what is self-replicating system, in term of biology?
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Any molecule (such as an RNA) that can make a copy of itself without being destroyed in the process is self-replicating.
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All the answers are here --> http://en.wikipedia.org/wiki/Cell_%28biology%29\n(and in your book)
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Actually it makes perfect sense.  Things naturally pair together, whether it be by gravity, magnetism, parasitism or whatever reason.  eventually enough atoms will link together for convienience to form a protein, enough protiens will link together to form a cell, then we have life.  cells will then pair together to form tissues, which will pair with other tissues to increase their survival rate giving us more complex organisms.  See the steps yet?  Following that we get to higher functioning organisms.  An organism's cells reproduce millions of times in that organisms lifetime and every time the DNA is replicated there is a chance for a mistake.  How many typos do you make typing a paper?  This is where variation comes from.  Evolution and extinction come from natural selection.  As the world changes things have to adapt those that don't die. If they didn't die we wouldn't call it evolution.
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Yes they do and therefore are able to propogate their own kind (also able to show variations by genetic recombination). DNA or RNA both can be used as the building blocks. \n\nThey however try to carry a small baggage when traveling and use the host cell machinary to produce stuff that they need along the way.\n\nA virus is a submicroscopic parasitic particle that infects cells in biological organisms. The study of viruses is virology.\n\nViruses are obligate intracellular parasites that lack the cellular machinery for self-reproduction. Viruses infect eukaryotes and prokaryotes such as bacteria; viruses infecting prokaryotes are also known as bacteriophages or phages. Typically viruses carry a small amount of genetic material, either in the form of DNA or RNA, but not both, surrounded by some form of protective coat consisting of proteins, lipids, glycoproteins or a combination. The viral genome codes for the proteins that constitute this protective coat, as well as for those proteins required for viral reproduction that are not provided by the host cell.\n\nViruses are non-living particles that can only replicate when an organism reproduces the viral RNA or DNA. Viruses are considered non-living by the majority of virologists because they do not meet all the criteria of the generally-accepted definition of life. Among other factors, viruses do not move, metabolize, or decay on their own. However, a comprehensive definition of life is still somewhat elusive since some bacteria (considered living) like rickettsia exhibit both characteristics of living and non-living particles.\n\nBecause viruses are acellular and do not have their own metabolism, they must utilize the machinery and metabolism of the host for the purpose of self-replication. Before a virus has entered a host cell, it is called a virion — a package of viral genetic material. Virions can be passed from host to host either through direct contact or through a vector, or carrier. Inside the organism, the virus can enter a cell in various ways. Bacteriophages—bacterial viruses—attach to the cell wall surface in specific places. Once attached, enzymes make a small hole in the cell wall, and the virus injects its DNA into the cell. Other viruses, such as HIV, enter the host via endocytosis, the process by which cells take in material from the external environment. After entering the cell, the virus's genetic material begins the destructive process of causing the cell to produce new viruses.\n\nThere are three different ways genetic information contained in a viral genome can be reproduced. The form of genetic material contained in the viral capsid, the protein coat that surrounds the nucleic acid, determines the exact replication process.\n\nSome viruses have DNA which is replicated by the host cell along with the host's own DNA.\n\nThere are two different replication processes for viruses containing RNA. In the first process, the viral RNA is directly copied using an enzyme called RNA replicase. This enzyme then uses that RNA copy as a template to make hundreds of duplicates of the original RNA. A second group of RNA-containing viruses, called the retroviruses, uses the enzyme reverse transcriptase to synthesize a complementary strand of DNA so that the virus' genetic information is contained in a molecule of DNA rather than RNA. The viral DNA can then be further replicated using the resources of the host cell.\n\nBacteriophages have two cycles called the lytic cycle and lysogenic cycle. In the lytic cycle the host cell undergoes lysis (the breaking open of the cell to release viral particles), biosynthesis, maturation and finally release. In the lysogenic cycle viral replication does not immediately occur, but replication may take place some time in the future. some viruses e.g. lambda are capable of carrying out both cycles. In the lytic cycle the cell is soon destroyed and the viruses made will have to find new host. However during the lysogenic s
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A virus does not fulfill the minimal criteria of life.\nA virus is a chemical construct, as others had said before, it is not capable of reproducing itself.\nA chromosome is a very large collection of chemicals, it may be very similar to a virus. It is part of a living organism, by itself, it is not. \nA virus may 'attack' cells and force them to replicate itself, a chromosome doesn't do that; it doesn't have to. You could think of a chromosome as a virus having found its perfect spot; it no longer has to invade cells...
