The virus is an obligate intracellular parasite which can reproduce only by attacking and taking over host cells as they lack the cellular machinery for reproduction. A viroid is sub viral, smallest agent of infectious disease.
Virus is a particle of nucleoprotein.
The virus has a protein covering around genetic material which is called capsid.
A viroid is an infectious RNA particle.
The nucleic acid of the virus can be DNA or RNA.
The nucleic acid of viroid is the only
Viroid has no protein covering around RNA.
The virus infects all types of cells.
Viroid infects only plant cells.
Virus
Any of various submicroscopic agents that infect living organisms, often causing disease, and that consist of a single or double strand of RNA or DNA surrounded by a protein coat. Unable to replicate without a host cell, viruses are typically not considered living organisms.
Viroid
An infectious particle, similar to but smaller than a virus, that consists solely of a strand of RNA and is capable of causing disease in plants.
Virus
A disease caused by a virus.
Viroid
A short section of RNA but without the protein coat typical of viruses, that are plant pathogens
Virus
A computer program or series of commands that can replicate itself and that spreads by inserting copies of itself into other files or programs which users later transfer to other computers. Viruses usually have a harmful effect, as in erasing all the data on a disk.
Viroid
Certain defective viruses, such as hepatitis D, a human pathogen.
Virus
A harmful or destructive influence
The pernicious virus of racism.
Viroid
The smallest of viruses; a plant virus with its RNA arranged in a circular chromosome without a protein coat
Virus
A submicroscopic, non-cellular structure consisting of a core of DNA or RNA surrounded by a protein coat, that requires a living host cell to replicate, and often causes disease in the host organism; such agents are often classed as nonliving infectious particles and less often as microorganisms.
Virus
(uncountable) A quantity of such infectious agents
Virus
A disease caused by such an infectious agent; a viral illness.
He's got a virus and had to stay home from school.
Virus
(archaic) Venom, as produced by a poisonous animal etc.
Virus
(computing) A type of malware which can covertly transmit itself between computers via networks (especially the Internet) or removable storage such as disks, often causing damage to systems and data; also computer virus.
Virus
Any type of malware.
Virus
(figurative) Any malicious or dangerous entity that spreads from one place or person to another.
Virus
To send or infect an electronic device with a computer virus.
I'm just going to virus anyone who tries cheating on this game.
Virus
Contagious or poisonous matter, as of specific ulcers, the bite of snakes, etc.; - applied to organic poisons.
Virus
The causative agent of a disease, .
Virus
Any of numerous submicroscopic complex organic objects which have genetic material and may be considered as living organisms but have no proper cell membrane, and thus cannot by themselves perform metabolic processes, requiring entry into a host cell in order to multiply. The simplest viruses have no lipid envelope and may be considered as complex aggregates of molecules, sometimes only a nucleic acid (DNA or RNA) and a coat protein. They are sometimes viewed as being on the borderline between living and nonliving objects. They are smaller than living cells in size, usually between 20 and 300 nm; thus they pass through standard filters, and were previously referred to as filterable virus. The manifestations of disease caused by multiplication of viruses in cells may be due to destruction of the cells caused by subversion of the cellular metabolic processes by the virus, or by synthesis of a virus-specific toxin. Viruses may infect animals, plants, or microorganisms; those infecting bacteria are also called bacteriophages. Certain bacteriophages may be non-destructive and benign in the host; - see bacteriophage.
Virus
Fig.: Any morbid corrupting quality in intellectual or moral conditions; something that poisons the mind or the soul; as, the virus of obscene books.
Virus
A program or segment of program code that may make copies of itself (replicate), attach itself to other programs, and perform unwanted actions within a computer; also called computer virus or virus program. Such programs are almost always introduced into a computer without the knowledge or assent of its owner, and are often malicious, causing destructive actions such as erasing data on disk, but sometime only annoying, causing peculiar objects to appear on the display. The form of sociopathic mental disease that causes a programmer to write such a program has not yet been given a name. Compare trojan horse{3}.
