion has nucleic acid and an outer shell of proteins.
How to describe a virus?
By the end of this section, you will be able to: 1 Describe the general characteristics of viruses as pathogens 2 Describe viral genomes 3 Describe the general characteristics of viral life cycles 4 Differentiate among bacteriophages, plant viruses, and animal viruses 5 Describe the characteristics used to identify viruses as obligate intracellular parasites
What are viruses made of?
There are two categories of viruses based on general composition. Viruses formed from only a nucleic acid and capsid are called naked viruses or nonenveloped viruses. Viruses formed with a nucleic-acid packed capsid surrounded by a lipid layer are called enveloped viruses (see Figure 6.5 ).
What type of cell can a virus infect?
Viruses can infect every type of host cell, including those of plants, animals, fungi, protists, bacteria, and archaea. Most viruses will only be able to infect the cells of one or a few species of organism. This is called the host range. However, having a wide host range is not common and viruses will typically only infect specific hosts and only specific cell types within those hosts. The viruses that infect bacteria are called bacteriophages, or simply phages. The word phage comes from the Greek word for devour. Other viruses are just identified by their host group, such as animal or plant viruses. Once a cell is infected, the effects of the virus can vary depending on the type of virus. Viruses may cause abnormal growth of the cell or cell death, alter the cell’s genome, or cause little noticeable effect in the cell.
How do viruses make new particles?
The genome of a virus enters a host cell and directs the production of the viral components, proteins and nucleic acids, needed to form new virus particles called virions. New virions are made in the host cell by assembly of viral components.
What is the name of the virus that infects a host?
The viruses that infect bacteria are called bacteriophages, or simply phages. The word phage comes from the Greek word for devour.
How do viruses affect the cell?
Viruses may cause abnormal growth of the cell or cell death, alter the cell’s genome, or cause little noticeable effect in the cell. Viruses can be transmitted through direct contact, indirect contact with fomites, or through a vector: an animal that transmits a pathogen from one host to another.
How many people are infected with drug resistant bacteria in the US annually?
According to a 2013 report by the US Centers for Disease Control and Prevention (CDC), more than 2 million people are infected with drug-resistant bacteria in the US annually, resulting in at least 23,000 deaths. 3 The continued use and overuse of antibiotics will likely lead to the evolution of even more drug-resistant strains.
What are the different types of influenza?
There are three different types of influenza virus – A, B, and C. Type A viruses infect humans and several types of animals, including birds, pigs, and horses. Type B influenza is normally found only in humans, and type C is mostly found in humans, but has also been found in pigs and dogs.
How does the influenza virus change?
Influenza virus is one of the most changeable viruses known. There are two ways that influenza virus changes – these are called drift and shift. Drifting, or antigenic drift, is a gradual, continuous change that occurs when the virus makes small “mistakes” when copying its genetic information.
How does the flu spread?
Flu, or influenza, is a contagious respiratory illness that spreads from person to person through the air via coughs or sneezes or through contact with infected surfaces. It is caused by a group of continuously changing viruses called influenza viruses.
What antiviral was used in 2009?
Fortunately, the 2009 H1N1 flu was sensitive to two antiviral drugs used to treat influenza - Tamiflu® (oseltamivir) and Relenza® (zanamivir). The drugs act by inhibiting the essential neuraminidase protein (the “N” protein in the naming system).
Can birds get the avian flu?
The virus is very contagious, however, and it can become a problem when the virus is transmitted to domesticated birds, such as chickens, ducks, or turkeys, because domesticated poultry can succumb to illness and death from influenza. Humans generally do not become infected with avian flu.
What is the MVM?
Investigators in the Department of Molecular Virology and Microbiology (MVM) have been studying influenza for several decades, with an Influenza Research Center first established in 1974. A major focus of the work is directed towards the development and testing of influenza vaccines to find the most effective vaccination dosages, methods, and strategies to protect the population against this deadly disease. Other projects involve studying the structure and function of important influenza proteins.
What is the NS1 protein?
