describe viruses in general terms of their size,and mode of reproduction?
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Viruses are infectious agents that require cells for their reproduction.  The replicate by controlling a living cell’s material independently of the cell’s DNA.  This cell is called a Host.  The viral genetic material can be double stranded DNA, single stranded DNA or RNA.  A virus out side of a living cell is called a virion and is metabolically inert.  (It is also covered by a protein or other coating).  They do mutate readily.\nOnce inside a living cell, the virus sheds it’s coating and deactivates much of the genetic material of the cell, only allowing that which it needs or which do not interfere with their replication.  They then force the cell to replicate their genetic material as new virions which will be released when the cell ruptures.\nOpite gave good info on the size of the virus in terms of linear measurements.  Size, in terns of the number of bases runs from as few as 5,000 bases (single strand DNA) for the H-1 parvovirus to about a half a million base pairs in the largest.\nViruses are not considered to be alive.
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I don't know off the top of my head, but try looking here. It has loads of good and useful virology info.\nhttp://www-micro.msb.le.ac.uk/
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Only one from 1956 I could find by both of them:\nCrick, Francis, and James D. Watson. "Structure of Small Viruses." Nature 177, 4506 (10 March 1956): 473-475. Article. 3 Images. \nhttp://profiles.nlm.nih.gov/SC/B/B/Z/N/_/scbbzn.pdf
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http://en.wikipedia.org/wiki/Special:Search?search=reproduction+in+animals&go=Go
39999
Are viruses alive? \nAnyone with a cold or the flu virus feels as if they are under attack by some organism. But in the scientific community it's still an open-ended question. This is why viruses do not belong to a kingdom of living things. Just because a virus seems alive doesn't mean it is alive. After all, it's not even a single-celled organism.\n\nA virus is little more than a strand of DNA or RNA covered by a protein coating. Viruses are a thousand times smaller than bacteria and come in a wide range of shapes. Some look like weird, tall spiders whereas others look like prickly porcupinelike soccer balls.\n\n...\n\nAs humans, we like to classify things because it helps us understand the physical world. Viruses must have a host cell to live and reproduce. Outside of the host cell, viruses are pieces of genetic molecules that can do nothing by themselves. Viruses are right on the border between living and nonliving. Some biologists currently see the virus as a nonliving infectious particle. Other biologists disagree and suggest they are alive because of what happens inside the host cell. \n\nGetting a definite answer if viruses are alive or not may never happen. \n\nBut hey, that's life.
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I think it is important to understand that viruses don't live. They are simply dna or rna encased within a protein complex. They cause damage when they come in contact with host cells and are able to take them over. A more appropriate question would be how long can a virus stay airborne.\n\nAnswer\n\nIT can last for 3 days before death on objects that recieve dropplets of the DNA
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smallest to largest in a multicellular organism.\ncell-tissue-organ-organ system-organism
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Essentially the first question is right, but human viruses are very clever in that several coat layers are used. for example HPV, HSV (herpes).  Viruses are just proteins and DNA, nothing more.  They don't contain organelles, they don't reproduce independantly, they don't fulfill many life functions.
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Yes, viruses are alive. This is a fact, not an opinion. I am an atheist.\n\nIs a virus alive? \nYes - They reproduce which is a definite form of organization. True, they can not do it on their own, yet all living systems are open systems and depend upon their environment for survival. It is just that the environment a virus requires is another living cell. This is actually true for many symbiotic and parasitic cells. \nA virus is not a living machine . It is only part of a machine, namely the blueprints. The virus only provides the plans, the cell has done the real living work. Outside of its host the virus shows no living qualities.
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viruses, bacteria, fungi, or protozoan parasites
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The specific answer to that question can be found when you Google "burst size bacteriophage"....and select first line entitled\n"Bacteriophage Lecture Notes".....go down a few lines and it gives exact details.\n\nHope this helps.
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Viruses can't replicate on their own so you have to do it in a cell culture.  Look up "cell culture" and you will find lots of information as this has been done for quite a few years now.
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OK, after reading the answers so far I just have to say who are these people, and where are they getting their information from.  Many are stating that viruses are not considered living.  Well, anybody in the academic circle can tell you it is a matter of opinion, with many arguments for and against (mentioned by others).  I think, however, to answer your question, we should talk about the origins of viruses.\n\nThere is a current thoery out there that the origional viruses were actually defense mechanisms by early organisms against other organisms competing for the same niche. That is, the genes and functions were "excreted" into the environment with the purpose of attaching to something else, specifically, and destroying a host.  Over time, it is believed that evolution allowed the new hosts to survive these infections, yet stay infected, which allowed the nascent genes to become seperated from their origional "makers".  This then led to the viruses being able to evolve independently of the origional organisms.\n\nAs for why they don't have their own kingdom and classification, it is simple.  When the classification system was made, viruses were not known to exist.  Their diseases were, but they themselves were not.  It wasn't until leeweinhook in the 15th century that even bacteria were really discovered.  \n\nSo, as time passed, new organisms were found, and new classes were added to describe them.  The purpose of classification is two fold.  First, it should describe the organism.  Second, it should allow some sense of familial relationship to all other families.  Hence the new areas of prokaryotic, eukaryotic, and archaeobacteria.  \n\nBut with viruses, as others eluded to before, it wasn't certain that they were living at all, so how do we go about classifying them?  One scientist decided that instead of fighting an uphill battle, he would just start his own classification system, completely independent of the ones used for all other life forms. So, believe it or not, viruses are classified into families and genera, but just not placed into the classical naming system.  If you look iti up, you will find that all viruses have a latin name, from phage all the way to plant viruses.  \n\nI hope this helps you out.
