RECENT POSTS

• FUNCTIONS OF ENDOPLASMIC RETICULUM
  FUNCTIONS OF ENDOPLASMIC RETICULUM The ER enables the […READ MORE]
• STRUCTURE OF ENDOPLASMIC RETICULUM
  STRUCTURE OF ENDOPLASMIC RETICULUM The endoplasmic […READ MORE]
• ENDOPLASMIC RETICULUM
  Introduction and History Endoplasmic reticulum, the […READ MORE]
• RNA SPLICING
  INTRODUCTION – RNA SPLICING Many of the RNA […READ MORE]
• HARDY WEINBERG EQUILIBRIUM LAW
  The equation derived based on the Hardy Weinberg equilibrium concept is called the Hardy Weinberg law. In this particular equation, p is represented as the dominant allele’s frequency and q is the representation of the recessive allele’s frequency. This is explained with an example to conclude a Hardy Weinberg equation. Consider a single locus with the presence of only two alleles namely A and a. […READ MORE]
• BINOMIAL SYSTEM OF NOMENCLATURE​
  The binomial system classifies organisms into groups at various hierarchic levels, on the basis of easily observable and shared morphological features like shape, number and position of limbs etc. in a descending order of group size. As the word binomial suggests, the name of a species is made up of two parts: one indicating the genus and indicating the species. Binomial nomenclature means “two part name” or “system of two part names”.Which name must be used in case of name conflicts How scientific literature must cite names […READ MORE]
• PLASMODIUM (MALARIAL PARASITE) 
  INTRODUCTION • Plasmodium (Malarial Parasite) […READ MORE]
• KINDS OF ENVIRONMENTAL POLLUTION
  INTRODUCTION Environmental pollution is defined as the […READ MORE]
• BIOTIC FACTORS
  INTRODUCTION Biotic factors and abiotic factors are […READ MORE]
• NOISE POLLUTION
  INTRODUCTION Noise pollution, or noise disturbance, is […READ MORE]
• COMMUNITIES OF THE ENVIRONMENT
  INTRODUCTION All the living organisms of an ecosystem […READ MORE]
• CELLS OF IMMUNE SYSTEM
  INTRODUCTION Cells of immune system and the immune […READ MORE]
• RNA SYNTHESIS
  INTRODUCTION – RNA SYNTHESIS Transcription is, […READ MORE]
• AMINO ACID SYNTHESIS
  INTRODUCTION All amino acids are derived from […READ MORE]
• DE NOVO BIOSYNTHESIS OF NUCLEOTIDE
  INTRODUCTION – BIOSYNTHESIS OF NUCLEOTIDE […READ MORE]
• MECHANISM OF ENZYME CATALYSIS
  INTRODUCTION – MECHANISM OF ENZYME CATALYSIS The […READ MORE]
• PROTEIN SYNTHESIS
  INTRODUCTION – PROTEIN SYNTHESIS Proteins are […READ MORE]
• REGULATION OF ENZYME ACTION
  INTRODUCTION – REGULATION OF ENZYME ACTION The […READ MORE]
• CONCEPT OF FREE ENERGY AND THERMODYNAMICS PRINCIPLES
  CONCEPT OF FREE ENERGY AND THERMODYNAMICS PRINCIPLES […READ MORE]
• CLASSIFICATION OF ENZYMES AND ENZYME KINETIC
  INTRODUCTION CLASSIFICATION OF ENZYMES AND ENZYME […READ MORE]
• ENERGY RICH BONDS, ENERGY TRANSDUCER, ISOMERISM AND RESONANCE
  INTRODUCTION ENERGY RICH BONDS, ENERGY TRANSDUCER, […READ MORE]
• PROTEIN SYNTHESIS REGULATION
  INTRODUCTION PROTEIN SYNTHESIS REGULATION Of the 4,000 […READ MORE]
• BIOSYNTHESIS OF FATTY ACID, CHOLESTROL AND MEMBRANE LIPID
  INTRODUCTION BIOSYNTHESIS OF FATTY ACID, CHOLESTROL […READ MORE]
• CAUSES OF EXTINCTION OF WILDLIFE
  Introduction This article includes comprehensive […READ MORE]
• HIGHER ORDER CHROMATIN STRUCTURE
  INTRODUCTION Higher order chromatin structure […READ MORE]
• MOLECULAR ORGANTIZATION OF EUKARYOTIC CHROMOSOME AND STRUCTURE OF NUCLEOSOME PARTICLES
  INTRODUCTION The large human chromosome of humans […READ MORE]
• ENERGY FLOW IN ENVIRONMENT
  INTRODUCTION Energy flow in environment is the […READ MORE]
• ABIOTIC FACTORS
  INTRODUCTION Abiotic and biotic factors or components […READ MORE]
• ENVIRONMENT AND BIOSPHERE
  INTRODUCTION  Environment and biosphere: Every living […READ MORE]
• TUMOR SUPPRESSOR GENES
  INTRODUCTION Tumor suppressor genes and oncogenes are […READ MORE]
• HUMAN PAPILLOMAVIRUS (HPV)
  INTRODUCTION Human papillomavirus (HPV) infection is […READ MORE]
• AQUATIC ADAPTATIONS IN VERTEBRATES
  Aquatic adaptations occur in those animals which live in water habitat, viz., fresh, brackish or sea water. They are called aquatic animals or hydrocoles. Based upon the phylogenetic history of the aquatic animals, following two types of hydrocoles have been recognised […READ MORE]
• CANCER CELLS VS NORMAL CELLS
  INTRODUCTION Cancer, also called malignancy, is an […READ MORE]
