Certain viruses are known as retroviruses, based upon which of the following characteristics
Section 6.3 Viruses: Structure, Function, and Uses. A virus is a small parasite that cannot reproduce by itself. Once it infects a susceptible cell, however, a virus can direct the cell machinery to produce more viruses. Most viruses have either RNA or DNA as their genetic material.he surface of viruses includes many copies of one type of protein that binds, or adsorbs, specifically to multiple copies of a receptor protein on a host cell. This interaction determines the host range of a virus and begins the infection process (Figure 6-15). Retroviridae is a family of enveloped viruses that replicate in a host cell through the process of reverse transcription. A retrovirus is a single-stranded positive-sense RNA virus with a DNA intermediate and, as an obligate parasite, targets a host cell.ithin the cell, reverse transcriptase creates a complementary strand of DNA from the retrovirus RNA and the RNA is degraded; this strand of DNA is known as cDNA (4). The cDNA is then replicated, and the two strands form a weak bond and go into the nucleus (5). A virus is a microscopic, non-cellular, infectious agent that has two characteristics: It has genetic material (either DNA or RNA) inside a protective protein coat (called a capsid). Uniquely, viruses may contain single or double stranded nucleic acid.ach virus can only use certain proteins which influences which cells they are able to infect (a property called 'tropism'). One inside, the virus must shed its protein coat and prepare to be replicated. The process of replication will differ based upon whether or not the virus is DNA based or RNA based. Retroviruses are RNA-containing viruses that use the enzyme reverse transcriptase to copy their RNA into the DNA of a host cell. Retroviruses have been isolated from a variety of vertebrate species, including humans, other mammals, reptiles, and fish.icensed from Columbia University Press. retrovirus, type of RNA virus that, unlike other RNA viruses, reproduces by transcribing itself into DNA. An enzyme called reverse transcriptase allows a retrovirus's RNA to act as the template for this RNA-to-DNA transcription. retrovirus A virus whose genetic material consists of RNA and which is able, by means of the enzyme reverse transcriptase, to manufacture its DNA equivalent and insert it into the genome of its host species.icensed from Columbia University Press. retrovirus, type of RNA virus that, unlike other RNA viruses, reproduces by transcribing itself into DNA. An enzyme called reverse transcriptase allows a retrovirus's RNA to act as the template for this RNA-to-DNA transcription. A virus is a small, infectious agent that is made up of a core of genetic material surrounded by a shell of protein. The genetic material (which is responsible for carrying forward hereditary traits from parent cells to offspring) may be either deoxyribonucleic acid (DNA) or ribonucleic acid (RNA).n order to produce new copies of itself, a virus must use the host cell's reproductive machinery.. The newly made viruses then leave the host cell, sometimes killing it in the process, and proceed to infect other cells within the organism. An oncovirus is a virus that can cause cancer. This term originated from studies of acutely transforming retroviruses in the 1950–60s, often called oncornaviruses to denote their RNA virus origin. It now refers to any virus with a DNA or RNA genome causing cancer and is synonymous with tumor virus or cancer virus..The vast majority of human and animal viruses do not cause cancer, probably because of longstanding co-evolution between the virus and its host.t now refers to any virus with a DNA or RNA genome causing cancer and is synonymous with tumor virus or cancer virus.. The vast majority of human and animal viruses do not cause cancer, probably because of longstanding co-evolution between the virus and its host. A virus is a microscopic organism that can replicate only inside the cells of a host organism. Most viruses are so tiny they are only observable with at least a conventional optical microscope.his is due to the fact that a virus can inherit a genetic mutation and is also subject to similar natural selection processes of cellular organisms. A virus cannot be labelled simply, therefore, as inanimate or lifeless. All other organisms are based on double stranded DNA. To reproduce itself, a virus needs to infect a living cell. The genetic material is inserted into the cell, and the reproductive machinery of that cell is then effectively hijacked: the cell starts to produce components of new virus particles.These components spontaneously self-assemble and the new virus particles can then infect other cells, where the same process happens.ach virus can only use certain proteins which influences which cells they are able to infect (a property called 'tropism'). One inside, the virus must shed its protein coat and prepare to be replicated. The process of replication will differ based upon whether or not the virus is DNA based or RNA based. Licensed from Columbia University Press. retrovirus, type of RNA virus that, unlike other RNA viruses, reproduces by transcribing itself into DNA. An enzyme called reverse transcriptase allows a retrovirus's RNA to act as the template for this RNA-to-DNA transcription.icensed from Columbia University Press. retrovirus, type of RNA virus that, unlike other RNA viruses, reproduces by transcribing itself into DNA. An enzyme called reverse transcriptase allows a retrovirus's RNA to act as the template for this RNA-to-DNA transcription.
A DNA or RNA genome.