Fertilization – Definition, Types, Process, and Significance
Learn what fertilization is, its major types, how sperm and egg unite, how polyspermy is controlled, and how fertilization differs in animals, humans, and flowering plants.
Necrosis – Definition, Causes, Mechanism, Types, and Examples
Learn what necrosis is, why it occurs, how cells change, the major patterns of necrosis, key examples, and how necrosis differs from apoptosis.
Antimicrobial Agent and Chemotherapy
Definition of Antimicrobial Agent Antimicrobial agent refers to those chemical or physical agents which are used to kill microorganisms or prevent their growth. There are present several types of microorganism which are responsible for infection or disease in animal or human body such as fungi, bacteria, virus, etc. Similarly, there are present different types of … Read more
Pseudostratified Columnar Epithelium – Definition, Structure, Function, Types
Definition of Pseudostratified columnar epithelium A pseudostratified columnar epithelium an epithelium made up of only one layer of cells which creates the appearance of multiple layers due to the nuclei in the cells are located at various levels. It is histologically an epithelium that is simple, even though when viewed from a cross-section it could … Read more
Signal Transduction Pathway – Steps, Mechanisms, Types and Examples
Learn how signal transduction pathways convert cellular signals into responses through receptors, signaling cascades, phosphorylation, second messengers, amplification, and major pathway examples.
Pathogen Virulence Factors – Types, Mechanisms and Examples
Pathogenicity is the capacity of a microorganism to cause disease in a host. Virulence refers to the intensity or degree of pathogenicity. The virulence varies among different microorganisms and also among strains of same species. Virulence factors are the structures, substances or properties which help a pathogen to cause infection. These factors help the microorganism … Read more
Sandwich (Davson–Danielli) model of cell membrane
Learn the Davson–Danielli sandwich model of the cell membrane, including its structure, evidence, limitations, rejection, and fluid mosaic comparison.
Mesosomes- Definition, Structure, Types, Functions
Learn about mesosomes in bacteria, including their definition, structure, types, proposed functions, NCERT description, and why modern science considers them fixation artifacts.
Inclusion Bodies – Definition, Types, Functions, Examples, and Significance
Learn what inclusion bodies are, their types, functions and examples in bacteria, viruses and cells, including storage granules, viral inclusions and protein inclusion bodies.
Nucleoid – Definition, Structure, Functions, Composition and Diagram
Learn about the nucleoid, its definition, structure, composition, functions, DNA organization, nucleoid-associated proteins, diagram, and nucleoid vs nucleus.