• TERRESTRIAL ADAPTATIONS IN VERTEBRATES
  The idea of adaptation maintains that organisms (animals and plants) are structurally and functionally designed for meeting the needs of life in the habitats in which they live. Thus, adaptations include adjustments by which an organism accommodates itself to its environment. These may occur by natural selection. […READ MORE]
• AERIAL ADAPTATIONS IN VERTEBRATES
  The aerial adaptations are concerned with the flight. The flight is a form of locomotion in the air under which the body has to be firstly prevented from falling down and secondly moved forwards, the speedier the better. Thus, aerial adaptations must include modifications in the animals body for reducing the weight of the body and also for the formation of organs capable of executing the flight. […READ MORE]
• TYPES OF TAXONOMY​ – CHEMOTAXONOMY, CYTOTAXONOMY AND MOLECULAR TAXONOMY​
  TYPES OF TAXONOMY​ -Chemotaxonomy, also called chemosystematics, is to classify and identify organisms according to confirmable differences and similarities in their biochemical compositions. In a nutshell, the biological classification of plants and animals based on similarities and differences in biochemical composition.How scientific literature must cite names […READ MORE]
• TAXONOMIC KEYS​
  A Taxonomic key is a device, which when properly constructed and used, enables a user to identify an organism.In lifesciences, an identification key is a printed or computer-aided device that aids the identification of biological entities, such as plants, animals, fossils, microorganisms, and pollen grains.How names are correctly established in the frame of bionomial nomenclature Which name must be used in case of name conflicts How scientific literature must cite names […READ MORE]
• MODE – DEFINITION AND CALCULATION
  Mode is the value of the variable which occurs most frequently in a distribution. Mode is also positional average which can be located by inspection. […READ MORE]
• AORTIC ARCHES IN VERTEBRATES
  Aortic Arches in Vertebrates Basic embryonic plan. In a typical vertebrates embryo, the major arterial channels include a ventral aorta, a dorsal aorta and usually 6 pairs of aortic arches connecting ventral aorta with the dorsal aorta. […READ MORE]
• GENERAL ACCOUNT OF ELASMOBRANCHII
  The Chondrichthyes, also called elasmobranchii, comprise sharks, rays, skates, chimaeras, etc. Fishes are essentially aquatic and jaw-bearing true vertebrates. This class is specially known for their unimaginable number (about 40,000 species) and bewildering forms. […READ MORE]
• GENERAL ORGANISTION OF GNATHOSTOMATA
  The Gnathostomata includes all vertebrates with upper and lower jaws. It comprises a wide range of animals, from fish to the various tetrapod classes, which have in turn been derived from a fish or fish-like ancestor. An entirely satisfactory classification of fishes is not easy to construct, because of the incompleteness of several parts of the fossil record, and the consequent lack of connecting links. […READ MORE]
• VIRUSES – GENERAL ORGANISATION AND CHARACTERS
  Viruses are very small submicroscopic biological entities which though lack plasma membrane and metabolic machinery. Viruses require some host cell that is they are obligate cellular parasites of either bacteria, plants or animals. There genetic material is can be RNA or DNA. […READ MORE]
• CROSSOPTERYGII :- STRUCTURE AND AFFINITIES
  Crossopterygian, (subclass Crossopterygii), any member of a group of primitive, lobe-finned, bony fishes believed to have given rise to the amphibians and all other land vertebrates.  […READ MORE]
• MEAN – DEFINITION AND CALCULATION
  Arithmetic mean is defined as the quantity obtained by adding together all the given observations and by dividing this total by the number of items. […READ MORE]
• MEDIAN – DEFINITION AND CALCULATION
  Mean, median and mode all three are Central Tendency or Averages. The Arithmetic mean lies under Mathematical Average and the other two Median and Mode are types of Positional Averages. A measure of central tendency is a typical value around which the figures congregate". The value of central tendency or average always lies between the minimum and maximum values. […READ MORE]
• ONCOGENES AND CANCER
