Virus Concepts

A virus is a form of life that replicates itself and infected cells in a person’s body or other organisms. A virus is an unstable element which will replicates itself without any control. A virus can infect various types of living things, such as plants, animals, and bacteria. Although a virus may seem like something harmless, viruses are a serious threat to the health of the people who become infected with them. If a person is not careful when they are exposed to a virus, they can easily contract a virus and harm themselves and others.

A virus is a single-celled organism which reproduces by inserting its own genetic code into other living cells. Viruses are usually very small and have a simple structure, so a microscope is not required to see them. The term ‘virus’ comes from the Greek word virusa, which means “a cell shaped like a grain”. Since there is no external symptom associated with the presence of a virus, it can be contagious. Any type of motion, for instance shaking hands, sharing utensils, breathing through the mouth or touching an area contaminated by a virus, will cause the virus to spread, similarly to a common cold.

There are several different types of viruses. Some viruses only affect one type of cell, while others target many different types of cells. The most commonly known types of viruses are; AIDS-related illnesses caused by retroviruses, the human immunodeficiency virus (HIV) that attacks the immune system, and various types of bacteria viruses. Many types of animal viruses can also affect humans. For example, the SARS virus that was responsible for the recent SARS outbreak was responsible for infecting more than 10% of the African countries affected by the disease.

There are several types of viruses that affect cells in the laboratory but are too specific to be classified as viruses. These include; enveloped viruses, envelope protein viruses, liposome and nucleoplasmic viruses, envelope antigens, and cellular fusion viruses. Enveloped viruses are enveloped within an envelope that contains nonliving material such as RNases and proteins, which is then introduced into a living cell. For instance, enveloped viruses containing a DNA polymer that is designed to reproduce themselves are commonly called dicistase and enveloped viruses containing a genetic RNA sequence that is meant to reproduce themselves are called RNases. envelope protein viruses are enveloped in a liposome.

There are three common ways in which viral infections occur, they are: direct contact, indirect contact without physical contact. Direct contact is the most common way in which viruses are spread. This usually refers to such diseases as colds and other bacterial infections. Indirect contact refers to conditions in which the virus spreads through the fluid that circulates within the body. Examples of these fluids are blood, lymph, saliva and sweat. Contact without physical contact means that the virus spreads through some sort of chemical or biological medium such as semen, secretions and aerosols.

Nucleic acid contains coding for amino acids that are shared between living cells. The human genome encodes approximately 2.5 billion letters of genetic code that governs the functioning of all cells, which are then carried by the sperm and the egg. There are several ways in which the genetic material can be passed on from one generation to the next. For instance, it can be transmitted directly from the mother to the child during intercourse or it can be inherited from the parents via genetics. It also can be transmitted between organisms by inheritance. Some viruses can act like retroviruses, invading a host and triggering the generation of a new genome with a completely different set of genes.