Ciliates differ from all other protozoans in

What is the importance of diatoms?

Passive food ingestion in $Amoeba$ is known as

Which of the following organelles are associated with defence in protozoans?

Two species of Amoeba $X$ and $Y$ were kept in fresh water and adapted to it. Species $X$ developed a contractile vacuole. When both were transferred to sea water and adapted, both $X$ and $Y$ lost their contractile vacuole. From these observations, we conclude that:

Which of the following organisms uses light energy for the synthesis of $ATP$ via bacteriorhodopsin?