Tag: five kingdoms of living organisms

Noctiluca scintillans belongs to class Flagellata of phylum Protozoa. It is the most common cause of bioluminescence in the ocean. Because of this, it is also called sea sparkle. It produces light throughout the cytoplasm by luciferin- luciferase reaction.

Diatoms are the organisms belonging to Chrysophytes of kingdom Protista. Diatoms occur in all aquatic and moist terrestrial habitats. They may be free floating or bottom dwellers. The free-floating forms remain suspended on the surface of water by mucilage secretion and presence of lightweight lipids. The cell wall is made of silica which is known as frustule. The frustule is made up of two valves, epitheca, and hypotheca. The two valves fit together like a soapbox. They produce auxospores. Auxospore is a rejuvenescent cell which is a zygote grown in size.

When a freshwater protozoan is placed in marine water, the contractile vacuoles disappear. The function of contractile vacuole is to remove the excess water outside by the process of osmoregulation. In marine water, it is necessary to retain the water inside the body instead of out expelling it out. If contractile vacuoles will not disappear, the cell will get dehydrated.

• Euglena is a protist that can both eat food and can photosynthesize. When acting as a heterotroph, the Euglena surrounds a particle of food and consumes it by phagocytosis. When acting as an autotroph, the Euglena utilizes chloroplasts to produce sugars by photosynthesis that's why it is said to be a plant-animal.
• Hence A Protistan which is commonly called plant-animal is Euglena.
• So, the correct answer is 'Euglena'.

(A)Protista are simple eukaryotic organisms that cannot be classified as plant, animal or fungus. They are mostly unicellular, but some are multicellular. They are first originated.