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Also, ammensalism is not a type of predation or parasitism where one species actively benefits at the expense of another. Instead, ammensalism often arises as a side effect of an organism’s activities without any direct intention to harm or help another. Types of Amensalism Examples of Amensalism Importance of Amensalism Amensalism vs. Commensalism 1. Antibiosis The word antibiosis, coined by Vuillemin in 1889-1890, is obtained from the French word ‘antibiosis,’ meaning an antagonistic relationship between organisms....

Functions Basic Structure Types of Anchoring Junctions Stabilizing the position of the cell, providing stability and rigidity, and supporting tissue integrity by holding cell sheets togetherForming a tight seal around the neighboring cells restricting the flow of molecules between cells and from one side of the tissue to the otherRegulating the mobility of the cells and also the tissues in their extracellular matrix through their substrates In addition to transmembrane and intracellular adaptor proteins, some anchoring junctions also contain intracellular signaling proteins that enable the junctions to interact and send signals to the inside of the cell....

Dutch scientist Antonie van Leeuwenhoek first observed bacteria in 1676, using an ordinary microscope. In 1838, the German naturalist Christian Gottfried Ehrenberg called them ‘bacteria’, from the Greek word ‘baktḗria’, meaning ‘little stick’. Later, Robert Koch’s research, famously dubbed ‘Koch’s postulates’, demonstrated that microorganisms such as bacteria cause infectious diseases. Shapes of Bacteria Based on their shape and arrangement, bacteria can be classified into the following four main types:...

Several life forms are found to exist on Earth, from single-celled microorganisms to large, multicellular animals. Although it measures about 20 kilometers (12 miles) from the bottom to the Earth’s surface, most life exists from about 500 meters (1,640 feet) below the ocean’s surface to almost six kilometers (3.75 miles) above sea level. The three main components that make up the biosphere are: The term ‘biosphere’ (‘Bios’ means ‘life’ and ‘sphaira’ means sphere) was coined by geologist Eduard Suess in 1875....

Cell Theory in Timeline The Three Parts of the Cell Theory Modern Cell Theory Why is the Cell Theory Important However, Schleiden’s theory of spontaneous cell formation was later disapproved by Rudolf Virchow in 1855. He instead stated, ‘Omnis cellula e cellula,’ meaning ‘All cells only arise from pre-existing cells.’ which is included as the third part of the cell theory. Thus, combining the contributions of Schleiden, Schwann, and Virchow, the traditional cell theory has three tenets....

It is the principal structural component of plant and algal cell walls. While animals do not produce them, many microorganisms, like bacteria, also make biofilms. Humans cannot digest cellulose as they lack the enzymes that can break down the β-acetal linkages of cellulose. Anselme Payen discovered cellulose from plant matter in 1838 and determined its chemical formula. It was first used to produce the first successful thermoplastic polymer, celluloid. Cotton is the purest natural form of cellulose, consisting of over 90% cellulose....

Unlike parasitism, where one organism benefits at the expense of the other, and mutualism, where both organisms benefit, commensalism involves an unequal partnership. The organism benefiting is the commensal, while the other organism is the host. The term ‘commensalism’ was coined by Pierre-Joseph van Beneden in 1876, obtained from the Latin word ‘commensalis,’ which means ‘sharing a table.’ Types of Commensalism Examples of Commensalism in Nature How Mutualism and Parasitism Differ from Commensalism Brittle stars gain protection and access to food particles brought by water currents Some common examples of commensalism in nature are:...

As the plant matures, the thin epidermal layer (epidermis) is replaced by the periderm. The cork cambium in the periderm helps plants to form new cells that later give rise to inner phelloderm and outer phellem. Thus, unlike the apical meristem tissue in root and shoot tips, cork cambium is a lateral meristem responsible for secondary plant growth. Structure of Cork Cambium in Plants How is Cork Cambium Formed Functions of Cork Cambium Vascular Cambium vs Cork Cambium The cells of the cork cambium show the typical features of meristematic cells but may contain chloroplast....

The order of the bars representing each trophic level is based on which predator feeds on which prey. Energy flows from the bottom toward the top of the pyramid, decreasing as we move up. The height of the bars is the same. However, each bar has a different width based on the units of energy available. Overall, the model represents the amount of energy at each trophic level. It also helps to quantify the energy transfer from one organism to another along the food chain....

It is a triplet code, which means it operates in groups of three nucleotide bases, known as codons. Each codon corresponds to a specific amino acid or a termination signal for protein synthesis. How does a Cell Interpret the Genetic Code How was the Genetic Code Deciphered Characteristics of the Genetic Code Alternative Genetic Code The genetic code is the complete set of messages between codons and amino acids (or stop signals)....

