Avatar for Sourav Pan

Sourav Pan

Founder of Biology Notes Online, Biology & Microbiology Educator, M.Sc. in Microbiology
Expertise
Microbiology, Immunology, Cell Biology, Molecular Biology, Genetics, Biotechnology, Biochemistry, Botany, Zoology
Education
University of Calcutta
Profile Last Updated: August 10, 2026

Sourav Pan is the founder and sole author of Biology Notes Online. He holds a Bachelor of Science (B.Sc.) degree and an M.Sc. in Microbiology from the University of Calcutta. He creates educational resources covering microbiology, immunology, biotechnology, genetics, cell biology, botany, zoology, and other life-science subjects.

His goal is to make complex biological concepts easier to understand through well-structured, student-friendly articles based on academic textbooks, peer-reviewed research, and authoritative scientific sources. In addition to writing new content, he regularly reviews and updates articles to improve their accuracy, clarity, and educational value.

Pathogen Virulence Factors – Types, Mechanisms and Examples

Virulence Factors

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

Sandwich (Davson–Danielli) model of cell membrane

The Davson Danielli model (or the paucimolecular model) was an illustration that depicts the membrane in cells. It was developed in the year 1935 by Hugh Davson and James Danielli The model is a bilayer of phospholipids which is located within two layers of protein globular. the model is trilaminar as well as lipoproteinous.

Inclusion Bodies – Definition, Classification, Examples

Inclusion bodies Definition, Classification, Examples

What are Inclusion Bodies? Inclusion bodies are thick in size, spherical and aggregated proteins typically found inside the cells of protokaryotes thanks to the overexpression of heterologous proteins. Inclusion bodies comprise small particles that are freely suspended and floating in the cell wall. This is why they are also known as inclusions of the cytoplasm. … Read more

Nucleoid – Definition, Functions, Characteristics

Nucleoid - Definition, Functions, Characteristics

The Nucleoid (meaning it’s like a nucleus) is an irregularly-shaped part of the prokaryotic cell which is home to all or most part of the gene material. The chromosome of a protokaryote is circular and its length is big in comparison to cell dimensions, which is why it has to be compressed to be able to fit. Contrary to the nucleus in a prokaryotic cell, it’s not protected by the nuclear membrane.

Cell Signaling – Definition, Types, Functions

Cell Signaling - Definition, Types, Functions

What is Cell Signaling? Three Stages of Cell Signaling Cell signalling can be defined simply as the creation of a “signal” by a single cell. The target cell then receives this signal. In actuality, signal transduction is stated to involve three phases: Types of Cell Signaling Pathways Cell signalling plays a crucial role in enabling … Read more

Transfection – Definition, Types, Principle, Applications

Transfection - Definition, Types, Principle, Applications

Transfection refers to the introduction of foreign DNA (non-host genome genetic material) into a cell. The primary goal of transfection is to modify the host genome in order to express or inhibit the production of the linked protein. The primary purpose of this page is to provide readers with a thorough explanation of the fundamental … Read more