What is the difference between a Virus and bacteria?

Answer 1

Bacteria are cells, primitive though they may be, and given the right environment, they are fully self-replicating; life in every sense of the word.

Viruses are rarely more than a section of DNA or RNA encased in protein, and they cannot reproduce by themselves. They act as parasites, attaching themselves to living cells (sometimes bacteria!) and hijacking the cell's internal mechanisms to make more viruses. When the cell is full of viruses, it bursts and releases them.

Since viruses cannot reproduce by themselves, they form a gray area between living and non-living.

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.

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 single-celled living organisms. They have a circular chromosome, and most of them have a cell wall made of peptidoglycan. Some do not have a cell wall, and others have additional material within their walls. Viruses are acellular, meaning that they are not composed of cells at all. The most widely accepted definition of a living thing says that it must be made of one or more cells, so viruses are not alive. All viruses have a protein shell called a capsid that may vary considerably in its structure. Some viruses have DNA as their genetic material (and it may be either single or double stranded, as opposed to DNA in cells which is always double stranded). Other viruses have only RNA as their genetic material (no living cell can have only RNA without DNA as well).

Answer 4

Bacteria are cellular in nature like cells in the body. Virii are just DNA fragments that can replicate after infecting cells

Answer 5

Bacteria are members of the Monera kingdom. They have a nucleus like other living cells. Viruses have no nucleus and are not classified as belonging to one of the kingdoms of living things.

Answer 6

A virus (Latin, poison) is a microscopic particle that can infect the cells of a biological organism. At the most basic level, viruses consist of genetic material contained within a protective protein shell called a capsid; the existence of both genetic material and protein distinguishes them from other virus-like particles such as prions and viroids. They infect a wide variety of organisms: both eukaryotes (animals, 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. A virologist studies viruses.

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. Among other factors, viruses do not possess a cell membrane or metabolise on their own. 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 Theodore Schwann, as viruses are not made up of cells.

Origins
The origins of modern viruses are not entirely clear, and there may not be a single mechanism of origin that can account for all viruses. As viruses do not fossilise well, molecular techniques have been the most useful means of hypothesising how they arose. Research in microfossil identification and molecular biology may yet discern fossil evidence dating to the Archean or Proterozoic eons. Two main hypotheses currently exist[1]:

* Small viruses with only a few genes may be runaway stretches of nucleic acid originating from the genome of a living organism. Their genetic material could have been derived from transferable genetic elements such as plasmids or transposons, which are prone to moving around, exiting, and entering genomes.

* Viruses with larger genomes, such as Poxviruses, may have once been small cells which parasitised larger host cells. Over time, genes not required by their parasitic lifestyle would have been lost in a streamlining process known as retrograde-evolution or reverse-evolution. Both the bacteria Rickettsia and Chlamydia are living cells which, like viruses, can only reproduce inside host cells. They lend credence to this hypothesis, as they are likely to have lost genes enabling them to survive outside a host cell, in favour of their parasitic lifestyle.

Other infectious particles which are even simpler in structure than viruses include viroids, satellites and prions.

and

Bacteria (singular: bacterium) are microscopic, unicellular organisms. They are often coccus- (spherical) or rod-shaped and 0.5-5 µm in the longest dimension, although the wide diversity of bacterial diversity can display a huge variety of morphologies. The study of bacteria is known as bacteriology, a branch of microbiology.

Bacteria are ubiquitous in the environment, living in every possible habitat on the planet. There are typically ten billion bacterial cells in a gram of soil, and one hundred thousand bacterial cells in a millilitre of sea water. Bacteria play an important role in the cycling of nutrients in the environment, and many important steps in the nutrient cycle are catalysed exclusively by bacteria, such as the fixation of nitrogen from the atmosphere.

There are more bacterial cells on each of our bodies than there are our cells of our own and bacteria are a natural component of the human body, particularly on the skin and in the mouth and intestinal tract. Bacteria are important to human health, as they are the causative agent of many infectious diseases, including cholera and tuberculosis. Historically, bacteria have been responsible for such diseases as bubonic plague and leprosy, but after the discovery of antibiotics many bacterial diseases are able to be controlled.

Bacteria are also important to numerous industrial processes, such as wastewater treatment and more recently the industrial production of antibiotics and other chemicals.

The term "bacteria" has traditionally been generally applied to all microscopic, single-celled prokaryotes. Although this term remains in everyday use, the scientific nomenclature changed after the discovery that prokaryotic life actually consists of two very different lines of evolution (see three-domain system). Originally called Eubacteria and Archaebacteria, these evolutionary domains are now called Bacteria and Archaea.

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Answer 7

A virus is spread from person to person, a bacteria is within ones own body and is not contagious.

Answer 8

Viruses are nonliving! Biggest difference out there.