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Deoxyribonucleic acid; a nucleic acid that consists of two long chains of nucleotides twisted together into a double helix and joined by hydrogen bonds between complementary bases adenine and thymine or cytosine and guanine; it carries the cell's genetic information and hereditary characteristics via its nucleotides and their sequence and is capable of self-replication and RNA synthesis.
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Abiogenesis: The supposed development of living organisms from nonliving matter. Also called autogenesis , spontaneous generation . \n\nBiogenesis: The principle that living organisms develop only from other living organisms and not from nonliving matter.\n\nAs a biochemist, I am forced to believe that everything started with abiogenesis. Molecules got together created amino acids, amino acids created proteins and proteins created organisms. Presently, it is more correct to state that we live in a world where biogenesis occurs. Nevertheless, if abiogenesis occurred before, it does not mean it is not happening presently. All you need is the right molecules on the right time and space (maybe a lightning strike). The energy of a lightning is sufficient to cause chemical reactions.
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Conjugation \nModern bacteria reproduce by splitting in two - that is, they have asexual reproduction. But a bacteria can join temporarily with another bacteria to swap genetic fragments. This conjugation process is why so many bacteria have recently become antibiotic resistant. The process permits bacteria to form a sort of community.\n\nBiological reproduction is the biological process by which new individual organisms are produced. Reproduction is a fundamental feature of all known life; each individual organism exists as the result of reproduction by an antecedent. The known methods of reproduction are broadly grouped into two main types: sexual and asexual reproduction.\n\n\nso by this v can see that asexual reproduction is conjugation
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The insertion of foreign DNA fragments into a cell/organism which will replicate the DNA and integrate it into its own genome
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The answer to your question is (C). \n\nEvery living organism is made up of one or more cells, all cells arise from preexisting cells, the smallest living organisms are single cells, and cells are the functional units of multicellular organisms.\n\n"Virus - a non cellular parasitic particle that consists of a protein coat surrounding a strand of genetic material; multiplies only within a cell of a living organism (the host)."
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/Darwinian theory of self selection [Boolean=1]\nDUH!!! NOW they do....\n/Darwinian theory of self selection [Boolean=0]
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4.  DNA is double stranded so if it replicates once you have four strands.
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biology is the study of living things
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By definition, viruses cannot replicate themselves-they do not contain the machinary to do this, and never have.  Thus, in order for a virus to replicate, it must have available some other form of life which can carry out replication.  The simplest forms of life we know are extremophiles, found in deep sea vents and places like Yellowstone...prior to this discovery, it was thought cyanobacteria were the simplest.  At any rate, both extremophiles and cyanopacteria are forms of bacteria, and each has viruses that infect them- Since viurses depend on bacteria for replication, but bacteria do not depend on viruses, bacteria must have come first.  If a lonely virus did evolve before anything else, it would have degenerated without progeny.  BTW, biologists do not consider viruses "alive" because they cannot replicate...but again, thats just a human definition.
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this is a good question. what decides a cell living or nonliving is its metabolic activity. ..now you got me thinking... \n\nBut  to clear some confusion, they don't have nucleus, and that's why they can't reproduce by themselves.\n\nK...finally got some info from a very good friend, a hematologist. Here is what he says...\n\n"The question you asked is a very very deep one indeed.  In fact, we can have a very lively debate about it.  It is a very philosophical question, in that it's equivalent to asking, "Is virus a living organism?"  If we define life, as you say, by metabolic activities, then yes, red blood cell is a living cell.  Red blood cell uses the metabolic pathway of glycosis to generate energy.  It also has a variety of proteins and enzymes responsible for signal transduction.\n \nHowever, a red blood cell is a terminally differentiated cell and more than that it lacks the genetic material, the means and the mechanism to replicate.  Given that one of the primary goal of life is to have "offsprings" either through asexual replication or sexual duplication, red blood cell lacks that ability.  However, the progenitor of red blood cell (hematopoietic stem cells) does have the ability to replicate and differentiate."
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lysogenic (copies itself in genome of other cells, cell divide...later it enters lytic cell and burst to spread virus\n\nAnswer: Lysogenic cycle
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There is a term in biology called Homeostasis, what it basically says is that a biological system will maintain itself in equilibrium suited to the environment. Small organisms can reproduce at rates that are astonishing, if the environment could support a large increase in population, the plankton would naturally increase their numbers. Actually most biologists think that organisms reproduce at rates larger than the environment can handle, and the die off of the organisms that environment can't handle is part of natural selection.\n\nSo long story short, as nice as it would be to produce micro-organisms to handle our carbon output, I don't think it's actually feasible to do. I don't have any actual numbers, but it would be interesting to know the amount of plankton-like organisms we would need to curb our carbon output, I bet the actual number itself would be astonishing and impossible to do, at least in any meaningful time-frame.