  A disease in which cells divide abnormally and destroy body tissues. Three classes of genes are responsible for the onset of cancer. First one is proto oncogene the normally promotes cell growth. After mutation proto-oncogene changes into oncogene whose products are excessively active in growth promotion. […READ MORE]
• HOLOCEPHALI – GENERAL ORGANIZATION AND AFFINITIES​
  Holocephali (Gr. Holos = entire + kephale = head), is a very small ancient group of highly specialized marine fishes. It comprises of rat-tailed fishes. They appeared first in the lower Jurassic and at present, are represented by a few marine genera only. It includes the only cartilaginous fishes having fleshy opercular covering of the gills. […READ MORE]
• AFFINITIES OF DIPNOI​
  With special features of their own, the Dipnoi combine characteristics in which they resemble different groups of fishes as well as Amphibia. AFFINITIES OF DIPNOI​ […READ MORE]
• GENERAL ACCOUNT OF DIPNOI
  The origin and evolution of Dipnoi remains problematic due to diverse opinions. They combine characteristics in which they resemble almost all the other groups of fishes as well as Amphibia. Fossil primitive Dipnoi (e.g. Diptems), shows geater similarity with fossil crossopterygians (e.g. Osteolepis), than do their living members. […READ MORE]
• OSTRACODERMS​ – ORGANISATION AND AFFINITIES
  The earliest known vertebrates to appear in fossil record were jawless primitive fishlike animals collectively known as the ostracoderms, and placed under the class Ostracodermi. They resembled the present day cyclostomes (lampreys and hagfishes) in many respects and together with them, constitute a special group of jawless vertebrates, the Agnatha. […READ MORE]
• SPECIALIZED AND DEGENERATED CHARACTERS OF CYCLOSTOMATES​
  Adult cyclostomes are too specialized or too degenciative in many respect. It is probable that many adult characteristics are adaptations for parasitic mode of feeding. Some of their specialized features are SPECIALIZED AND DEGENERATED CHARACTERS OF CYCLOSTOMATES​ […READ MORE]
• ORIGIN OF CHORDATA​ (PROTOCHORDATA AND EUCHORDATA)
  We shall now consider the origin of the earlier chordate ancestors of vertebrates. That the chordates have originated from the invertebrates is not doubted by most zoologists now-a-days. Since the earlier chordate ancestors were all soft bodied forms, they left no fossil remains to give us clues as to origin of chordata. Therefore, the only basis for judging the origin of the group comes from the resemblances between the lower chordates (protochordates and the invertebrates). […READ MORE]
• INTERNATIONAL CODE OF ZOOLOGICAL NOMENCLATURE​ (ICZN)
  The International Code of Zoological Nomenclature (ICZN or ICZN Code) is a widely accepted convention in zoologythat rules the formal scientific naming of organisms treated as animals. The rules principally regulate: How names are correctly established in the frame of bionomial nomenclature Which name must be used in case of name conflicts How scientific literature must cite names […READ MORE]
• GENETIC POLYMORPHISM
  Polymorphism is most apparent when it affects a visible or behavioral phenotype, but is not at all restricted to such traits. R. Lewontin and J. Hubby, in 1966, undertook the first extensive analysis of protein polymorphisms in natural population of Drosophila pseudoobscura by subjecting extracts of individual flies to get electrophoresis and observing the rates of migration of various proteins, which represented 18 gene loci. […READ MORE]
• MODES OF SPECIATION
  New species form by speciation, in which an ancestral population splits into two or more genetically distinct descendant populations. Speciation involves reproductive isolation of groups within the original population and accumulation of genetic differences between the two groups. […READ MORE]
• SPECIES CONCEPTS (DIFFERENT SPECIES CONCEPTS)
  The categorization and maintenance of species records is important for science and conservation. For identifying an individual species, typically scientists will first consider Biological Species Concept, then descent from common ancestry and genotypic and phenotypic cohesion. Species concepts are still subject to debate. […READ MORE]
• TRENDS IN EVOLUTION
