APICOMPLEXANS Meaning and
Definition
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Apicomplexans are a diverse group of intracellular parasites belonging to the phylum Apicomplexa. They are characterized by the presence of a unique structure called an apical complex, which consists of specialized proteins and organelles located at one end of their cells. This complex allows apicomplexans to invade and occupy host cells, where they establish a parasitic relationship.
Apicomplexans have a complex life cycle, typically alternating between sexual and asexual stages. They possess both a definitive host, where sexual reproduction takes place, and one or more intermediate hosts, where asexual reproduction occurs. The definitive host is usually a vertebrate, while the intermediate host is often a different animal or an invertebrate.
Many apicomplexans are pathogenic and can cause diseases in both humans and animals. Well-known examples include the parasites responsible for malaria (Plasmodium spp.), toxoplasmosis (Toxoplasma gondii), and coccidiosis (Eimeria spp.). These organisms are of significant medical and veterinary importance due to their ability to cause severe morbidity and mortality.
Apicomplexans are characterized by their ability to invade and replicate within host cells, utilizing various mechanisms to subvert the immune response and establish chronic infections. They possess specialized organelles called rhoptries, micronemes, and dense granules, which play crucial roles in host cell recognition, invasion, and nutrient acquisition.
Overall, apicomplexans are a diverse and medically important group of parasites with complex life cycles and unique cellular structures. Extensive research is ongoing to understand their biology and develop effective strategies for prevention and treatment of the diseases they cause.
Etymology of APICOMPLEXANS
The word "apicomplexans" is derived from the Latin word "apex", meaning "tip" or "peak", and the Greek word "complexus", meaning "twisted together". It refers to a group of protozoan parasites that possess a specialized structure called the apical complex, which is located at the apex (tip) of their cells. The apical complex enables these organisms to invade host cells and establish infection. Thus, the term "apicomplexans" describes their unique structural feature.
