Protista, also known as protozoa or protists, is a diverse group of eukaryotic microorganisms that do not fit into the classification of plants, animals, or fungi. They are mainly single-celled organisms, but some protists are colonial or multicellular. Protista form a kingdom within the domain Eukaryota and display a wide range of forms, structures, and lifestyles.
Here are some key characteristics and features of protists:
Eukaryotic Cells: Protists are composed of eukaryotic cells, meaning they have a true nucleus and other membrane-bound organelles within their cells. This distinguishes them from prokaryotic organisms such as bacteria.
Unicellularity and Multicellularity: Most protists are unicellular, meaning they consist of a single cell that carries out all necessary functions for survival. However, some protists have evolved to form colonies or multicellular structures, where individual cells work together but are not as highly specialized as the cells in complex multicellular organisms.
Diverse Forms and Lifestyles: Protists exhibit a wide range of forms and structures. They can be classified into different groups based on their mode of nutrition and locomotion. Some protists are autotrophs, capable of photosynthesis to produce their own food, while others are heterotrophs and obtain nutrients by consuming other organisms or organic matter. Protists also exhibit various methods of locomotion, such as flagella, cilia, pseudopodia, or simply drifting with water currents.
Habitat and Ecology: Protists inhabit diverse environments, including freshwater and marine ecosystems, soil, and even the bodies of other organisms. They play significant roles in ecological processes, such as nutrient cycling, symbiotic relationships, and as primary producers in aquatic food chains.
Reproduction: Protists reproduce both sexually and asexually. Asexual reproduction methods include binary fission, budding, or fragmentation, where a single cell divides to produce two or more offspring. Sexual reproduction involves the fusion of gametes, which can come from the same or different individuals, resulting in genetic variation.
Ecological and Medical Importance: Some protists have ecological importance as primary producers, contributing to global oxygen production and carbon fixation. Others serve as food sources for larger organisms or as symbionts within other organisms. Certain protists are also responsible for diseases in humans, such as malaria caused by the protist Plasmodium and dysentery caused by the protist Entamoeba histolytica.
It’s important to note that the classification and understanding of protists continue to evolve as new research and discoveries are made. The diverse nature of protists presents a fascinating area of study within the field of biology and highlights the complexity and diversity of life on Earth.
What is Dinoflagellate? Definition of Dinoflagellate Dinoflagellates are single-celled eukaryotic microorganisms, primarily found in marine environments, characterized by two whip-like flagella that facilitate movement. Many species are photosynthetic, and they play vital roles in aquatic ecosystems, ranging from primary producers to causing phenomena like bioluminescence and red tides. Dinoflagellates Classification Dinoflagellates are a diverse group … Read more
What is Phytoplankton? Definition of Phytoplankton Phytoplankton are microscopic, photosynthetic organisms found in aquatic environments that serve as the foundation of marine and freshwater food chains and contribute significantly to global oxygen production and carbon cycling. Characteristics Features of Phytoplankton Phytoplankton are a diverse group of microscopic photosynthetic organisms that inhabit aquatic ecosystems, and they … Read more
What is Kingdom Protista? Definition of Protista Protista: A diverse group of eukaryotic microorganisms, not belonging to animals, plants, or fungi Protists The scientific name of protists Amoeba Amoeba proteus Paramecium Paramecium pentaurelia Stentor Stentor coeruleus Euglena Euglena gracilis Volvox Colonial volvox Slime mold Physarum polycephalum How do they Look? – Protista Under Microscope History … Read more
Phylum Nemathelminthes General Characteristics of Nemathelminthes Phylum Nemathelminthes, also known as Nematoda or roundworms, exhibit several general characteristics that define their biology and classification. Here are some key characteristics of nematodes: Structure of Nemathelminthes Nemathelminthes, also known as roundworms or nematodes, exhibit a unique structure that distinguishes them within the animal kingdom. Here are the … Read more
