Question

Give the characteristics of Protista.

Answer 1

Hint: R.H. Whittaker offered the Five Kingdom classification for living organisms and categorized living organisms on the basis of multiple features. These features are- cellular structure, mode of nutrition, body organization, reproduction, phylogenetic relationship, etc. These five kingdoms contain Monera, Protista, Fungi, Plantae, and Animalia. The term ‘Protista’ is obtained from the Greek word “protistas”. It means “the very first“. Scientists speculate that protists form a link between plants, animals, and fungi.

Complete answer:
The primary characteristic of all protists is, they are eukaryotic organisms. It means they have a membrane-enclosed nucleus. Other characteristics of Kingdom Protista are listed below:
- They are usually aquatic and available in the soil, or in moisture areas.
- They are generally unicellular organisms but also there are a few multicellular protists like kelp. Some species of kelp extend/grow so large that they exceed over 100 feet in height and are called Giant Kelp.
- Just like other eukaryotes, the cells of these species have a nucleus and membrane-bound organelles.
- They are possibly autotrophic or heterotrophic in nature. An autotrophic organism can make its own food and survive. On the other side, a heterotrophic organism has to acquire nutrition from other organisms such as plants or animals to survive.
- We can observe Symbiosis in this class. For example, kelp/seaweed is a multicellular protist that provides otters, protection from predators amidst its thick kelp.
- Protists show locomotion by the cilia and flagella. A few organisms belonging to the kingdom Protista have pseudopodia that help them to move.
- Protista reproduces by asexual means. Sexual reproduction is extremely rare and takes place only during times of stress.

Note: Parasitism is also observed in protists. Species like Trypanosoma protozoa can cause sleeping sickness in humans. Protists are commonly classified into 5 subdivisions based on their general characteristic features. They are classified as Chrysophytes, Dinoflagellates, Euglenoids, Slime molds, and Protozoans. They may be autotrophic or heterotrophic in nature.