Euglena moves by:

Explanation

The question is asking how Euglena moves. Euglena is a microscopic organism that belongs to the group of unicellular protists. There are different ways microorganisms can move and Euglena moves by whipping its flagellum. A flagellum is a long, whip-like appendage that sticks out from the cell body. It helps Euglena to move through the water by propelling it forward. Cilia are also whip-like structures, but they are shorter and more numerous than flagella. They are used by some microorganisms to move, but not by Euglena. Option B is therefore incorrect. Option C suggests that Euglena moves by rotating its flagella, but this is not the case. Euglena moves by whipping its flagellum, not by rotating it. Option C is therefore incorrect. Option D suggests that Euglena moves by pushing out a jet of water from an organelle. While some microorganisms use this mechanism to move, Euglena does not. Euglena moves by whipping its flagellum. Option D is therefore incorrect. Therefore, the correct option is A, which states that Euglena moves by whipping its flagellum.