Since luminous flux considers the human eye’s sensitivity, it provides a practical measure of how bright a light source will appear to humans. This makes it a critical parameter in designing lighting for environments such as homes, offices, and public spaces. Unit Applications 1 lm = 1 cd x 1 sr Luminous flux is related to power through the concept of luminous efficacy, which measures how well a light source converts electrical power (in watts) into visible light (in lumens)....

The magnetic response of a material can vary depending on its composition, structure, and temperature. Some materials exhibit high magnetic susceptibility, meaning they can be easily magnetized. In contrast, others may have low or even zero susceptibility. Formula Temperature Dependence of Magnetic Susceptibility Applications Magnetization refers to the amount of magnetic moment per unit volume a material acquires when subjected to an external magnetic field. It depends on the alignment of atomic or molecular magnetic moments within the material....

The term ‘parenchyma’ has originated from the Greek word ‘Para’ which means beside and ‘Enchyma’ meaning inclusion. It was introduced in the 17th century when Robert Hooke discovered the plant cells. Food Production: Chlorenchyma, present in green parts of the plant contains the green pigment, chlorophyll that helps in food production by photosynthesis Storage: Storage parenchyma contains large intercellular space which helps in the storage of starch, water, fats, and oil droplets Transport: Vascular and conjunctive parenchyma helps in the transport of water, nutrients, and other substances throughout the plant Gas exchange: Aerenchyma absorbs carbon dioxide and releases oxygen during the process of photosynthesis and respiration Reproduction: Meristemetic parenchyma divides and give rise to all other cell types and is thus called ‘totipotent’ cellsRegeneration: Meristematic parenchyma retain their ability to divide even on maturity and thus help in regeneration and healing a plant’s wound Strength and Protection: Epidermal parenchyma, present in plant organs helps them to provide mechanical strength and protection from any physical damage...

On Earth, volcanoes are mostly found where tectonic plates are diverging or converging, mostly underwater. Some volcanic eruptions are mild and effusive, while others are highly destructive. What are the Different Parts of a Volcano 1) Magma Reservoir It is a large pool of molten rock found underneath the Earth’s crust. The molten rock remains under extreme pressure, which causes the surrounding rock to crack and fracture, creating an outflow of the magma....

Planck hypothesized that when an oscillator jumps from a higher energy state, E1, to a low energy state, E2, the difference in energy between the two states is proportional to the frequency ν at which the radiation is emitted. Mathematically, the following equation shows how much is one quantum of radiation. ΔE = E2 – E1 = hν Where h is called Planck’s constant, its value is 6.67 x 10-34 J s....

The act of transferring pollen from the anther, the male part of a flower, to the stigma, the female part, is called pollination. For pollination to occur, the plants must be of the same species. How does Pollination Work: Steps of Pollination Agents of Pollination: Pollinators Types of Pollination Why is Pollination Important Step 1: The first step is to transfer pollen from the anther to the stigma of the same or different flower....

The cell membrane is selectively permeable due to its molecular makeup. It allows small, hydrophobic, nonpolar molecules such as carbon dioxide and oxygen to pass easily through their lipid bilayer. In contrast, hydrophilic polar molecules such as water, charged ions such as sodium, potassium, and large molecules such as glucose cannot diffuse simply across them. Such molecules require a carrier protein molecule to assist their transport. They are known as transport proteins....

Factors Affecting Weather Different Types of Weather Conditions There are six main types of weather found on the Earth’s surface. They are: 1. Temperature It indicates how fast air molecules and atoms are moving in the atmosphere. If the atoms are moving fast, the temperature is high, but if they are moving slow, the temperature is low. Temperature thus determines the hotness and coldness of a place, thus affecting the weather....

This law is named after German physicist Wilhelm Wien who derived it in 1893. Formula Wien found that the radiative energy per second per wavelength interval ( \left( \frac{dW}{d\lambda } \right) ) has a maximum at a particular wavelength (λm). The maximum shifts to shorter wavelengths as the temperature (T) is increased. The shift of the maximum is a direct consequence of Planck’s radiation law, which establishes blackbody radiation intensity as a function of wavelength at any given temperature....

Angular acceleration is a vector quantity. It has both magnitude and direction. It is analogous to linear acceleration in translational motion. Unlike linear acceleration, a force is not required for angular acceleration. The skater can accelerate her rotation by contracting her arms. Thus, no external torque is necessary. Angular acceleration is fundamental in understanding rotational dynamics and is crucial in various scientific and engineering applications. Many objects in our daily lives exhibit rotational motion, such as spinning tops, wheels, and planets in orbit....