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.
What is Prokaryotic Cell? What is Eukaryotic Cell? Difference Between Prokaryotic and Eukaryotic Cells Feature Prokaryotic Eukaryotic Nucleus Absent; genetic material located in a nucleoid region. Present; genetic material enclosed within a nuclear envelope. Membrane-bound organelles Generally absent (e.g., mitochondria, chloroplasts, endoplasmic reticulum, Golgi apparatus). Present (e.g., mitochondria, chloroplasts in photosynthetic cells, endoplasmic reticulum, Golgi … Read more
What is Bright Field Microscope? What is Dark Field Microscope? Difference Between Bright Field Microscope and Dark Field Microscope Feature Bright‑Field Microscope Dark‑Field Microscope Image Background Bright Dark Specimen Appearance Dark/stained specimens appear visible Unstained specimens appear bright against dark Illumination Transmitted white light through specimen Oblique/scattered light; direct light blocked Contrast Mechanism Light absorption … Read more
What is Holobasidium? What is Basidium? What is Phragmobasidium? Difference Between Holobasidium and Phragmobasidium Holobasidium and Phragmobasidium are two distinct types of basidia, which are reproductive structures found in fungi belonging to the division Basidiomycota. These structures play a crucial role in the life cycle of these fungi, particularly in spore production and dispersal. Understanding … Read more
Difference Between Virus and Viroids In this article we will discuss about Differences Between Viroids and Prions. Virus Viroid Difference Between Virus and Viroids – Virus Vs. Viroids Feature Virus Viroid Genetic Material DNA or RNA, single- or double-stranded, linear or segmented Small circular single-stranded RNA molecule Capsid/Coat Protein coat (capsid); some have additional lipid … Read more
What is Southern Blot? What is Western Blot? Southern Blot vs Western Blot Here is a detailed comparison between Southern blotting and Western blotting: Feature Southern Blotting Western Blotting Target Molecule DNA Protein Purpose Detection of specific DNA sequences within a complex DNA sample Detection and analysis of specific proteins in a sample Developed By … Read more
Biodiversity hotspots are regions packed with an extraordinary variety of plant and animal life found nowhere else on Earth—but they’re also in serious trouble. To qualify as a hotspot, an area must have at least 1,500 unique plant species and have already lost over 70% of its original natural habitat due to human activities like … Read more
Funaria is a moss you’ll often find thriving in damp, shady areas like forest floors or along stream banks. Unlike typical plants, it lacks true roots, stems, or leaves, absorbing water and nutrients directly through its surface. If you take a closer look, you’ll spot its vibrant green tufts topped with tiny, capsule-like structures—these hold … Read more
The Beer-Lambert Law is a handy principle used to understand how light interacts with substances, like liquids or gases. Imagine shining a flashlight through a glass of colored water—some of the light gets absorbed, right? This law basically says that the amount of light absorbed depends on three things: how thick the glass is (path … Read more
The Henderson-Hasselbalch equation is a handy formula used in chemistry and biology to estimate the pH of a solution, especially when dealing with buffers—mixtures that resist changes in acidity or alkalinity. Think of it like a cheat sheet for predicting how acidic or basic a solution will be based on the balance between a weak … Read more
