what is basic difference between bacteria and virus?

Question

explain for common man as well as for not so common people

Answer 1

Bacteria (singular: bacterium) are unicellular microorganisms. They are typically a few micrometres long and have many shapes including spheres, rods, and spirals. The study of bacteria is bacteriology, a branch of microbiology. Bacteria are ubiquitous in every habitat on Earth, growing in soil, acidic hot springs, radioactive waste,[1] seawater, and deep in the earth's crust. Some bacteria can even survive in the extreme cold and vacuum of outer space. There are typically 40 million bacterial cells in a gram of soil and a million bacterial cells in a millilitre of fresh water; in all, there are approximately five nonillion (5×1030) bacteria in the world.[2] Bacteria are vital in recycling nutrients, and many important steps in nutrient cycles depend on bacteria, such as the fixation of nitrogen from the atmosphere. However, most of these bacteria have not been characterised, and only about half of the phyla of bacteria have species that can be cultured in the laboratory.[3]

There are approximately 10 times as many bacterial cells as human cells in the human body, with large numbers of bacteria on the skin and in the digestive tract.[4] Although the vast majority of these bacteria are rendered harmless or beneficial by the protective effects of the immune system, a few pathogenic bacteria cause infectious diseases, including cholera, syphilis, anthrax, leprosy and bubonic plague. The most common fatal bacterial diseases are respiratory infections, with tuberculosis alone killing about 2 million people a year, mostly in sub-Saharan Africa.[5] In developed countries, antibiotics are used to treat bacterial infections and in various agricultural processes, so antibiotic resistance is becoming common. In industry, bacteria are important in processes such as wastewater treatment, the production of cheese and yoghurt, and the manufacture of antibiotics and other chemicals.[6]

Bacteria are prokaryotes. Unlike animals and other eukaryotes, bacterial cells do not contain a nucleus or other membrane-bound organelles. Although the term bacteria traditionally included all prokaryotes, the scientific nomenclature changed after the discovery that prokaryotic life consists of two very different groups of organisms that evolved independently from an ancient common ancestor. These evolutionary domains are called Bacteria and Archaea.


A virus is a microscopic particle that can infect the cells of a biological organism. Viruses can only replicate themselves by infecting a host cell and therefore cannot reproduce on their own. At the most basic level, viruses consist of genetic material contained within a protective protein coat called a capsid. They infect a wide variety of organisms: both eukaryotes (animals, yeasts, fungi and plants) and prokaryotes (bacteria). A virus that infects bacteria is known as a bacteriophage, often shortened to phage. The study of viruses is known as virology, and those who study viruses are known as virologists. The word virus comes from the Latin, poison (syn. venenum).[1]

It has been argued extensively whether viruses are living organisms. Most virologists consider them non-living, as they do not meet all the criteria of the generally accepted definition of life. They are similar to obligate intracellular parasites as they lack the means for self-reproduction outside a host cell, but unlike parasites, viruses are generally not considered to be true living organisms. A definitive answer is still elusive because some organisms considered to be living exhibit characteristics of both living and non-living particles, as viruses do. For those who consider viruses living, viruses are an exception to the cell theory proposed by Theodor Schwann, as viruses are not made up of cells.

Answer 2

Viruses are tiny geometric structures that can only reproduce inside a living cell. They range in size from 20 to 250 nanometers (one nanometer is one billionth of a meter). Outside of a living cell, a virus is dormant, but once inside, it takes over the resources of the host cell and begins the production of more virus particles. Viruses are more similar to mechanized bits of information, or robots, than to animal life.
Whereas,Bacteria are one-celled living organisms. The average bacterium is 1,000 nanometers long. (If a bacterium were my size, a typical virus particle would look like a tiny mouse-robot. If an average virus were my size, a bacterium would be the size of a dinosaur over ten stories tall. Bacteria and viruses are not peers!) All bacteria are surrounded by a cell wall. They can reproduce independently, and inhabit virtually every environment on earth, including soil, water, hot springs, ice packs, and the bodies of plants and animals.

Most bacteria are harmless to humans. In fact, many are quite beneficial. The bacteria in the environment are essential for the breakdown of organic waste and the recycling of elements in the biosphere. Bacteria that normally live in humans can prevent infections and produce substances we need, such as vitamin K. Bacteria in the stomachs of cows and sheep are what enable them to digest grass. Bacteria are also essential to the production of yogurt, cheese, and pickles. Some bacteria cause infections in humans. In fact, they are a devastating cause of human disease.

Answer 3

Bacteria are considered a living thing. Viruses are not considered living. Thats the main difference. Viruses are like mutated strands of DNA.

Answer 4

Bacteria - microscopic unicellular prokaryotic organisms characterized by the lack of a membrane-bound nucleus and membrane-bound organelles.

Virus - parasite with a noncellular structure composed mainly of nucleic acid within a protein coat.

prokaryotic - a cellular organism (as a bacterium or a blue-green alga) that does not have a distinct nucleus.

Hope that this makes sense.

Answer 5

bacteria and virus are both micra-organisms but bacteria are living organisms which may be useful or harmful,whereas viruses are always harful and are considered as border between living and non-living organisms.viruses have the characteristics of both living and non-living organisms.

Answer 6

Bacteria are easier to kill, viruses usually have to run there course. A virus has a protected armor around them and they high jack healthy cells and inject their own DNA in the cell, so viruses are much worse!

Answer 7

A bacteria is cellular, while a virus is not. A virus is a string of RNA or DNA coated with proteins.

Answer 8

Viruses are, very minute. Bacteria are larger.

Viruses change constantly. Become different strand.

Answer 9

bacteria produce poison while a virus does not
bacteria feed while viruses do not

Answer 10

The main difference is the "spelling"