Question

Draw a well-labeled diagram of any member of the genus of single-cell flagellate eukaryotes.

Answer 1

They are a genus of single-cell flagellate eukaryotes. It’s the simplest known and most common well-known member of the category Euglenoidea, a various group including some 54 genera and a minimum of 800 species. Species of Euglena are present in freshwater and saltwater.

Complete answer:
Euglena is a free-living unicellular flagellate protist. Euglena contains plastids and function photosynthesis in light but moves around in search of food using its flagellum in the dark. There are around 1000 species of Euglena found. They’re found in freshwater, saltwater, marshes, and also in moist soil. It’s without a cellulose cell membrane. The body is roofed by thin and versatile pellicle. The pellicle has oblique but parallel stripes known as myonemes. Euglena possesses two flagella, generally one long and one short. Each flagellum arises from a basal granule. The apical end bears an invagination that possesses three parts which are cytostome, cytopharynx, and reservoir. An orange-red eyespot or stigma arises jointly to the membrane of the reservoir. An osmoregulatory contractile vacuole takes place within the anterior part of the cell below the reservoir. One large nucleus lies roughly within the middle.

Additional information:
Classification of Euglena is contentious. They’re retained within the phylum Euglenozoa or within the phylum Euglenophyta with algae because of the existence of chlorophyll. Because all the species of Euglena don't include chloroplasts, they're kept within the phylum Euglenozoa. The category Kinetoplastida within the phylum Euglenozoa contains non-photosynthetic flagellates referred to as Trypanosomes, which are parasitic and cause serious diseases in humans like African sleeping sickness, leishmaniasis.

Note:
Many species of Euglena possess photosynthesizing chloroplasts inside the body of the cell, which empower them to nourish through autotrophs (such as plants). However, they will also take nourishment heterotrophically, like animals. Because Euglena possesses features of both animals and plants, early taxonomists, working inside the Linnaean two-kingdom system of biological classification, present them as tough to classify.