Amoeboid Protozoans Locomotion — NEET Biology

Correct answer: B — S1, S2, S3, S4 and S6 are correct

The question tests the understanding of characteristics of different groups within Kingdom Protista. S1: Correct. Diatoms have cell walls embedded with silica, making them indestructible, and they are the chief producers in the oceans. S2: Correct. Dinoflagellates are mostly marine, photosynthetic, have stiff cellulose plates on their outer surface, and possess two flagella, one longitudinal and one transverse. S3: Correct. Euglenoids have a protein-rich pellicle instead of a cell wall, which makes their body flexible. They are photosynthetic in sunlight but behave as heterotrophs by preying on smaller organisms when deprived of sunlight. S4: Correct. Slime moulds are saprophytic protists that form plasmodium under suitable conditions. Their fruiting bodies bear spores with true walls, which are extremely resistant. S5: Incorrect. Amoeboid protozoans live in fresh water, sea water, or moist soil. They move and capture prey using pseudopodia (false feet), not cilia. Marine forms have silica shells on their surface, indicating they are not exclusively marine and some do possess shells. S6: Correct. Ciliated protozoans are aquatic, actively moving organisms due to thousands of cilia. They have a gullet that opens to the outside, and coordinated ciliary movement steers food into it. Therefore, statements S1, S2, S3, S4, and S6 are correct. The tested concept is the distinguishing features of various protistan groups.