HIV/AIDS virus: Structure, Symptoms, Treatment, Prevention and Mode of Action

Human Immunodeficiency Virus structure

What is HIV/AIDS virus? HIV (Human immunodeficiency virus) is a retrovirus that belongs to the genus Lentivirus, part of the family Retroviridae. It is the causative agent of AIDS (Acquired Immunodeficiency Syndrome).

Phylum Arthropoda: Definition, Characteristics, Classification and Examples

Phylum Arthropoda: Definition, Characteristics, Classification and Examples

Phylum Arthropoda (Gr., arthros = jointed ; podos = foot) is the largest and most diverse group of animals in the animal kingdom, characterized by their segmented bodies, jointed appendages, and exoskeleton made of chitin. This phylum includes insects (e.g., butterflies, beetles), arachnids (e.g., spiders, scorpions), crustaceans (e.g., crabs, lobsters), and myriapods (e.g., centipedes, millipedes). Arthropods play essential ecological roles, such as pollinators, decomposers, and as part of the food web.

Tobacco Mosaic Virus: History, Importance , Structure and Symptoms

Tobacco Mosaic Virus diagram

Tobacco Mosaic Virus (TMV) is a plant virus that mainly infects tobacco plants but can also affect other crops, including tomatoes and peppers. It is a rod-shaped virus, one of the first ever discovered and studied.

Bacteriophages: Definition, Structure, Types and Life cycle

Diagrammatic structure of Bacteriophage

Bacteriophages are the viruses which infect bacteria. These viruses that parasitizes the bacteria. Bacteriophages were discovered independently by Frederick William Twort in 1915 and Félix d’Hérelle in 1917.

Phylum Annelida: Definition, Characteristics, Classification and Examples

Phylum Annelida: Definition, Characteristics, Classification and Examples

Phylum Annelida (L., annelus = little ring or F., anneler = to arrange in rings) is a group of bilaterally symmetrical, coelomate, and segmented animals known commonly as segmented worms. Members of this phylum exhibit a body divided into repeated segments called metameres, which give them structural and functional division. Annelids are triploblastic and possess a true coelom, which is divided by septa, and a closed circulatory system. They have a complete digestive system, a well-developed nervous system with a ventral nerve cord, and excretory structures called nephridia. Respiration occurs through the body surface, gills, or parapodia.

Phylum Aschelminthes: Definition, Characteristics, Classification and Examples

Definition,Characteristics, Classification and Examples of Phylum Aschelminthes

Phylum Aschelminthes (Gr., askes = cavity ; helmins = worm) is a group of bilaterally symmetrical, unsegmented, and pseudocoelomate animals. They are typically characterized by a cylindrical or thread-like body covered with a tough, flexible cuticle. The phylum includes organisms that are predominantly aquatic or parasitic in nature, such as nematodes (roundworms).

Phylum Platyhelminthes: Definition, Characteristics, Classification and Examples

Definition, Characteristics, Classification and Examples of Phylum Platyhelminthes

Phylum Platyhelminthes (Gr., platys = flat ; helmins = worms) refers to a group of invertebrate animals commonly known as flatworms. They are characterized by their soft, unsegmented, dorsoventrally flattened bodies. Members of this phylum are bilaterally symmetrical, triploblastic (having three embryonic germ layers), and acoelomate, meaning they lack a true body cavity. Platyhelminthes exhibit cephalization (a distinct head region) and possess a simple organ system level of organization.

Phylum Ctenophora: Definition, Characteristics, Classification and Examples

Definition, Characteristics, Classification and Examples of Phylum Ctenophora

Phylum Ctenophora (Gr., kestos=comb; phoros=bearing) is a group of marine invertebrates commonly known as comb jellies. These organisms are characterized by their gelatinous bodies, biradial symmetry, and the presence of eight rows of ciliary plates (combs) that they use for locomotion. Unlike jellyfish, which belong to Phylum Cnidaria, ctenophores lack stinging cells (cnidocytes) and instead capture prey using sticky cells called colloblasts.

Viruses: Definition, Characteristics, Morphology and Classification

Structure of Virus labelled Diagram

Viruses are intracellular obligate parasites, non-cellular (acellular) sub-microscopic organisms. The word “virus” means venom or poisonous fluid. They lack cell organelles and make use of the protein synthetic machinery of the host cell.

Coral Reefs: Definition, Types, Formation and Economic Importance

Types of Coral Reefs

Coral colonies grow continuously in size by budding of polyps and often form extensive masses, known as coral reefs.