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The volume of the virus is pi*(200^2)* 1500=1.884*10^7 cubic angstroms.   This goes into.24 cc 1.27*10^16 times.Divide 1 gm. by this figure and you get the weight of 1 virus=7.87*10^-17 grams.   That's the weight of a few million hydrogen atoms, which sounds about right.
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Plant viruses, like all other viruses, are obligate intracellular parasites that do not have the molecular machinery to replicate without the host. The plant viruses are defined as viruses pathogenic to higher plants. While this article does not intend to list all plant viruses, it discusses some important viruses as well as their uses in plant molecular biology.Most of the virus types that have been discovered infecting plants are single-stranded RNA viruses, and have rod-shaped capsids with protein units arranged in a spiral.One novel characteristic of Plant viruses is that some of the viruses, instead of having a segmented genome packaged into the same particle as happens in animal viruses, some of the plant virus species are multipartite. This is when, for example, in the Gemini virus genome there is two incomplete icosahedral particles joined as a pair and can contain two circular single stranded DNA molecules. This has been suggested that this method employed by plant viruses of separately packaging the genome solves the problem of organisation and packaging problems associated with the segmented genome.There are two major ways the viral diseases may spread: horizontal transmission and vertical transmission. Horizontal transmission means that the infection comes from the outside, usually through damage done to the plant by vegetative propagation, grafting, vectors (some viruses can propagate in plant host and vector animal) or mechanical transmission. Vertical transmission refers to the plant inheriting the disease from a parent; this is often via seed but is not as prevalent as horizontal transmission. Plant viruses frequently have the ability to stunt growth and diminish crop yield.\nThe outer surfaces of plants are composed of protective layers of waxes and pectin, but more significantly, each cell is surrounded by a thick wall of cellulose overlying the cytoplasmic membrane.There are single stranded, double stranded RNA and single stranded, double stranded DNA plant virus.
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Probably immunology or virology would be your best bets.  \n\nCapital letters are your friend :)
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First off jamesmusik84's is completely wrong. Please don't consider any of it. The second answer is along the right path, except I have no idea what the reference to antibiotic is suggesting and some viruses have RNA genomes but many more have DNA genomes. And as far as bacteria go, both RNA and DNA are present inside there cells.\n\nSo, the answer to your question. Let's start this way: Bacteria are small single-celled organisms. Unllike eukaryotic cells (like the ones that make up animals, plants, fungi and many single-celled organisms such as yeasts) which package their genetic material (DNA) in membrane structures called nuclei, bacteria (which are also referred to as prokaryotes) don't have a nucleus. Bacteria also don't have other organelles which are found in eukaryotes, such as endoplasmic reticulum, mitochandria, chloroplasts, golgi bodies, etc. But like eukaryotes, bacteria do have an outer lipid membrane.\n\nSo, you can think of bacteria of little fluid filled sacs. Along with eukaryotic, bacteria are an example of "cells" which are the smallest unit of living things on earth.\n\nViruses, on the other hand, do not have an outer membrane. They don't the capacity to make their own proteins. They don't have the capacity ot replicate or metabolize on their own -- of which bacteria (and eukaryotes) do. It's for this reason that we don't consider viruses "living" things. Viruses have to "infect" a cell -- injecting its genetic material inside -- and use the cell's metabolic machinery to reproduce.\n\nViruses are essentially small protein "capsules" that have a piece of genetic information packaged inside. Because viruses are required to infect a cell to propogate themselves, they are classified as obligate intra-cellular pathogens.\n\nViruses tend to only infect specific cell types. Some infect bacteria. Some infect plants. Others infect animals. The specificity of what a virus can infect is goes beyond whether they can infect bacteria, plants or animals. Usually viruses have to infect a very specific animal, plant or bacteria. And even in the case of viruses that infect animals and plants, not only do the infect specif animals, they are usually limited to a few cell types whithin that animal.\n\nTake HIV for example: to the best of my knowledge HIV only infects humans (i.e. the "H" in HIV -- Human Immunodeficiency Virus). But it doesn't just infect any human cell. HIV only infects white blood cells -- specifically a class of white blood cells called T cells (there are many other "classes" of white blood cells including such things as B cells, NK cells, neutrophils, basophils, eosinophils and macrophages).\n\nI hope this sheds some light on the matter.