Viruses were first discovered in 1898 by Dutch scientist Martinus Beijerinck. Other Characteristic Features Does not increase in shape and sizeContainsnucleic acid, DNA or RNA as their genetic materialIts genetic material is surrounded by a protein envelope called a capsidReproduces at a much faster rate than bacteria Passes through membrane filters Parts and their Functions A typical virus consists of two basic parts: 1) nucleic acid genome and 2) protein capsid – together called the nucleocapsid....

They were independently discovered by Frederick W. Twort in 1915 and Félix d’Hérelle in 1917. D’Hérelle coined the term ‘bacteriophage,’ meaning ‘bacteria eater.’ Structure of Bacteriophages Types of Bacteriophages Significance of Bacteriophages A T4 bacteriophage consists of the following parts: 1. Head (Capsid) The head of bacteriophages, more commonly known as the capsid, forms the protective casing that encloses the genetic material of the phage. This genetic material is either DNA or RNA, depending on the type of bacteriophage....

Collenchyma was discovered by Scheilden in the year 1839. Strength and Protection: Providing rigidity to the developing plant parts due to polysaccharide deposition in their cell wallSupport: Giving additional back up to the growing plant parts such as stems and leaves to withstand stress Growth: Helping in elongation and development of plantsStorage: Stores defensive antibacterial compounds that protect the plant against bacterial invasion Food Production: Chloroplast containing cells helps the plant to produce food by photosynthesis

The process can be symmetrical, where the daughter cells get an equal share of the mother cell cytoplasm or asymmetrical when the cytoplasm is divided unequally. For example, the process of spermatogenesis in males is symmetrical, producing millions of sperms, all of the equal size. In contrast, oogenesis in females is asymmetrical, producing one large egg cell with mostly mother cell cytoplasm and three small cells called polar bodies. Cytokinesis in eukaryotes hugely resembles the prokaryotic process of binary fission in many ways....

This concept was introduced by French physicist Louis de Broglie in his doctoral thesis in 1924, revolutionizing our understanding of the nature of matter. de Broglie Equation de Broglie Wavelength of Electron Thermal de Broglie Wavelength 1. Planck’s Constant (h) Central to this equation is Planck’s constant, denoted as “h.” Planck’s constant is a fundamental constant of nature, representing the smallest discrete unit of energy in quantum physics. Its value is approximately 6....

Producers are organisms that make their food. Usually, plants and microorganisms are producers. In contrast, consumers feed on producers for their livelihood. Based on their position in the food chain, consumers are divided into primary, secondary, tertiary, and quaternary consumers or apex predators. A desert food chain is unique due to its harsh environment. Desert Food Chain Examples Decomposers The Sahara Desert The Sonoran Desert The Gobi DesertThe Australian Desert Atacama DesertThe Arizona Desert...

Types of Heat Transfer 1. Conduction Heat is transferred between two atoms or molecules in direct contact. The transfer occurs when agitated molecules at high temperatures strike slower molecules at low temperatures, resulting in collisions. Heat transfer occurs through vibrations if the atoms are fixed in a lattice. Conduction takes place in solid, liquid, and gas. For example, when we heat one end of a metal rod, the energy quickly transmits to the other....

The process enhances photosynthesis, increases plant growth, and attracts more pollinators. Thus, helping in the overall development of the plant. Examples of heliotropic plants include sunflower, beans, alfalfa, arctic poppies, and buttercups. In 1832, the Swiss botanist A. P. de Candolle first introduced the term heliotropism, derived from the Greek ‘helios’, meaning sun. Its Types How It Works Heliotropism vs. Phototropism This rapid readjustment of leaves throughout the day is controlled by a specialized organ called the pulvinus....

They are also called half-desmosomes due to their structural resemblance to desmosomes, which are intercellular junctions that hold adjacent cells together. They are also compared to focal adhesion, as they attach cells to the extracellular matrix. However, hemidesmosomes utilize integrins instead of desmogleins and desmocollins in focal adhesions. Structure of Hemidesmosomes Functions of Hemidesmosomes Hemidesmosomes and Associated Diseases Desmosomes vs. Hemidesmosomes The main components of hemidesmosomes are summarized below with their positions in the cell-cell network:...

Formula Permeability of Free Space Relative Permeability Magnetic Permeability Values B represents the magnetic field strength, and H represents the magnetic field intensity. Units The SI unit of magnetic permeability is henry per meter (H/m) or newton per ampere squared (N/A2). One of its most important applications is determining the speed at which electromagnetic waves propagate in free space. The speed of light in a vacuum, denoted by the symbol c, is related to μ₀ and the permittivity of free space (ε₀) through the equation This equation shows that the speed of light depends on the properties of free space, specifically its magnetic permeability and electric permittivity....

