Whittaker’s Five Kingdom Classification brings evolutionary changes in classification system of organisms. Since the centuries, biologists are trying to classify organisms in different ways. Even, Greek philosopher and polymath Aristotle tried to classify organisms on the basis of their habitats, such as whether they lived on land, water, or air. Then Carolus Linnaeus proposed a
What is Genus? Definition of Genus A genus is a taxonomic rank in biological classification that groups together species with shared characteristics or evolutionary lineage, positioned above species and below family. Classification System The Naming System In the realm of biological taxonomy, the system of binomial nomenclature stands as a cornerstone for naming organisms. This
What is Experimental Group? Definition of Experimental Group The experimental group, in scientific research, refers to the group subjected to specific changes or treatments in a variable to observe and evaluate potential outcomes, in contrast to a control group which remains unaltered or standardized for comparison. How Does an Experimental Group Work? In the context
What is Endosymbiotic Theory? Definition of Endosymbiotic Theory The Endosymbiotic Theory posits that certain organelles in eukaryotic cells, specifically mitochondria and chloroplasts, originated from free-living prokaryotic cells that were engulfed by ancestral eukaryotic cells, leading to a mutually beneficial symbiotic relationship. Origin of the eukaryotic cell 1. Gene Trees and the Complexity of Eukaryotic Origins
What is Domain? Definition of Domain In biology, a domain is the highest taxonomic rank used to categorize and group organisms based on shared characteristics and evolutionary history. Domain in the Tree of Life Development of the Domain System The conception and evolution of the domain system, a fundamental framework for the classification of life,
Three-domain system (Carl Woese’s Classification) explained through its rRNA basis, three domains, key differences, and relationship to kingdom systems.
What is Feedback mechanism? Definition of Feedback mechanism A feedback mechanism is a regulatory system within a process or organism that responds to changes by either amplifying (positive feedback) or counteracting (negative feedback) them to maintain equilibrium or homeostasis. Open and Closed-Loop Feedback Mechanisms Feedback loops are integral components in the maintenance of homeostasis within
What is Motility? Definition of Motility Motility refers to the ability of an organism or cell to move autonomously by utilizing metabolic energy. Types of Motility Motility, a fundamental biological phenomenon, is exhibited through various mechanisms across different organisms. The mechanisms underlying motility are intricate, reflecting the evolutionary adaptations of organisms to their environments. Here,
What is Microorganism? Definition of Microorganism A microorganism, or microbe, is a tiny living organism that is invisible to the naked eye and can exist as single-celled entities or colonies of cells. Discovery of Microorganisms Microorganisms, despite their minuscule size, have had a profound impact on our understanding of life and disease. The journey of
What is Microevolution? Definition of Microevolution Microevolution refers to small-scale changes in allele frequencies within a population over a relatively short period of time, driven by mechanisms such as mutation, selection, gene flow, and genetic drift. Causes of Microevolution 1. Mutation 2. Selection 3. Genetic drift 4. Gene flow Difference between microevolution and macroevolution Microevolution