Virus
(virology) ultramicroscopic infectious agent that replicates itself only within cells of living hosts; many are pathogenic; a piece of nucleic acid (DNA or RNA) wrapped in a thin coat of protein
Virus
A harmful or corrupting agency;
Bigotry is a virus that must not be allowed to spread
The virus of jealousy is latent in everyone
Virus
A software program capable of reproducing itself and usually capable of causing great harm to files or other programs on the same computer;
A true virus cannot spread to another computer without human assistance
A virus is a small non cellular particle made up of genetic material and protein that can invade living cells. Viruses are non cellular, nonliving structures having a protein coat called capsid and nucleic acid (DNA, RNA) core. Viruses can replicate only inside a host cell. Some viruses are enclosed in a protective envelop. Some viruses have spikes which help in the attachment of host cells. Viral subunits are made of individual protein subunits which are called capsomeres. The study of viruses is called virology. Beijerinck coined the Latin name virus which means poison in 1897. He studied filtered plant juices and found they caused healthy plants to become infectious. Wendell Stanley crystallized sap from diseased tobacco plants in1935. He discovered that viruses are composed of nucleic acids and protein. Edward Jenner developed a small pox vaccine using milder cowpox viruses in 1796. Deadly viruses are said to be virulent. Small pox has eradicated now a days in the world. Viruses are smaller than small cells and measured in nanometer. Viruses could not be seen until electron microscope was discovered in the 20th century. Outside of host cells, viruses are inactive, lack ribosomes and enzymes which are needed for metabolism. Viruses come in a variety of shapes. Some have a helical shape for example Ebola virus. Some have polyhedral shapes like influenza virus, and some have very complex shapes like bacteriophages. Viruses which attack bacteria are called bacteriophages. T-phages are a particular class of bacteriophages with icosahedral heads, double stranded DNA, and tails. The most commonly studied T-phages are T4 and T7. They infect E-coli which is an intestinal bacterium. Six small spikes at the base of tail are used to attach to the host cells. Adsorption, penetration, uncoating, synthesis, assembly, and release are modes of virus replication. Common cold, chickenpox, influence, and cold sores are examples of common human diseases caused by viruses. Many chronic diseases such as AIDS, SARS, avian influenza and Ebola virus disease are also produced by viruses. The relative ability of the virus to cause disease is designated in term of virulence. Other diseases are under examination to discover if they have a virus as the causative agent, such as the likely connection between human herpesvirus 6 and neurological diseases such as multiple sclerosis and chronic fatigue syndrome. Viruses are important to study cell and molecular biology as they provide simple systems that can be used to investigate and manipulate the functions of cells.
Viroids are sub viral, smallest infectious pathogens. They are made up of a short strand of circular, single strand RNA without a protein coat. All viroids are present on higher plants and cause diseases in them. Some are present in infected host cell nucleolus while others are present in chloroplasts. Viroids cause diseases by RNA silencing. Some diseases are slight, but some cause a lot of economic loss. There are 20 viroids which vary in nucleotide sequence. Viroids resemble prions which are cut from eukaryotic cells. Theodor Otto Diener who was a well-known plant pathologist, discovered viroid first time in U.S Department of Agriculture’s research center in Beltsville, Maryland in 1971. He also characterized viroid on a molecular basis and named it. That first viroid was a pathogenic agent of the potato spindle tuber disease. This viroid is called potato spindle tuber viroid (PSTVd) now a days. Viroids are composed of nucleic acid but do not code for any protein. Replication mechanism of viroids uses RNA polymerase II which is a host cell enzyme. The human causative agent, hepatitis D virus, is a defective RNA virus similar to a viroid. Viroid infections are transferred by cross contamination following damage to the plants as a result of horticultural or agricultural practices. Aphids transmit some, and they can also be shifted from the plant by leaf contact.
