Question

Phylum Protozoa

1. Name examples of representative organisms of the Phylum Protozoo and its main characteristics.

2. Name the different types of pseudopods in Amoebas.

3. Name examples of flagellated protozoa.

4. Name examples of ciliated protozoa.

5. Name examples of some pathogenic protozoa.

Answer 1

Answer of question No 1

Protozoans are group of unicellular eukaryotes.Protozoans can be both parasitic or free living. They mostly feed on organic matter (debris or microbes).

Their size ranges from 1 micrometer to several millimeter

They are found abundantly in aquatic habitats (Fresh water or saline).

They are free living, parasitic as well as symbiotic.

they are mostly heterotrophs ( Amoeba) but some can be mixotrophs like Euglena (both autotrophic and heterotrophic).

They move by flagella, cilia or pseudopodia.

they lack cell wall. The cell is covered by membrane like pellicle.

Their life cycle is biphasic. The two phases are the dormant phase (Cyst) and actively dividing phase (Trophozoites)

Example- Amoeba, Paramecium, Trypanosoma.

Question 2.

Pseudopodia are false foots mostly found in Amoeba. They are transitory arm like projections of cell membrane. Pseudopodia remains filled with cytoplasm. It mostly contains actin filaments along with some other intermediary filaments.

Filopodia- pseudopodia with pointed ends, mostly filled with ectoplasm.

Lamellipodia- Flat pseudopodia, mostly involved in locomotion

Lobopodia- contain ectoplasm and endoplasm both. They appear finger like

Axopodia- Narrow pseudopodia, mostly involved in phagocytosis.

Reticulopodia- Individual pseudopodia merge and form net like structure. Primarily involved in food ingestion.

Question 3. Flagellated protozoans move by synchronized movement of flagella.

Examples of flagellated protozoans

Giardia intestinalis- Found in upper small intestine

Trichomonas vaginalis- found in vagina. It causes leukorrhea.

Lophomonas blattarum- symbiotic, helps in digestion of cellulose in intestine of wood roaches.

Leishmania donovani- It causes disease in humans (Dum dum fever)

Trypanosoma gambiense- It causes sleeping sickness.

Question 4- Ciliated protozoans use cilia for motility. The following are examples of ciliated protozoans

Paramecium

Dileptus viridis

Oxytricha trifallax

Didinium

Colpoda

Question 5- Following are pathogenic protozoans

Trypanosoma gambiense- It causes slipping sickness in humans.

Leishmania donovani- It causes dum dum fever.

Plasmodium falciparum- It causes Malaria in humans.

Trichomonas vaginalis- It is found in vagina. It causes leukorrhea.

Giardia intestinalis- It is found in upper small intestine. It causes Giardiasis.