  Evolution is change in the heritable characteristics of biological population over successive generation. Molecular evolution is change in the sequence of molecule of cell. Evolutionary genetics is study where how change in genes leads to change. Molecular markers have ability to detect genetic variation. TRENDS IN EVOLUTION […READ MORE]
• LARVAL FORMS OF ECHINODERMS
  LARVAL FORMS OF ECHINODERMS :- Echinoderm larva is strikingly bilaterally symmetrical in marked contrast to radially symmetrical adult. It swims about by means of a ciliated band, which may be complicated by a number of short or long slender projection or arms from the body wall. Based upon the nature and position of the arms or their absence, lame of different classes of Echinodermata may distinguished. […READ MORE]
• LARVAL FORMS OF MOLLUSCA
  LARVAL FORMS OF MOLLUSCA :- Molluscan life histories do not perfectly correspond with taxonomy, but in general it is true that the archaeogastropods and the bivalves begin life as a trochophore and rapidly pass on to a veliger. There are different types of molluscan larvae according to the importance of the pelegic phase and amount of planktonic food taken. G. Thorson (1950) recognised three ecological types of larvae in Mollusca. […READ MORE]
• LARVAL FORMS OF CRUSTACEA
  LARVAL FORMS OF CRUSTACEA :- Crustaceans show both direct and indirect development. In direct development (e.g„ Palaemon, crayfish), the adult is attained by progressive growth and differentiation of the embryo, so that the newly hatched young resembles the parents in general structure. […READ MORE]
• LARVAL FORMS OF TREMATODA, CESTODA AND ANNELIDA
  LARVAL FORMS OF TREMATODA, CESTODA AND ANNELIDA :- The trematods or flukes are either external or internal parasites, the cestodes or tap worms are internal parasites. The termatoda class includes three order . The fasciola hepatica which is an example of order digenea have mainly 5 larval forms (i) miracidium (ii) sporocyst (ii) redia (iv) Cercaria (v) metacercaria. […READ MORE]
• ADVANCED NERVOUS SYSTEM IN MOLLUSCA​
  Nervous system in mollusca has a well developed nervous system. It also bears paired ganglia, nerves and connectives. One important aspect is there that a Circumentric ring is formed by ganglia. A pair of cerebral ganglia (masses of nerve cell bodies) innervate the head, mouth, and associated sense organs. NERVOUS SYSTEM IN MOLLUSCA​ […READ MORE]
• ADVANCED NERVOUS SYSTEM IN ARTHROPODA​
  NERVOUS SYSTEM IN ARTHROPODA​ is as advance as in Annelida. There is dorsal brain again connected with nerve ring to ventrae nerve cord. The arthropod nervous system consists of a dorsal brain and a ventral, ganglionated longitudinal nerve cord (primitively paired) from which lateral nerves extend in each segment. […READ MORE]
• ADVANCED NERVOUS SYSTEM IN ANNELIDS​
  The advanced nervous system in annelids is generally compare with coelenterates. The well developed nervous system can be seen here in form of a pair of cerebral ganglia (brain) and a double ventral nerve cord. This ventral nerve cord bears ganglia and lateral nerve in each segment as annelids are true segmented animals. […READ MORE]
• PRIMITIVE NERVOUS SYSTEM OF COELENTERATES AND ECHINODERMS
  NERVOUS SYSTEM OF COELENTERATE AND ECHINODERM is not complex.  Hydra and jelly fish possesses diffused nervous system, diffused nervous system is most primitive form of nervous system. Nerve cells are distributed beneath the outer epidermis. Brain is absent though there can be concentrated neuron present locally and ganglia are present. […READ MORE]
• OSMOREGULATION OF FRESHWATER AND MARINE INVERTEBRATES
  Regulation of osmotic pressure of an organism body fluid is refer to as osmoregulation. It allow to maintain balance of water content, fluid content and electrolytes. Hence due to osmoregulation body neither become too dilute nor become too concentrated. Right concentration of solute and amount of water must be maintain by any aquatic [fresh or marine] and terrestrial organisms. It can be mostly achieved by excretion. […READ MORE]
• EXCRETION IN HIGHER TERRESTRIAL INVERTEBRATES
  EXCRETION IN HIGHER TERRESTRIAL INVERTEBRATES :- Excretory system regulates the amount of nitrogenous material, inorganic salts and water content in the blood. Both cockroach and earthworm are terrestrial in habitat their excretion is discuss in detail. […READ MORE]
• EXCRETION IN HIGHER AQUATIC INVERTEBRATES
