What is a parasite?

The parasite is an organism that uses another organism to live alive. Some parasitic relationships are harmless, while in other cases the parasite may damage or even kill its host. A study of parasitism is an extensive field because parasites can be found across the biological kingdoms and many animals organize one or more parasites during their lives. Many organisms also pass through the parasitic stage at some point during their lives. In Greece and Rome, some people made dining in the homes of other full -time occupations, sometimes called "professional guests dinner". Like biological parasites, these individuals used their hosts to eat and did not bring anything to the table except for the conversation for dinner. The existence of parasites has long been known in biology, although the development of quality microscopes has significantly expanded human knowledge of parasites. In addition, the parasite must not bring anything to the relationship and create an arrangement that may be neutral or harmful but never positive. Numerous organisms are connected to use their mutual sides in the biological process called symbiosis - in this case the arrangement is mutually beneficial for both creatures and is not considered parasitism.

Some of the well -known parasites include mites, tapeworms, mistletoe and fleas. Parasites live in many different ways; For example, some cannot live as soon as their host dies, while others can switch hosts or continue to prosper with dead hosts until their nutrients are consumed. There is some dispute by whether bacteria and viruses should be considered parasites; From a medical point of view, a parasite is usually an eukaryotic organism, which means it has a complex cellular structure, unlike bacteria.

parasites living inside the host are called endoparatéti or internal parasites. Many human diseases are caused by internal parasites that mayTo infest the intestinal tract, causing symptoms such as diarrhea and vomiting. Various treatment is used for parasitic infection depending on the organism involved. Ectoparasites live outside the hosts and are generally able to switch hosts. When the parasites of prey on other parasites are known as epiparasite.