Explanation:

Heterotrophic organisms are those organisms which cannot synthesize their own food and depend on other organisms for their nutrition. On the other hand, autotrophic organisms are those which can synthesize their own food.

Euglena:
Euglena is an example of a heterotrophic organism which can synthesize food. It is a unicellular organism which belongs to the phylum Euglenozoa. Euglena has both plant-like and animal-like characteristics. It has a flagellum which it uses for locomotion.

Photosynthesis:
Euglena has chloroplasts which contain a green pigment called chlorophyll. Chlorophyll is responsible for photosynthesis in plants. Euglena can carry out photosynthesis in the presence of sunlight. During photosynthesis, Euglena uses carbon dioxide and water to produce glucose and oxygen.

Phagocytosis:
Euglena can also obtain its nutrition by phagocytosis. Phagocytosis is a process in which Euglena engulfs its food. Euglena can feed on small organisms like bacteria and algae. It can also absorb nutrients from its surroundings.

Conclusion:
Therefore, Euglena is an example of a heterotrophic organism which can synthesize its own food through photosynthesis. It can also obtain its nutrition by phagocytosis. Euglena is a perfect example of an organism which has both plant-like and animal-like characteristics.

Because it depends on others for its food