It is a large phylum that includes parasitic alveolates. Their most unique feature is the presence of apicoplast (non-photosynthetic plastid). Apicomplexa comprises unicellular endoparasites (except Nephromyces). This group includes organisms like gregarines, haemogregarines, piroplasms, coccidia, and plasmodia. They are characterised by spore formation and the motile structure is present only at gamete stages. They have a complex life cycle involving sexual as well as asexual reproduction.
It has secretory organelles that are used to invade the host cells. The secretory organelles include rhoptry, spirally arranged microtubules and electron-dense polar rings. Like any other eukaryote, they have a nucleus, Golgi, and endoplasmic reticulum. They also have a single mitochondrion and a unique apicoplast.
It is a phylum that includes protozoans with hair-like cilia. It is an organelle that is seen in eukaryotes and is identical to flagella. Cilium is a slender protuberance that is used for attachment, swimming, sensation and feeding. The presence of cilia is seen at least once in their life cycle. Ciliophores possess both vegetative and generative nuclei.
Most of them are free-living organisms, while some are opportunistic or obligate parasites. They are found in water bodies and soil. They show both sexual (conjugation) and asexual (fission) reproduction. Examples – Balantidium coli and Paramecium.
Difference between Apicomplexa and Ciliophora
|They are protozoans that have a unique apical complex with apicoplast.||They are protozoans having hair-like cilia.|
|This group includes unicellular endoparasites (except Nephromyces).||Most of them are free-living organisms, while some are opportunistic or obligate parasites.|
|Absence of cilia.||Cilia is present at least once in their lifecycle.|
|Presence of apical complex.||Absence of apical complex.|
|They include gregarines, haemogregarines, piroplasms, coccidia, and plasmodia. Examples – Plasmodium falciparum, Toxoplasma gondii.||Examples – Balantidium coli and Paramecium.|
Also Read: Difference between Cilia and Flagella
Frequently Asked Questions on Difference between Apicomplexa and Ciliophora
What is apicoplast?
The apicoplast is a non-photosynthetic plastid that is mostly present in the phylum Apicomplexa. Most of the apicoplast is ovoid-shaped and is bounded by four membranes. It hosts metabolic pathways like heme biosynthesis, isoprenoid and fatty acid synthesis pathways.
What are alveolates?
The term alveolates include a group of eukaryotic organisms under Protista. Their notable feature is the presence of flattened vesicles called cortical alveoli. These vesicles or sacs are packed in layers, and are bound by a supporting membrane.
What is rhoptry?
It is a specialised club-shaped secretory organelle seen in the apical pole of a few parasites. It is a characteristic feature in the motile stages of phylum Apicomplexa. They have numerous enzymes and proteins that help in host-parasite interaction.
Extended Reading: Protozoa
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