Describe the structure of a trophozoite of Entamoeba histolytica?

Explanation

It is the most active, motile, feeding and pathogenic stage that lives in the mucosa of large intestine. It moves with the help of pseudopodium (lobopodium) which is produced anteriorly. The body of the trophozoite is surrounded by plasmalemma. Its cytoplasm is differentiated into an outer clear, viscous, non-granular ectoplasm and inner fluid like granular, endoplasm. Ribosomes, food vacuoles and-verticular cart wheel shaped nucleus is present. Absence of mitochondria indicates obligate anaerobic nature of Entamoeba histolytica. It produces proteolytic enzyme called histolytica which dissolves mucosas & sub-mucosa of the gut wall & releases blood, tissue debris which are ingested by the trophozoite. Hence food vacuoles are loaded with R.B.C & fragments of cells, bacteria. Presence of R.B.C in food vacuole and cart wheel shaped nucleus are the characteristic features of the trophozoite.