Question

Euglena is autotrophic and heterotrophic both
A. True
B. False

Answer 1

Hint: Euglena has the characteristics of plants and animals as they carry out photosynthesis and can also take nourishment like animals. They exist in water, traveling by means of a flagellum.

Complete answer:
Euglena belongs to the phylum Euglenozoa. These are unicellular organisms which can produce their own food via photosynthesis and also can consume food because they are heterotrophic organisms too.
The Euglenas appear typically green because of the presence of chloroplast but some of the species become red in colour due to carotenoids in large amounts. The colourful euglenas are in large numbers congregating on brackish ponds; it looks like green or red blooms inside water.
When they feed as a heterotroph Euglena takes nutrients by the help of osmotrophy and can live in absence of light on a diet of organic matter.
Whenever there is sunlight it starts feeding by photo trophy which makes the food using chloroplast containing the pigments of chlorophyll a and chlorophyll b to produce sugar by photosynthesis.
Euglena are majority found in the water as it forms a green or red film over top of it as they are good indicators of water pollution.
In the Euglena cell wall is absent and a proteinaceous layer is found called pellicle. The pellicle consists of overlapping and interlocking strips packed in a spiral shape. These pellicular strips give flexibility to the cell. Sliding of these strips with each other leads to the movement of the cell. Because of the strips the cell contracts and manipulates shape.
They have structures such as flagella, eyespot, contractile vacuole and chloroplast. Light sources are used to photosynthesize which are seen with the eyespot.

Hence, the correct answer is option (A).

Note: Structurally they do not have a cell wall so they have a thick outer covering known as pellicle which is composed of protein and gives them strength and flexibility. In the body of the cell, most species of Euglena have photosynthesizing chloroplasts, which enable them to feed like plants through autotrophs. They will, however, also take nutrition heterotrophically, like animals.