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.

Trochophore Larva – Features, Structure, Metamorphosis, Evolutionary significance

Trochophore Larva

What Is Trochophore Larva? Trochophore larva refers as an early free-swimming stage found by many marine invertebrates like annelids, mollusks, etc. It can define as – a small, spherical or pear-shape larva having a ring of cilia (called prototroch) around its middle part. This larva usually formed after fertilization → from the zygote → and … Read more

Pureline Selection – Procedure, Applications, Advantages, Disadvantages

Pureline Selection

Pureline selection is a method used in plant breeding where plants are chosen from a single self-pollinated variety to create a population that is genetically uniform. It was first introduced by Johannsen (1903) while working with beans (Phaseolus vulgaris). The method based on assumption that variation seen in self-pollinated crops is mostly due to environment … Read more

Post-transcriptional Modification – Definition, Types, Process, Importance

Post-transcriptional modification

Post-transcriptional modification is a set of biological processes common to most eukaryotic cells by which an primary RNA transcript is chemically altered following transcription from a gene to produce a mature, functional RNA molecule that can then leave the nucleus and perform any of a variety of different functions in the cell.

Analytical Balance vs Triple Beam Balance – Key Differences

Difference Between Analytical Balance and Triple Beam Balance

What is Analytical balance? What is Triple beam balance? Difference Between Analytical Balance Vs Triple Beam Balance 1. Precision – Analytical balance gives very high precision (up to 0.0001 g) while triple beam balance only measure till 0.01 g, so less sensitive comparatively. 2. Power Source – Analytical balance mostly works on electric / electronic … Read more

Budding – Process, Types, Advantages, Disadvantages

Budding - Definition, Process, Advantages, Disadvantages

What is Budding? Definition of Budding Budding is a form of asexual reproduction in which a new organism develops from an outgrowth or “bud” on the parent organism, eventually detaching to live independently. Types of Budding I. Types of Biological Budding (Asexual Reproduction) II. Types of Horticultural Budding (Plant Grafting Techniques) 1. Budding in Plants … Read more

Biogeny (Formation of Primitive Life)

Biogeny (Formation of Primitive Life)

What is Biogeny (Formation of Primitive Life)? 1. Formation of nucleic acids and nucleoproteins The formation of nucleic acids and nucleoproteins considered as one of the key transition in Biogeny where information molecules begin to store and transmit life instructions. It started after Chemogeny produced small organic monomers like nucleobases, sugars, phosphates, etc. Prebiotic synthesis … Read more

Polarizing Microscopes – Principle, Parts, Procedure, Uses

Polarizing Microscopes - Principle, Definition, Parts, Applications

What is Polarizing Microscope? Principles of Polarized Light Microscopes The Light Path and Image Formation of Polarized Light Microscopes Parts of a Polarized Light Microscope 1. Light Source – usually a halogen bulb that gives bright white light; it must be stable so the color don’t change by heating or voltage drift. 2. Condenser – … Read more

Nondisjunction – Types, Causes, Consequences, Examples

Nondisjunction - Types, Causes, Consequences, Examples

What is Nondisjunction? Types of Nondisjunction Causes of Nondisjunction Molecular Biology of Nondisjunction Consequences of Nondisjunction The nondisjunction is the failure when chromosomes don’t separate properly during cell division (like meiosis/mitosis), causing abnormal number of chromosomes in daughter cells. Such imbalance is termed as aneuploidy, sometimes loss of one (monosomy 2n–1) or gain of one … Read more

Cleavage – Definition, Types, Planes, Patterns, Significance

Cleavage - Definition, Types, Planes, Patterns, Significance

What is cleavage? Characteristics of cleavage Step by step process of Cleavage Types of cleavages The cleavage pattern in embryos mainly determined by yolk quantity and how that yolk is distributed by the cytoplasm.Also, timing and direction of mitotic spindle (inside egg) play important role. Yolk usually slow / restrict the process of complete division. … Read more

Membrane Filtration Method – Types, Advantages, Disadvantages, Applications

Membrane Filtration Method, Types, Advantages, Disadvantages, Applications.

Membrane Filter Technique can define as a physical separation process, which based mainly on size / molecular weight of particles in a liquid or gas stream. In this method a thin semi-permeable membrane (often made from cellulose nitrate/acetate) is used, and pressure is applied to push the feed solution by it. The smaller components pass … Read more