Here's a breakdown:
Key Features:
* Parasitic: Apicomplexans live inside the cells or tissues of other organisms, causing disease.
* Apical Complex: This specialized structure at the anterior end of the cell is composed of organelles like rhoptries, micronemes, and conoids. These organelles play crucial roles in host cell penetration and establishment of infection.
* Non-motile: Most apicomplexans lack flagella or cilia and rely on gliding motility to move within their host.
* Complex Life Cycles: They often have complex life cycles involving multiple host species (often including an invertebrate and a vertebrate host).
Examples:
* Plasmodium: The genus that causes malaria.
* Toxoplasma gondii: Responsible for toxoplasmosis, a common infection in humans that can be particularly dangerous for pregnant women and those with weakened immune systems.
* Cryptosporidium: Causes cryptosporidiosis, a diarrheal illness often associated with contaminated water.
* Babesia: Causes babesiosis, a tick-borne disease similar to malaria.
Impact:
Apicomplexans cause a wide range of diseases, some of which are deadly. They pose a significant threat to human health, particularly in developing countries where access to healthcare is limited.
Research:
Understanding apicomplexan biology is crucial for developing new drugs and vaccines to combat these parasites. Research is ongoing to identify vulnerabilities in their life cycles and develop effective treatments.