Q.1 Which one of the following protozoan parasites belongs to the phylum Apicomplexa?
(A) Toxoplasma gondii
(B) Leishmania donovani
(C) Entamoeba histolytica
(D) Trichomonas vaginalis
Toxoplasma gondii belongs to the phylum Apicomplexa among the given protozoan parasites. This makes option (A) the correct answer for the question. Detailed analysis of each option confirms this classification based on established taxonomic features.
Option Analysis
Apicomplexa features obligate intracellular parasites with an apical complex for host cell invasion, lacking flagella in most stages.
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(A) Toxoplasma gondii: Classified in phylum Apicomplexa, class Conoidasida; causes toxoplasmosis via tachyzoites and oocysts.
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(B) Leishmania donovani: Belongs to phylum Euglenozoa (or Sarcomastigophora, kinetoplastids); flagellated trypanosomatid causing visceral leishmaniasis.
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(C) Entamoeba histolytica: Phylum Amoebozoa (or Sarcomastigophora, Sarcodina); amoeboid parasite causing amoebic dysentery.
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(D) Trichomonas vaginalis: Phylum Metamonada (or Sarcomastigophora, Zoomastigina); flagellated anaerobe causing trichomoniasis.
The phylum Apicomplexa includes key protozoan parasites like Toxoplasma gondii, vital for CSIR NET Life Sciences preparation. This article solves the MCQ on protozoan parasites phylum Apicomplexa, explaining classifications for exam success.
Apicomplexa Key Traits
Apicomplexa parasites feature an apical complex with rhoptries and micronemes for invasion, mainly intracellular. Examples include Plasmodium (malaria) and Toxoplasma; no flagella in sporozoite stages.
Why Toxoplasma gondii Fits
Toxoplasma gondii, in Apicomplexa, infects cats (definitive hosts) and mammals via oocysts. It causes congenital toxoplasmosis; tachyzoites invade cells using gliding motility.
Other Options Explained
| Parasite | Phylum | Key Features | Disease |
|---|---|---|---|
| Leishmania donovani | Euglenozoa | Flagellated promastigotes; sandfly vector | Visceral leishmaniasis |
| Entamoeba histolytica | Amoebozoa | Pseudopods; cyst/trophozoite forms | Amoebic dysentery |
| Trichomonas vaginalis | Metamonada | Multiple flagella; no cysts | Trichomoniasis |
These lack the apical complex, excluding them from Apicomplexa.
CSIR NET Relevance
Mastering protozoan parasites phylum Apicomplexa aids in questions on parasitology and classification. Focus on apical structures for differentiation.