What is Corals and coral Reefs? Structure of coral Polyp Structure of coral skeleton Coral created by a single Polyp is known as corallite. A collection of colonial Polyps that create the skeletal mass known as corallum. The base of each corallite is known as the basal plate. Theca encompasses the aboral region of Polyp. … Read more
What is Polymorphism in cnidarians? The majority of polyps are sessile, whereas meduase types are motile. Nonetheless, there is a similarity between the two in their fundamental characteristics. Importance of Polymorphism Polymorphism is fundamentally a phenomena of labour division. Rather than assigning diverse functions to the components or organs of a single individual, distinct functions … Read more
Sea fur is an alternative term for Obelia. Obelia has a delicate, semitransparent, pale to light-brown hydroid colony. It consists of stems with vertical branches called hydrocauli and root-like branches called hydrorhiza. In order to complete its life cycle, Obelia’s asexual and sexual generations alternate. The life cycle of Obelia regularly alternates between hydroid and … Read more
Cnidaria comes from the Greek word cnidos, which means stinging thread. The existence of cnidae characterises these creatures. Cnidaria is a phylum within the Kingdom Animalia that contains 10,000 known species, including corals, sea anemones, jellyfishes, and hydras. These organisms are found in both marine and freshwater environments. It is an additional ancient group with … Read more
What is Protista? – Protista Definition Different Locomotion organs of Protista Protists are a heterogeneous group of unicellular eukaryotic creatures with a vast array of movement techniques. Certain protists utilise flagella, cilia, or pseudopodia for locomotion. 1. Flagella Some protists have long, whip-like appendages called flagella that protrude from their surface. They are utilised for … Read more
Protists are a varied category of eukaryotic creatures that are unicellular or multicellular, and can be free-living or parasitic. They have a simple cellular structure, with a nucleus and other membrane-bound organelles, and are capable of a wide variety of metabolic operations, including as photosynthesis, digesting, and locomotion. Protists are found in nearly all habitats … Read more
Reproduction in Protista Methods of Reproduction in Protists The following paragraphs emphasise the two essential reproductive strategies of protists. The procedures are: A. Asexual Reproduction in Protists Mode of Asexual Reproduction In Protista 1. Binary Fission Mitosis is the division of the parent cell into two identical daughter cells. Examples: Amoeba, Euglena and Paramecium. 2. … Read more
Origin of Parazoa Choanoflagellate: Link to sponges Sponges’ internal chambers are bordered by a series of specialised cells known as choanocytes (choano = collar; cyte =cell). These are the cells that feed sponges. Each choanocyte, like choanoflagellates, possesses a collar of tentacles enclosing a single anterior flagellum. By undulating dozens of flagella, choanocytes generate a … Read more
What is Phylum Porifera? – Definition of Phylum Porifera Phylum Porifera refers to a group of simple, sessile aquatic animals commonly known as sponges. Sponges lack true tissues and organs and have a porous body structure with numerous channels and chambers that allow water to flow through them. They feed by filtering small particles from … Read more
The water circulation system of sponges, also known as canal system, is the defining property of the phylum Porifera. The system of canals is also known as the auriferous system. The sponge canal system aids in food uptake, respiratory gas exchange, and excretion. Many pores on the body surface of sponges allow for the admission … Read more
The marine invertebrate phylum Ctenophora, often known as comb jellies, is widespread throughout the world’s oceans. Their transparent, gelatinous bodies are comprised of eight rows of cilia, or comb-like structures, which they employ for swimming and collecting prey. Ctenophores, unlike jellyfish, lack stinging cells, or nematocysts. Instead, they utilise colloblasts, or sticky cells, to capture … Read more
Phylum Platyhelminthes Flatworms, or the Phylum Platyhelminthes, are a group of soft-bodied, bilateral, flattened from top to bottom invertebrates. They are found in marine, freshwater, and terrestrial settings. Flatworms are frequently hermaphroditic and lack a coelom (body cavity) and circulatory system (possessing both male and female reproductive organs). They differ in size from microscopic to … Read more
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