Question

Write a short note on Euglena.

Answer 1

Hint: Euglena is a genus of unicellular eukaryotes. Euglena belongs to the kingdom Protista (Kingdom of unicellular eukaryotes). It is the most famous and best studied member of Euglenoidea. Euglena species was one of the first demonstrations seen under a microscope. These protists have a mixotrophic mode of nutrition.

Complete answer:
Euglena is a demonstration of a single-celled whip protist. The most common species is E. Viridis. It is also found in wet mud. Euglena is a free-living, solitary, single-celled Scourge.
Let’s first of all study about structure of euglena
Structure of euglena:
> It doesn't have cellulose cell walls. The body is covered with a thin flexible membrane.
> The membrane or pellicle has oblique but parallel lines called myonemes. The cuticles are made up of fibrous elastic proteins, small amounts of fat and carbohydrates and retain their shape. Flexible enough to temporarily reshape the body.
> Euglenoids usually have two flagella, one long and one short. Each flagellum originates from an underlying blepharoplast. The apical end has three parts of the intestinal overlap cytopharynx, cytostome and reservoir.
> Chloroplasts are numerous, disc-shaped or tapered. Pyrenoids (protein bodies) may be present in chloroplasts. Chlorophyll a and chlorophyll b are present. There are several mediators in the endoplasmic reticulum. They have a polysaccharide called paramilon. Euglena has been studied in plants and animals. It is called a plant animal.
> Osmoregulation: The contractile vacuoles are involved in osmotic regulation. This expands the liquid content and pumps it into the reservoir.
> Euglena has a mixed diet. The Euglena has both Holophytic and saprozoic nutrition. Like native plants, it absorbs carbon and produces carbohydrates from carbon dioxide and water. This type of Holophytic antelope is found in the presence of sunlight, and the green pigment chlorophyll plays an important role in this.
> Excretion-Carbon dioxide, which is accumulated during breathing during the day, is used for photosynthesis. Unused carbon dioxide is released by diffusion across the body surface. Likewise, nitrogen waste is avoided.
> Reproduction in Euglena : The usual method for reproducing Euglena is longitudinal binary fission. Daughter cells-producers are produced due to symmetric division.

Note:
  Euglena has resemblance with both plants and animals:
> Characteristics of euglena which resembles plants: The presence of chloroplasts with chlorophyll. Holophytic (photosynthetic) diet.
> Characteristics of euglena which resembles animals: Pellicle is composed of non-cellulosic protein. The presence of stigma and parasites (light-sensitive structures). The presence of contractile vacuoles that are not found in plants. The presence of binary longitudinal divisions.