Answer:
The euglena's red eyespot is used for _____.
Step-by-step explanation:
An Euglena cell with a red eye spot, the eye spot is a photoreceptor organelle found in the flagellated cells of some green algae and other photosynthetic unicellular organisms such as the euglenids.
The ocular spot allows the cells to detect the direction and intensity of the light and respond towards it, or moving away, this allows the cell to search for the optimum amount of light for photosynthesis.
The answer is: Light detection.