Dr. Andrew Rice and colleagues are studying an avian influenza virus protein called NS1 that has recently been shown to be associated with virulence. Proteins like NS1 that are involved in pathogenesis are important targets for novel antiviral therapeutics. The goal of this project is to identify cellular proteins that interact with NS1 and play a role in the pathogenesis of avian influenza virus infection. A critical feature of the avian NS1 protein is the presence of a protein domain at one end of the protein - the carboxyl terminus – that is termed the PDZ-Binding Motif, or PBM. The PBM is predicted to associate with a class of cellular proteins - termed PDZ proteins - that are typically involved in cell-cell contact, cellular polarity, and signaling pathways. It is notable that the NS1 protein of the virulent influenza viruses, such as H5N1, contains a PBM with the sequence ESEV, while other less virulent influenza viruses contain a different PBM sequence or lack this region entirely.
What is a virus made of?
A. Explanation: A virus that is made up of a DNA or RNA genome inside a protein shell is known as a capsid. Some viruses have an external membrane envelope. These are a few questions related to viruses, types, structure, classification, etc. 15 Unknown facts about Viruses.
Why are viruses dependent on their host?
Ans. D. Explanation: Viruses do not contain ribosomes, so they cannot make proteins. That is why they are dependent on their host. Viruses have different shapes, sizes and can be categorised by their shapes. Coronavirus: Origin, Symptoms, Types and Infected countries.
Can viruses be fatal?
Viruses can infect animals, plants, fungi, and bacteria. The virus sometimes can cause a disease that may be fatal. Some virus may also have one effect on one type of organism, but a different effect on another. Viruses cannot replicate without a host so they are classified as parasitic.
Types of Viruses and How They Work
Over many centuries and even millennia, infectious diseases such as smallpox and measles have claimed millions of lives. Advances in modern medicine have helped to stop the spread of many viral infections through mass vaccination, and some infections have been completely eradicated.
Treatment and Prevention
- When an individual is infected with a virus, the body’s immune system goes to war fighting off the intruder. Vaccines can help strengthen the body’s natural immune response and reduce the risk of death.
The Role of Advanced Practice Nurses Worldwide
- Around the world, nurses contribute to the prevention, management and containment of viral outbreaks by caring for infected patients and educating the public on prevention strategies. Advanced practice nurses also fill a leadership role that involves working with government leaders and advocating for health care equality.
The Invaluable Contribution of Nurses
- Across a variety of roles and specializations, nursing professionals fight viruses in numerous ways. Some of their methods are direct, such as preventing surgical infections. Others are legislative in nature, such as advocating for care equality by questioning imbalanced care delivery systems. Nurses also share their expertise with the public on a host of vital topics, such as care …
Definition
Viruses are not plants, animals, or bacteria, but they are the quintessential parasites of the living kingdoms. Although they may seem like living organisms because of their prodigious reproductive abilities, viruses are not living organisms in the strict sense of the word.
Life cycle
- Without a host cell, viruses cannot carry out their life-sustaining functions or reproduce. They cannot synthesize proteins, because they lack ribosomes and must use the ribosomes of their host cells to translate viral messenger RNA into viral proteins. Viruses cannot generate or store energy in the form of adenosine triphosphate (ATP), but have to derive their energy, and all othe…
Structure
- All viruses contain nucleic acid, either DNA or RNA (but not both), and a protein coat, which encases the nucleic acid. Some viruses are also enclosed by an envelope of fat and protein molecules. In its infective form, outside the cell, a virus particle is called a virion. Each virion contains at least one unique protein synthesized by specific genes in its nucleic acid. Viroids (m…
Classification
- Viruses are generally classified by the organisms they infect, animals, plants, or bacteria. Since viruses cannot penetrate plant cell walls, virtually all plant viruses are transmitted by insects or other organisms that feed on plants. Certain bacterial viruses, such as the T4 bacteriophage, have evolved an elaborate process of infection. The virus has a \"tail\" which it attaches to the bacteri…
Morphology
- There are predominantly two kinds of shapes found amongst viruses: rods, or filaments, and spheres. The rod shape is due to the linear array of the nucleic acid and the protein subunits making up the capsid. The sphere shape is actually a 20-sided polygon (icosahedron).
