Final answer:
The genus Euglena is an example of Euglenophyta, consisting of unicellular aquatic organisms that can function as both autotrophs and heterotrophs due to their ability to photosynthesize and absorb nutrients.
Step-by-step explanation:
An example of Euglenophyta is the genus Euglena, which are unicellular, flagellated organisms found in aquatic environments such as ponds. Euglena species demonstrate interesting characteristics because they are mixotrophs, meaning they can photosynthesize like plants when light is available, due to the presence of chloroplasts. However, in the absence of light, they can also absorb organic nutrients heterotrophically. They are known for their flexibility and movement through water using two flagella and are recognizable by their pellicle, stigma (eyespot), and their photosynthetic capability attributed to their green algal-derived chloroplasts.