Page 23 – Biology Notes Online

Gymnosperms – Characteristics, Life Cycle, Examples, Economic Importance

• Last Updated May 3, 2025 • 0 revisions • 27 min readby Sourav Pan

Gymnosperms - Characteristics, Life Cycle, Examples, Importance

Curious about gymnosperms and their role in the plant kingdom? Whether you’re wondering, “Is a pine tree a gymnosperm?” or “What’s the difference between gymnosperms and angiosperms?”, this guide unlocks the answers. Gymnosperms (from the Greek for “naked seeds”) are a group of seed-producing plants that include conifers, cycads, and ginkgos. Unlike angiosperms (flowering plants like the petunia, which is an angiosperm), gymnosperms do not produce … Read more

Gerhardt’s test – Principle, Procedure, Result

• Last Updated May 3, 2025 • 0 revisions • 12 min readby Editorial Team

Gerhardt’s test is a type of laboratory test which is performed for the qualitative detection of ketone bodies in urine.

Seliwanoff’s Test – Principle, Procedure, Result, Uses

• Published on April 21, 2025 • 7 min readby Editorial Team

What is Seliwanoff’s Test? Seliwanoff’s Test is a fundamental biochemical assay designed to distinguish between aldose and ketose sugars based on their structural differences. Named after chemist Theodor Seliwanoff, this test leverages the principle that ketoses (sugars with a ketone group, like fructose) dehydrate more rapidly than aldoses (sugars with an aldehyde group, like glucose) when heated with a … Read more

Cell Organelles – Structure, Functions, Diagram

• Last Updated April 22, 2025 • 0 revisions • 81 min readby Editorial Team

Cell Organelles Structure and their Functions

Your body is currently doing a lot of things simultaneously. Your body is sending electrical impulses, pumping blood and filtering urine.

Gram-Negative Bacteria – Structure, Characteristics, Examples

• Published on April 18, 2025 • 19 min readby Editorial Team

Gram-negative bacteria are a diverse group of microorganisms known for their unique cell structure, which plays a key role in how they interact with the environment and cause infections. Unlike Gram-positive bacteria, Gram-negative bacteria have a thin peptidoglycan layer sandwiched between two membranes. The outer membrane contains lipopolysaccharides (LPS), which can trigger strong immune responses … Read more

Krebs Cycle – Definition, Steps, Products, Regulation

• Last Updated July 30, 2025 • 0 revisions • 11 min readby Sourav Pan

Ever wondered how your cells turn the food you eat into usable energy? Let’s break down the Krebs cycle—a cornerstone of cellular respiration—and answer the questions you’ve been searching for. Also known as the citric acid cycle, this process is a series of chemical reactions that extract energy from nutrients. But where does this critical … Read more

Gram Positive bacteria – Definition, Structure, Characteristics, Examples

• Last Updated April 12, 2025 • 0 revisions • 19 min readby Editorial Team

Gram-positive bacteria are a group of bacteria classified based on how they react to a lab test called the Gram stain. When stained, these bacteria hold onto a purple dye because of their thick, mesh-like cell wall made of peptidoglycan. This sturdy layer acts like a protective shield, unlike Gram-negative bacteria, which have thinner walls … Read more

Tomato Spotted Wilt Virus (TSWV) – Life Cycle, Structure, Symptoms, Vector

• Last Updated July 27, 2025 • 0 revisions • 45 min readby Sourav Pan

Tomato Spotted Wilt Virus (TSWV) - Structure, Symptoms, Management

Tomato Spotted Wilt Virus, often called TSWV for short, is one of those frustrating problems that can really throw a wrench into your gardening plans or hit farmers hard. It’s not just a tomato issue either – this nasty virus has a surprisingly broad appetite, targeting everything from peppers and lettuce to popular flowers like … Read more

Multiphoton Microscopy – Principle, Parts, Steps, Applications

• Published on April 6, 2025 • 15 min readby Sourav Pan

Multiphoton microscopy is a cutting-edge imaging technique widely used in biology and medicine to study living tissues with minimal harm. Instead of relying on single high-energy photons like conventional microscopes, this method harnesses multiple low-energy photons that act together to produce a fluorescent signal. The trick lies in timing—when these photons strike a molecule simultaneously, … Read more

Biological Membrane – Classification, Structure, Functions

• Published on April 3, 2025 • 15 min readby Sourav Pan

Membranes are thin, flexible layers that act like barriers or filters, separating different spaces or substances while allowing certain things to pass through. Think of them as sheets or films—some natural, others human-made. In living things, cell membranes are crucial. They wrap around cells, controlling what enters or exits, like nutrients in and waste out. … Read more