Cytoskeleton (CSK): Introduction, Components, Filaments, Protein, Diseases

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Introduction: Cytoskeleton (CSK) is a complex, three-dimensional, dynamic network of interlinking protein filaments found in the cytoplasm of all cells which can be defined simply as “structural frame/ support of cells” (Cyto = Cell + Skeleton = structural support/ frame). It is a complex network of protein filaments or fibres along with motor proteins that […]

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Bacterial Growth Curve: Introduction, Phases, Microbial Growth, Cell count, Cell Mass

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Background: Introduction: Bacterial growth is a complex process that involves both catabolic (breakdown of cell constituents and metabolites) and anabolic (biosynthesis of cell constituents and metabolites) process. Basically, bacterial growth curve is sigmoid shows various recognizable stages of the growth of bacteria- lag phase, log phase or exponential growth phase, stationary phase, and the death

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One-gene-one enzyme hypothesis: Introduction, experiment

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Introduction: In 1946, the relationship between genes and enzymes was first precisely emphasized by George Wells Beadle and Edward Lawrie Tatum which proposed one-gene-one enzyme hypothesis with respect to arginine synthesis. Arginine is a standard amino acid which is biosynthesized through series of biochemical pathway. Three different genes (Gene A, Gene B, and Gene C)

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Extrachromosomal Inheritance: Introduction, Types, Examples

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Introduction: Extrachromosomal Inheritance in eukaryotes: Various scientists have investigated extrachromosomal inheritance in different eukaryotes. Some of the most significant examples of extranuclear inheritance in eukaryotes are as follows: Plastid inheritance Correns and Baur found that the four o’ clock plant, Mirabilis Jalapa, in contrast to other higher plants, contain three types of leaves and parts

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Gene Therapy: Introduction, Types, Methods, Mechanism, Risks, Application

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Introduction: Types: Ex Vivo- The term “ex vivo” means “outside of the living body”.  This technique is a medical procedure that involves removing of cells from the patient followed by genetically modified in a laboratory, using specialized approaches like adding a new gene to the cell or fixing a gene in a cell that is

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Bacterial Toxins: Introduction, Types, Mechanisms of Toxin Action, Symptoms, Treatment, Diagnosis

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Introduction: Types: Exotoxin Fig: Different types of bacterial toxins Endotoxin Endotoxins are the outer parts of the bacterial cell wall especially Gram-ve bacteria such as E. coli, Shigella, Salmonella, Neisseria, Haemophilus Pseudomonas, and other pathogens. Basically, it is released upon cell death, autolysis, phagocytic digestion, and cell lysis which trigger a widespread inflammatory response. Although

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Genetic drift:  Introduction, Types, Roles

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Introduction: Types: The Bottleneck Effect  (Reduction in the population size) Natural occurrences such as deteriorating environmental conditions like natural disaster, flood, earthquake, fires, volcanic eruptions can potentially increase genetic drift. The bottleneck effect occurs when just a few individuals survive, reducing variance in the population’s gene pool. The genetic structure of survivors becomes the genetic

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Neo- Darwinism or Modern Synthetic Theory of evolution: Introduction, Mutation, Genetic recombination, Natural selection, Genetic drift

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Introduction: Darwin’s theory of origin of new species was supported by a number of scientists like Wallance, Haeckel, Weismann, Mendel etc. These supporters are known as the Neo-Darwinians, and the concept is called Neo-Darwinism. The modern synthetic theory explains the genetic basis of the adaptation of a population to new environmental conditions. It includes the

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Darwinism or theory of Natural Selection: Introduction, Facts, Objections

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Introduction: Charles Robert Darwin (1809-1882), an English naturalist publishes his famous book “The Origin of Species by Natural Selection” in 1859. Darwin’s theory of natural selection is based on a mass of accurate observations and prolonged experimental led the whole scientific world to believe on the doctrine of evolution. Darwinism is based on several facts

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Lamarck, Evolution, and the Inheritance of Acquired Characters: Facts, Examples, Criticism

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Theories of organic evolution: Organic evolution refers to the progression of life forms from simpler to more complex as a result of environmental changes and other factors. Evolution describes changes in the shape and behavior of organisms as they pass down through generations. It refers to the changes that occur within a population’s ancestry from

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