How do viruses reproduce wikipedia

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; often only the symptoms can be treated.

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. Some of these drugs stop DNA synthesis, preventing the virus from replicating.

Although viruses can have devastating health consequences, they also have important technological applications. Viruses are particularly vital to gene therapy.

Because some viruses incorporate their DNA into host DNA, they can be genetically modified to carry genes that would benefit the host. Some viruses can even be engineered to reproduce in cancer cells and trigger the immune system to kill those harmful cells. Although this is still an emerging field of research, it gives viruses the potential to one day do more good than harm.

Antibiotics do not stop viruses. Also called the flu. The audio, illustrations, photos, and videos are credited beneath the media asset, except for promotional images, which generally link to another page that contains the media credit. The Rights Holder for media is the person or group credited. Tyson Brown, National Geographic Society. National Geographic Society. For information on user permissions, please read our Terms of Service.

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If a media asset is downloadable, a download button appears in the corner of the media viewer. SARS-CoV-2 is an enveloped virus, meaning that it has a lipid membrane an outer covering made of a fat-like substance.

The protein spikes covering the virus's envelope allow it to bind to receptors on the host cell's lipid membrane, leading to infection and sometimes illness. Share this. Viruses cannot reproduce on their own. Uncoating: The viral capsid is removed and degraded by viral enzymes or host enzymes releasing the viral genomic nucleic acid. Replication: After the viral genome has been uncoated, transcription or translation of the viral genome is initiated. It is this stage of viral replication that differs greatly between DNA and RNA viruses and viruses with opposite nucleic acid polarity.

This process culminates in the de novo synthesis of viral proteins and genome. Assembly: After de novo synthesis of viral genome and proteins, which can be post-transrciptionally modified, viral proteins are packaged with newly replicated viral genome into new virions that are ready for release from the host cell. This process can also be referred to as maturation.

Virion release: There are two methods of viral release: lysis or budding. Lysis results in the death of an infected host cell, these types of viruses are referred to as cytolytic. An example is variola major also known as smallpox. Enveloped viruses, such as influenza A virus, are typically released from the host cell by budding.

It is this process that results in the acquisition of the viral phospholipid envelope. These types of virus do not usually kill the infected cell and are termed cytopathic viruses.