Biology · Biological Classification · NEET
No. This is the most common NEET trap. Euglena does NOT have a cell wall. Instead it has a protein-rich layer called a pellicle just under the cell membrane. Because the pellicle is made of protein (not rigid cellulose), it is flexible, so Euglena can change its shape and move. Remember: pellicle, not cell wall.
The pellicle is a thin, protein-rich layer that lies below the cell membrane and covers the body of Euglena. It replaces the cell wall. Its key property is flexibility, which lets the body bend and change shape. NCERT says the pellicle 'makes their body flexible.'
Neither. Euglena is a Protist. It behaves like a plant in sunlight (it photosynthesises) and like an animal in the dark (it eats smaller organisms). Because it shows both plant-like and animal-like features, biologists could not fit it neatly into Plantae or Animalia, so it is placed in Kingdom Protista.
Mixotrophic means using TWO modes of nutrition. In light, Euglena is autotrophic (makes its own food by photosynthesis). When there is no light, it becomes heterotrophic and feeds on other smaller organisms (holozoic). Doing both = mixotrophic. This is a favourite NEET one-word answer.
Euglenoids are eukaryotic and single-celled, which is the core feature of Protista. Even though their pigments are the same as higher plants and they photosynthesise, they lack a cellulose cell wall and can also eat food like animals. This mixed nature is why NCERT places them in Protista, the group that 'forms a link' between plants, animals and fungi.
Euglena has two flagella: one short and one long. The long flagellum is used for swimming. Do not confuse this with cilia (which Paramoecium has). Flagella = few and long; cilia = many and short.
Yes. NCERT clearly states that 'the pigments of euglenoids are identical to those present in higher plants.' This means they contain the same chlorophyll pigments used for photosynthesis. This exact line is often tested directly in NEET.
Chrysophytes, Euglenoids, Dinoflagellates and Slime moulds are included in the kingdom:
Try the real previous-year questions from this chapter — each with the answer and a full solution.
They are mostly fresh-water single-celled Protists found in stagnant water. They have a protein pellicle (no cell wall), two flagella (one short, one long), are mixotrophic (photosynthetic in light, heterotrophic in dark), and their pigments are identical to those of higher plants. Example: Euglena.
Euglena is the standard NCERT example of a euglenoid. It is the one you should always write in exams.
The majority of euglenoids are fresh-water organisms found in stagnant (still) water, like ponds and ditches.
A cell wall is a rigid outer layer, often made of cellulose (in plants), that keeps the shape fixed. A pellicle is a flexible protein layer in Euglena that lies under the cell membrane and lets the cell change shape. Euglena has a pellicle, not a cell wall.
Euglena shows plant-like features (photosynthesis, plant pigments) and animal-like features (eating other organisms, flexible body, flagellar movement). This mix makes Protista, and Euglena in particular, a link between plants and animals.