  EXCRETION IN HIGHER AQUATIC INVERTEBRATES :- Process by which nitrogenous waste produce during metabolism is removed is known as excretion. Some animals such hydra, echinoderms and other may not posses proper excretory organs the reason is quite clear that they are aquatic and it is supposed that nitrogenous material may be diffuse out of there body through their body surface. […READ MORE]
• EXCRETION IN LOWER INVERTEBRATES
  EXCRETION IN LOWER INVERTEBRATES :- Every organism possess different mechanisms, organs and different excretory product. For example porifera and hydra can perform excretion through body surface where as platyhelminthes possess a specialised cells known as flame cells. […READ MORE]
• ORGANS AND MECHANISM OF RESPIRATION IN HIGHER INVERTEBRATES
  ORGANS AND MECHANISM OF RESPIRATION IN HIGHER INVERTEBRATES :- There are generally three common ways through which invertebrates can perform the process  of respiration. These are cutaneous respiration which is mainly performed by lower invertebrates and annelids other is respiration through trachea and gills. […READ MORE]
• ORGANS AND MECHANISM OF RESPIRATION IN LOWER INVERTEBRATES
  ORGANS AND MECHANISM OF RESPIRATION IN LOWER INVERTEBRATES :- In terms of biochemistry respiration is chemical reaction which occur in all living cell that provides energy after breakdown of glucose. Now respiration can be divided into two categories first aerobic respiration and other is anaerobic respiration. […READ MORE]
• PATTERN OF FEEDING AND DIGESTION IN HIGEHER INVERTEBRATES
  PATTERN OF FEEDING AND DIGESTION IN HIGEHER INVERTEBRATES :- There are various mechanism for capturing and feeding over prey or food these are as follow Leeches generally feed over the fluid and soft tissue by piercing and then sucking from their host and simply absorbs the blood from the prey or host […READ MORE]
• PATTERN OF FEEDING AND DIGESTION IN LOWER INVERTEBRATES
  PATTERN OF FEEDING AND DIGESTION IN LOWER INVERTEBRATES :- Every organism needs energy to perform its basic metabolic function. This energy can be obtain from food and sun. As sun is a universal source of energy but only autotrophic organism can obtain energy from sun. […READ MORE]
• ECTOPROCTA – STRUCTURE LIFE HISTORY AND AFFINITIES
  The Ectoprocta are minute, sessile, colonial, unsegmented coelomate animals. Provided by the circular or cresentic lophophore, a u-shaped alimentary canal with anus opening near the mouth but outside of lophophore. Usually posses free swimming larva but without nephridia or circulatory system. […READ MORE]
• ENTOPROCTA – STRUCTURE, LIFE HISTORY AND AFFNITIES
  The Entoprocta or Endoprocta are group of small sessile aquatic animals. In which the body cavity is believed to be pseudocoel. They were formerly include in the phylum Bryozoa which however are true coelomate animals. […READ MORE]
• STRUCTURE, AFFINITY AND LIFE HISTORY OF PHORONIDA
  The Phoronida, brachiopod and Ectoprocta are collectively called as lophophorates coelomates because they all posses lophophore. […READ MORE]
• STRUCUTRE, AFFINITY AND LIFE HISTORY OF ROTIFERA
  The word Rotifera is derived from latin meaning wheel barrier. They are commonly known as “wheel animalcules” as they are rotating wheel like structures […READ MORE]
• HYDROSTATIC MOVEMENT
  Hydrostatic movement occur when dominantly muscles are involved in their movement many organism show such kind of movement including Hydra, Earthworm, Leeches and Echinoderms. […READ MORE]
• LOCOMOTION IN PROTOZOA
  LOCOMOTION IN PROTOZOA :- Moving ones body is an essential need of any organism. Some organism are sessile while other moves at very high speed. Some organisms moves very slowly such as amoeba or euglena where as other can move fastest example leopard. […READ MORE]
• ORGANIZATION OF COELOM
  The word coelom describes the body cavity that is internal space. But there can be difference in coelom true coelom will always be fluid filled lying between outer bodywall and inner digestive tube. It arises between two layers of embryonic mesoderm and consist of most of the visceral organs. […READ MORE]
• THEORIES OF ORIGIN OF METAZOANS
  Metazoans can be define as multicellular organisms or as cellular animal or more accurately simply as animals.They are holozoic multicellular organisms. […READ MORE]