Flagellum first discovered by Englemann(1887)

Jansen (1887):- report structure of flagellum of sperm.

Hodge (1950):- detailed ultra structure of flagellum of spermatozoa

Manton :-gave ultra-structure of cilia

Cilia and flagella are microscopic, hair or thread like motile structures present extra-cellularly but originate intra-cellularly from the basal body and help in movements, locomotion, feeding, circulation etc.

Central tubules are formed of dynein protein. Peripheral microtubules formed of tubulin

protein Interdoublet linkers formed of nexin protein. Quantitatively it is formed of:-1. Proteins =74-84%2. Lipids=13-23%3. Carbohydrates=1-6%4. Nucleotides=0.2-0.4%

Arise from basal bodies. Similar in ultra structure. Similar chemical composition. Similar in basic function.

Cilia More in number (14,000/

cell).

Small size(5-10 micro meter).

Distributed on whole body

Beat in either metachronous or synchronous coordination.

Sweeping or rowing motion. Locomotion, feeding,

circulation etc are its function.

Flagella Less in number(1-8), but

many in Trichonympha. Large size(150 micro

meter). Located at anterior end of

body. Beat independently.

Undulatory motion. Only locomotion.

Locomotion Cilia of Paramecium and flagella of collar

cells of sponges maintain nutritive-cum-respiratory water current.

Cilia of wind pipe expel out any dust or food particle.

Cilia of kidney-nephrons move nephric filtrate.

Help in conjugation in Paramecium Flagella circulates the food in coelenterons. Cilia of larval forms help in their dispersal.

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