With the recent worldwide spread of the coronavirus (COVID-19 or 2022-nCoV), there are more and more doubts that arise about the strange world of viruses, among them, if viruses are living beings or inert beings and how they work. For decades, science has been revealing information about viruses, their main vectors of spread and the various diseases they cause, being considered today as the smallest infectious agents that exist. Among these viral diseases, beyond the current coronavirus and the common flu, those caused by the well-known Human Immunodeficiency Virus (HIV), Ebola virus, chickenpox and measles, as well as the herpes virus and the virus of the papilloma.
In this interesting article by Ecologist Verde you will find all the information you need to learn more about the surprising viral world, as well as the answer to the curious question: Are viruses living beings or not?
Are viruses living beings or not?
Currently and scientifically speaking, viruses are NOT considered living beingsRather, they are constituted as molecular and protein aggregates devoid of their own life.
Why Viruses Are Not Living Things
- Among the main reasons why they cannot be considered living beings, highlights their inability to live and reproduce freelyIn other words, they always need another organism (unicellular or multicellular), which they infect in order to survive and reproduce their genetic material.
- Viruses have no cells, so they do not have tissues, organs or any type of enzymatic machinery that allows them to fulfill their reproductive function, so they are considered obligate intracellular parasites that they need the cellular resources of the living beings they infect in order to survive, these being both bacteria and other microorganisms such as animals, plants and human beings.
- It is easy not to group them within living beings because lack vital functions that living beings do develop, such as food, respiration, communication with the environment, energy capture and reproduction with the exchange of genetic material.
This last function is probably the most curious and surprising in the world of viruses, so in the next section we will see in detail how viruses reproduce and the main characteristics of this process.
How Viruses Reproduce
The spread or reproduction of viruses is based on processes of constant replication of your genetic material, making use of the genome of a living being, which serves as a template to which they incorporate their own genetic information.
It is a much simpler process than that carried out by living beings to reproduce, since in the case of viruses, they simply injects your genetic information into DNA and associated enzymatic machinery of the host organism that they have infected, with the consequent creation of new virus replicas, completely identical to the original.
When it comes to reproducing, viruses can follow two types of reproductive cycles, depending on whether they involve lysis or death of the cell they infect or not. So these are the two types of virus reproduction:
Lytic cycle of viruses
It involves the lysis and death of the host cell. Viruses, after using the cellular enzymatic machinery to reproduce or propagate and create new identical viruses, end up lysing the cell with the consequent release of the new viruses and their rapid spread, with the aim of infecting new cells and continuing their multiplication.
Lysogenic cycle
In this case, the viruses do not break the host cell at first, but instead use the enzymatic machinery of the cells they infect to ensure their own growth and duplication of genetic material. Once they consider their development sufficient, they revert to a lytic cycle, with the consequent death of the host cell and release of the new viruses, thus continuing their parasitic or infectious activity.
How Viruses Are Classified
Thanks to virology, science in charge of study of viruses, there is more and more information regarding the structure and mechanisms of infection of complex and microscopic viruses. In this way, when it comes to classify virusesThese are included within different taxonomic families, following classifications that attend to different parameters, such as:
Classification of viruses according to their genetic material
- Adenovirus (DNA)
- Reovirus (RNA)
- Retrovirus (RNA)
- Paramyxovirus (RNA)
Classification of viruses according to their shapes and structures
- Coronavirus
- Orthomyxovirus
- Picornavirus
Classification of viruses according to the organisms they infect
- Bacterial virus: T-pair bacteriophage
- Plant viruses: Tobacco mosaic virus
- Animal Viruses: Herpesvirus, Parvovirus, Poxvirus
We recommend you learn more about them and about other infectious or parasitic organisms with this other Green Ecologist article about biological contamination: what it is, types and examples.
If you want to read more articles similar to Are viruses living beings?, we recommend that you enter our Biology category.
Bibliography- Sierra, J.J. (2004) Taxonomy and human immunodeficiency virus. Mexican Journal of Clinical Pathology, Redigraphic. Volume 61 (1).
- Delgado, M. I. & Hernández, J. L. (2015) Viruses, are they living organisms? Discussion in the training of Biology teachers. Enrique José Varona Pedagogical University, Havana, Cuba. Volume 61, pp. 1-7.
- Raoult, D., Audic, S., Robert, C., Abergel, C., Renesto, P., Ogata, H., … & Claverie, J. M. (2004). The 1.2-megabase genome sequence of Mimivirus. Science, 306(5700), 1344-1350.
