Golgi Apparatus Definition The Golgi apparatus or the Golgi body or Golgi complex or simply Golgi is a cellular organelle present in most of the cells of the eukaryotic organisms. It is referred to as the manufacturing and the shipping center of the cell. … Read more
Cereal grains, such as wheat, corn, rye, oat, rice, etc., are important nutrients and energy sources for humans. Cereal grains are the most commonly consumed food group worldwide and they are grown on about 60% of the cultivated land in … Read more
Cell Wall Definition The cell wall is a rigid and protective layer around the plasma membrane which provides mechanical support to the cell. It is a non-living structure which is formed by the living protoplast. Animal cells do not have a … Read more
Darkfield Microscope Definition Microbiology, the branch of science that has so vastly extended and expanded our knowledge of the living world, owes its existence to Antoni van Leeuwenhoek. In 1673, with the aid of a crude microscope consisting of a … Read more
Centrifugation is a technique of separating substances which involves the application of centrifugal force. The particles are separated from a solution according to their size, shape, density, the viscosity of the medium and rotor speed. Principle of Centrifugation In a solution, particles … Read more
Ctenophora Definition Ctenophores are free-swimming, transparent, jelly-like, soft-bodied, marine animals having biradial symmetry, comb-like ciliary plates for locomotion, the lasso cells but nematocytes are wanting. They are also known as sea walnuts or comb jellies. Phylum Ctenophora Characteristics They are … Read more
What does Biuret test for? Proteins are the complex compound formed by thousands of amino acids. Amino acids are amphoteric electrolytes having carboxyl and amino groups that act like acid and base. It has one positive charge and one negative … Read more
What are Aschelminthes? Aschelminthes are pseudocoelomate, bilaterally symmetrical, triploblastic, unsegmented, vermiform, organ- system grade of construction with complete digestive tubes. Phylum Aschelminthes characteristics They are mostly aquatic, free-living or parasitic. They are bilaterally symmetrical, unsegmented worms. The body is slender, … Read more
Lipids definition Lipids are a heterogeneous group of organic compounds that are insoluble in water and soluble in non-polar organic solvents. They naturally occur in most plants, animals, microorganisms and are used as cell membrane components, energy storage molecules, insulation, … Read more
What is chromatography? Chromatography is an important biophysical technique that enables the separation, identification, and purification of the components of a mixture for qualitative and quantitative analysis. The Russian botanist Mikhail Tswett coined the term chromatography in 1906. The first … Read more
Centrifuge definition A centrifuge is a device used to separate components of a mixture on the basis of their size, density, the viscosity of the medium, and the rotor speed. The centrifuge is commonly used in laboratories for the separation … Read more
Taproot Definition Taproot is one of the two essential root systems where the primary root gives out branches of secondary and tertiary roots growing downwards as the primary root tapers towards the end. The Taproot system is the root system … Read more
Porifera Definition The Porifera may be defined as an asymmetrical or radially symmetrical multicellular organism with a cellular grade of an organization without well- definite tissues and organs; exclusively aquatic; mostly marine, sedentary, solitary or conical animals with body perforated … Read more
Electron microscope definition An electron microscope is a microscope that uses a beam of accelerated electrons as a source of illumination. It is a special type of microscope having a high resolution of images, able to magnify objects in nanometres, which are formed by … Read more
Streak Plate Method- Principle, Methods, Significance, Limitations In microbiology, streaking is a technique used to isolate a pure strain from a single species of microorganism, often bacteria. The dilution or isolation by streaking method was first developed by Loeffler and Gaffky in Koch’s laboratory, which involves … Read more
Spectroscopy is the measurement and interpretation of electromagnetic radiation absorbed or emitted when the molecules or atoms or ions of a sample moves from one energy state to another energy state. UV spectroscopy is type of absorption spectroscopy in which … Read more
Arthropoda (Arthropods) Definition Arthropods are bilaterally symmetrical, triploblastic, metamerically segmented animals with coelom which is reduced and modified. Their body is covered externally in a chitinous exoskeleton which molts periodically and their appendages are joined. Phylum Arthropoda Characteristics They are … Read more
What is a spectrophotometer? A spectrophotometer is an instrument that measures the amount of light absorbed by a sample. Spectrophotometer techniques are mostly used to measure the concentration of solutes in solution by measuring the amount of the light that … Read more
Platyhelminthes (flatworms) definition Platyhelminthes are triploblastic, bilaterally symmetrical, dorsoventrally flattened, acoelomate flatworms with organ grade of construction without a definite anus, circulatory, skeletal or respiratory system but with Protonephridial excretory system and mesenchyme filling the space between the various organ … Read more
Echinodermata (Echinoderms) Definition Echinoderms are enterocoelous coelomates with pentamerous radial symmetry, without distinct head or brain having a calcareous endoskeleton of separate plates or pieces and a peculiar water vascular system of coelomic origin with podia or tube-feet projecting out … Read more
Coelenterata (Cnidaria) Definition The Coelenterata may be defined as diploblastic metazoa with tissue grade of construction having nematocyst and a single gastrovascular cavity or the coelenteron. Phylum Coelenterata (Cnidaria) Characteristics They are aquatic, mostly marine except few freshwater forms like … Read more