Organisms and viruses

Viruses do not have the ability to reproduce by themselves, so they fail this requirement to be defined as a living organism. Another characteristic of living things is homeostasis. Homeostasis is the ability to maintain a controlled environment. Viruses do not have the ability. Viruses are microscopic particles that invade and take over both eukaryotic and prokaryotic cells. They consist of two structures, which are the nucleic acid and capsid. The nucleic acid contains all genetic material in the form of DNA or RNA, and is enclosed in the capsid, which is the protein coating that helps the virus attach to and penetrate the host cell.

In some cases, certain viruses have a membrane surrounding the capsid, called an envelope. This structure allows viruses to become more.

When viruses are outside of their host they are inactive and seem dead. When inside their hosts, viruses become active and are capable of replicating internally and survive independently of their host. In order to determine if viruses are alive we must look at the criteria set for an alive organism and a dead one.

The definition of a death in an organism is when. The question was asked are viruses living or nonliving. Well after reading the first five pages of my biology book, I learned that there are six things that every scientist agrees with.

Scientist agree with the fact that organisms contain levels of organization, the ability to acquire materials and energy, maintain an internal environment, respond to stimuli, the ability to reproduce and develop, and the ability to adapt and evolve to changing conditions.

After finding out a little about each one. Since viruses were first discovered in , there has been an ongoing debate of whether or not a virus can be classified as living organisms. A virus is composed of two simple components: a genome and a protein coat to protect this genome, and they are known to infect living host cells to replicate. From this definition, it does not define either the possibility of whether or not that a virus is alive. It gives the structure and function of the virus, but not the general rules that are needed to.

The debate on whether viruses are living organisms or not is very complicated and requires a large amount of thinking. This is caused by their complicated structure and the fact that it shares some qualities of life and some qualities that don't show life. Bacteria, on the other hand, are living organisms that consist of single cell that can generate energy, make its own food, move, and reproduce typically by binary fission.

This allows bacteria to live in many places—soil, water, plants, and the human body—and serve many purposes. They serve many vital roles in nature by decomposing organic matter maybe not that vital to anyone who's forgotten leftovers in the back of the fridge and by converting nitrogen, through nitrogen fixation , to chemicals usable by plants.

Bacteria even know how to work as a team through something called quorum sensing. Bacteria are giants when compared to viruses. The smallest bacteria are about 0. This makes most viruses submicroscopic , unable to be seen in an ordinary light microscope. They are typically studied with an electron microscope. Their mode of infection is different.

Because of their distinct biochemistry, it should come as no surprise that bacteria and viruses differ in how they cause infection. Viruses infect a host cell and then multiply by the thousands, leaving the host cell and infecting other cells of the body.

A viral infection will therefore be systemic , spreading throughout the body. Pathogenic bacteria have a more varied operation and will often infect when the right opportunity arises, so called opportunistic infection. The infection caused by pathogenic bacteria is usually confined to a part of the body, described as a localized infection. These infections may be caused by the bacteria themselves or by toxins endotoxins they produce.

Examples of bacterial disease include pneumonia , tuberculosis , tetanus , and food poisoning. Researchers debate whether a virus is even "alive. By itself, a virus can accomplish nothing—it needs to enter a living thing to perform its only function, which is to replicate. When a virus gets inside a human body, it can hijack a person's cellular machinery to produce clones of itself, overtaking more cells and continuing to reproduce. When the virus reproduces faster than the immune system can control it, it begins to destroy cells and harm the body.

Viruses are also the smallest germ, making them generally the easiest to contract—they're so tiny they can spread through the air in a cough or a sneeze. Some viruses also are spread by mosquitoes or through bodily fluid.

Since each virus is very different, no one drug exists to attack whichever virus is in your body. Vaccines give preemptive protection from certain viruses by training the body's immune system to recognize and attack a specific virus. Common forms: Bacteria cause food poisoning, strep throat and urinary tract infections , as well as infections such as tuberculosis.

Bacteria are bigger and more complex than viruses, though they can still spread through the air. A bacterium is a single cell, and it can live and reproduce almost anywhere on its own: in soil, in water and in our bodies.

For the most part, we live peacefully with bacteria—the colonies in our guts are helpful to us and strengthen our immune system. But like viruses, bacteria can also harm us by replicating quickly in our bodies, killing cells.

Some bacteria also produce toxins which can kill cells and cause an outsized, damaging immune reaction. Broad-spectrum antibiotics were developed to kill bacteria in our bodies and in the food supply by inhibiting their growth.

But bacteria are extremely adaptive and can quickly evolve to evade antibiotics. Bacteria share their antibiotic-resistant genes with each other, meaning more strains generate resistance to the drugs we use. Common forms: Fungi are responsible for causing conditions such as yeast infections , valley fever and meningitis.