Discovery
- The nature of viruses wasn't understood until the twentieth century, but their effects had been observed for centuries. British physician Edward Jenner even discovered the principle of inoculation in the late eighteenth century, after he observed that people who contracted the mild cowpox disease were generally immune to the deadlier smallpox disease. By the late nineteenth …
Signs and symptoms
- The Influenza (Flu) Virus - Next to the common cold, influenza or \"the flu\" is perhaps the most familiar respiratory infection in the world. In the United States alone, approximately 25 to 50 million people contract influenza each year. The symptoms of the flu are similar to those of the common cold, but tend to be more severe. Fever, headache, fatigue, muscle weakness and pain, …
Introduction
- The Human Immunodeficiency Virus (HIV) - The virus responsible for HIV was first isolated in 1983 by Robert Gallo of the United States and French scientist Luc Montagnier. Since that time, a tremendous amount of research focusing upon the causative agent of AIDS has been carried out and much has been learned about the structure of the virus and its typical course of action. HIV i…
Recommended Video
Also Read: Cytopathic Effect Viruses are tiny and smaller in its size, ranging between 30-50 nm. They usually lack a cell wall but are surrounded by a protective protein coating called the capsid. It can be seen as a genetic element and is characterized by the combined evolution of the virus and the host. They contain ei…
Bacteriophage and HIV
- These microbes belong to the family viridae and genus virus. Viruses could not be placed in any of the kingdoms because they are practically neither living nor dead. The term virus was coined by the Dutch microbiologist, Martinus Willem Beijerinck in the year 1897. It is derived from Latin, which means poison or venomous substance. Once a susceptible cell is infected, a virus can sta…
Classification Based on The Presence of Nucleic Acid
- DNA virus
The virus, having DNA as its genetic material. There are two different types of DNA virus Single-stranded (ss) DNA virus: e.g. Picornaviruses, Parvovirus, etc. Double-stranded (ds) DNA virus: e.g. Adenovirus, Herpes virus, etc. - RNA virus
The virus, having RNA as its genetic material. There are two different types of RNA virus Double-stranded (ds) RNA virus: e.g. Reovirus, etc. Single-stranded (ss) RNA virus. It is further classified into two Positive sense RNA (+RNA) and negative sense RNA (-RNA). Poliovirus, Hepatitis A, Rab…
Classification Based on The Structure Or Symmetry
- Complex virus. E.g Poxvirus
- Radial symmetry virus. E.g.Bacteriophage
- Cubical or icosahedral symmetry shaped virus. E.g. Reovirus, Picornavirus
- Rod or Spiral shaped or helical symmetry virus.E.g. Paramyxovirus, orthomyxovirus
Classification Based on The Replication Properties and Site of Replication
- Here, viruses invade into the host cell, where it replicates and assembly within the cell organelles. 1. Replication within the cytoplasm of the host cell. E.g. All RNA viruses except the Influenza virus. 2. Replication within the nucleus and the cytoplasm of the host cell. E.g. Influenza virus, Poxvirus, etc. 3. Replication within the nucleus of the host cell. All DNA viruses except Pox virus. 4. Replic…
Classification Based on The Mode of Transmission
- Airborne infections – Transmission of the virus through the air into the respiratory tract. E.g. Swine flu, and Rhinovirus.
- Fecal oral route – Transmission of the virus through the contaminated water or food. E.g. Hepatitis A virus, Poliovirus, Rotavirus.
- Sexually transmitted diseases – Transmission of the virus through sexual contacts with the i…
- Airborne infections – Transmission of the virus through the air into the respiratory tract. E.g. Swine flu, and Rhinovirus.
- Fecal oral route – Transmission of the virus through the contaminated water or food. E.g. Hepatitis A virus, Poliovirus, Rotavirus.
- Sexually transmitted diseases – Transmission of the virus through sexual contacts with the infected person. E.g. Retrovirus, human papillomavirus, etc.
- Transfusion-transmitted infections- Transmission of the virus through the blood transfusion. E.g. Hepatitis B virus, Human Immunodeficiency Virus, etc.
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