Diversity+of+Life-Protists

** Diversity of Life **
===** ﻿Kingdon: Protists ** === Plasmodium falciparum


 * __Contents__
 * 1) Taxonomy
 * 2) Introduction
 * 3) Morphological Features
 * 4) Anatomical/Physiological Features
 * 5) Range of Habitat
 * 6) Interesting Facts
 * 7) References ||

** Taxonomy **


 * Kingdom || Protista ||
 * Phylum || Apicomplexa ||
 * Class || Sporozoasida ||
 * Order || Eucoccidiorida ||
 * Family || Plasmodiidae ||
 * Genus || Plasmodium ||
 * Species || falciparum ||

Protists are a group of diverse eukaryotic microorganisms that are either unicellular, or multicellular without specialized tissues which separates them from other eukaryotes such as fungi, animals and plants. As we travel deeper inside the kindom of protista, we find several phylums that are quite unique from each other. The phylum apicomplexa, or apicomplexia, are a group of unicellular parasitic-protists that are able to penetrate the cell of a host, usually killing the host cell as a result in the process.

** Introduction **

Most commonly known for being the cause of the malaria, the genus Plasmodium contains over 200 species, at least 10 of which infect humans. Of all these species, Plasmodium falciparum is the deadliest of them all, accounting for 91% of all 247 million human malarial infections, and 90% of the deaths. Plasmodium falciparum is transmitted from one host to another through the female Anopheles mosquito. Around the world, malaria is the most significant parasitic disease of humans and more children die from it worldwide than any other infectious disease.

** Morphological Features **

Usually, when a patient is diagnosed with malaria, medical professionals will examine a blood film of the patient to determine the species that caused the infection, seeing as each species has its own unique appearance and physical characteristics. In Plasmodium falciparum, only early trophozites and gametocytes are seen in the blood film, as shown on right. Sometimes, faint comma shaped dots known as "Maurer's dots" can be found on the red cell surface of the patient.

** Anatomical/Physiological Features **

As we mentioned in the introduction to the apicomplexa phylum, although Plasmodium falciparum does not have any significant organelles for movement such as flagella or cilia, it does have a unique anatomical feature inside it: the apicoplast. Apicoplasts are non-photosynthetic plastids that are found in most Apicomplexa, especially malaria parasites such as Plasmodium falciparum, and are vital to parasite survival. When a parasite's apicoplast is destroyed, the destruction of the apicoplast does not immediately kill the parasite, but rather prevents it from penetrating new host cells.

Apicoplasts synthesize fatty acids and other metabolites tat are needed for Plasmodium falciparum to enter the cell of the host. Once inside the host cell, Plasmodium falciparum can use the host cell as a reproduction base, reproducing even more parasites to affect more cells.



** Range of Habitat **

The host cycle of Plasmodium falciparum is a long and complex one. The human infection usually begins with the bite of an infected Anopheline mosquito. The microgametocytes from the male Anopheline mosquito fuses with the macrogametocytes from the female Anopheline mosquito during a suxual phase, in which a zygote is produced, which develops into a sporozoite-filled oocyst in approximately 20 days. When the oocysts rupture, the sporozoites move to the salivary glands. Then, the sporozoites of Plasmodium falciparum are released from the salivary glands of the mosquito when they are taking a meal of blood and enter the blood stream.The sporozoites travel by the bloodstream and are transported to the liver. The sporozoites are cleared from the circulation within 30 minutes. There, they undergo and asexual reproduction process called schizogony, which first divides the nucleus, followed by the division of the cytoplasm to produce merozoites. The liver cells are then the host cells, or the hepatocytes. After 14 days of reproduction, the merozoites burst from the host cell, over 1000 of merozoites per cell, killing the hepatocytes. Then, individual merozoites moves back to the blood stream to invade the red blood cells (erythrocytes). The merozoites then undergo an additional round of reproduction, producing 12~16 merozoites within a schizont. The length of time needed for this erythrocytic cycle differs between species; in Plasmodium falciparum’s case, it takes around 48 hours. Then, like before with the hepatocytes, the merozoites kill the erythrocytes when released, and invade more erythrocytes. The rupture of the erythrocytes (red blood cells) is the main cause of the malaria symptoms of fever and chills. However, not all of the merozoites divide into schizonts, but rather become sexual forms of the male and female gametocytes, which are picked up by the Anopheline mosquitoes and reproduce inside them, and the whole cycle repeats again. Most cases of malaria occur in Africa.




 * Interesting Facts **


 * For every liver cell it infects, more than 1000 merozoites can burst from it.
 * As of 2006, Plasmodium falciparum accounted for 91% of all 247 million human malarial infections (98% in Africa) and 90% of the deaths.


 * References **


 * 1) "Apicomplexa: Facts, Discussion Forum, and Encyclopedia Article." AbsoluteAstronomy.com. Web. 15 Nov. 2010. .
 * 2) "Apicoplast: Facts, Discussion Forum, and Encyclopedia Article." AbsoluteAstronomy.com. Web. 15 Nov. 2010. .
 * 3) Contrast, By. "Plasmodium: Facts, Discussion Forum, and Encyclopedia Article." AbsoluteAstronomy.com. Web. 15 Nov. 2010. .
 * 4) "Infection by Plasmodium Species." Michigan State University. Est. 1855. East Lansing, Michigan USA. Web. 15 Nov. 2010. .
 * 5) "Malaria Life Cycle." Universität Tübingen - Landingpage. Web. 15 Nov. 2010. <http://www.uni-tuebingen.de/modeling/Mod_Malaria_Cycle_en.html>.
 * 6) "Plasmodium Falciparum." Academic Dictionaries and Encyclopedias. Web. 15 Nov. 2010. <http://en.academic.ru/dic.nsf/enwiki/297414>.
 * 7) "Plasmodium Falciparum: Facts, Discussion Forum, and Encyclopedia Article." AbsoluteAstronomy.com. Web. 15 Nov. 2010. <http://www.absoluteastronomy.com/topics/Plasmodium_falciparum>.
 * 8) "Plasmodium Falciparum." Wikipedia, the Free Encyclopedia. Web. 15 Nov. 2010. <http://en.wikipedia.org/wiki/Plasmodium_falciparum#cite_note-1>.
 * 9) "Protist: Facts, Discussion Forum, and Encyclopedia Article." AbsoluteAstronomy.com. Web. 15 Nov. 2010. <http://www.absoluteastronomy.com/topics/Protist>.