The classification of angiosperms was first published by John Ray in 1682 and later by the botanist Antoine Laurent de Jussieu in 1789. Monocots and Dicots Dicots are flowering plants having seeds with two cotyledons or embryonic leaves. They are the largest group within angiosperms consisting of about 200,000 species. Unlike monocots, dicots are not plants arising from a single ancestor but have evolved from different lineages. Thus dicots are paraphyletic....

Why is it Called ‘Oxidative’ Phosphorylation The process is named so, as the conversion of ADP to ATP by adding a phosphate group, is dependent on the oxidative reactions that take place in the mitochondria. The energy released by nutrients during these oxidation reactions is utilized to generate ATP through ETC. Where Does It Take Place Its Steps Total ATP Yield: How Many ATPs are Produced in Oxidative Phosphorylation What is the Purpose of Oxidative Phosphorylation The key steps of this process are as follows: Step 1: Delivery of electrons by NADH and FADH2 In this step, the NADH and FADH2 made in the previous phases of cellular respiration get transformed into NAD+ and FAD, respectively, by donating their electrons in the electron transport chain (ETC)....

The term plasmolysis is derived from the Latin word ‘plasma’ meaning ‘matrix’ and the Greek word ‘lysis’, meaning ‘loosening’. When Does It Occur What Happens in Plasmolysis: Its Process Stages of Plasmolysis in Plant Cell Types of Plasmolysis Do Cells Recover from the State of Plasmolysis Its Importance Examples in Daily Life When a cell is exposed to a hypertonic solution, water starts to flow down its concentration gradient. It thus moves from a region of low solute concentration inside the cell to the high solute concentration in the extracellular fluid....

Surfaces are not always perfectly smooth. Friction arises due to tiny bumps and hills that are present on surfaces. As a result, when one surface comes in contact with another, these bumps interlock and hinder the motion. Because there is no liquid between the surfaces, the phenomenon is also called dry sliding friction. Examples of Sliding Friction Characteristics of Sliding Friction Laws of Sliding Friction How to Calculate Sliding Friction How to Reduce Sliding Friction Sliding and Rolling Friction Rubbing the hands together generates heat due to frictionDifficulty in pushing a fridge on a floorSkidding of a car when trying to brakeSlowing of motion during sledding and skiing...

Why Is Renewable Energy Important What Are the Different Types of Renewable Energy Sources 1. Hydroelectric Energy 2. Wind Energy 3. Solar Energy 4. Biomass 5. Geothermal Energy 6. Ocean Energy 7. Hydrogen Fuel Cells B) To increase energy security: The security of fuel supply is a serious concern worldwide due to rising energy markets and geopolitical uncertainty. So, Countries are relying on their resources to satisfy their power demands. C) Jobs and Economy: The investments in renewable energy infrastructure boost the economy of states and create new job opportunities for youth....

Why are Valence Electrons Important Characteristics of Valence Electrons How to Find Valence Electrons in an Element Representing Valence Electrons Atoms are most stable if they possess a filled valence shell, with each shell having 8 valence electrons. An exception to this phenomenon is hydrogen and helium, which become stable with 2 electrons in their outermost shell. 1. By Using Periodic Table It is the most widely used method to determine the number of valence electrons in an element....

What Makes Fireflies Glow When Do Fireflies Light Up and for What Since the muscles that transport oxygen work slowly, scientists have long wondered how they can blink so fast continuously. Recently it was found that it is nitric oxide that they use to control their glowing, and not oxygen. When there is no nitric oxide present in the body, the oxygen entering their light organ gets bound to the mitochondria (the energy-producing organelles of the cells) and is not available for producing light....

Brayton cycle is named after American engineer George Brayton, who developed and patented a constant pressure engine in 1872. It formed the basis of the gas turbine engine. Theory PV and TS Diagrams Thermal Efficiency Process 1 → 2: Isentropic Compression Fresh ambient air is drawn into the compressor and compressed from pressure P1 to P2. The volume reduces from V1 and V2, and the temperature increases from T1 to T2....

Cell division is responsible for a newborn baby gradually growing into an adult. Similarly, a caterpillar turning into a butterfly. Other living organisms, such as a plant or bacteria, also follow a series of developmental stages following birth until reproduction. Phases of the Cell Cycle Regulation of Cell Cycle Purpose and Importance of the Cell Cycle The process of cell division is more straightforward in lower, single-celled (prokaryotes) organisms than higher multicellular (eukaryotes) ones....