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Phylum- Porifera Introduction:- About 5,000 species of sponges are known. Members of this phylum are commonly known as sponges. They are also known as ‘pore bearers’ as their body walls possess numerous tiny pores. Phylum- Porifera General Characteristic features:- (1) Habitat:- All sponges are aquatic. Most of them are marine but a few sponges live … Read more

kidneys In humans, the excretory system consists  of a pair of kidneys, one pair of ureters, a urinary bladder and a uretha. Shape and Size of Kidneys:-  Kidneys are reddish brown, bean-shaped  structures situated between the levels of  last thoracic and third lumber vertebra close to the dorsal inner wall of the abdominal cavity.  Each … Read more

mitosis Mitosis was first observed by Strasburger in the plant cell and by Walter Flemming in animal cell Theterm mitosis was given by Walter Flemming in 1882. Definition:-  Mitosis is a process in which a parent cell divides into two indentical daughter cells. These cells are indentical to each other as well as to the … Read more

heart sounds During each cardiac cycle two prominent sounds are produced which can be easily heard through a stethoscope. First Heart Sound (LUBB) Second Heart Sound (DUB) 1. It is produced by closing of AV valves (tricuspid valves) during ventricular systole. 1. It is produced by closing of semilunar valves at the beginning of ventricular … Read more

Meiosis (Reductional Division) Definition:- The tem meiosis was coined by Farmar and Moore in 1905. The division was studied by Van Benedin Winiwarter and Strassburger. Meiosis or meio is “to lessen” , hence meiosis is a double division in which a diploid cell form four haploid cells, each having half the number of chromosomes. Meiosis … Read more

muscles INTRODUCTION           Muscles is a  specialized tissue originating from from the mesoderm germ layer. The muscular tissue is made up of specialized cells called myocytes. These cells are bound together by a connective tissue and form muscular tissue. It brings about different types of movements in internal and external body … Read more

lichens Lichens are dual (composites) or entities which contain a permanent association of a fungal partner or mycobiont and an algal partner or mycobiont. Mycobiont is dominant partner and mostly belongs to ascomycetes (Ascolichens- e.g. Graphis, Cladonia, Parmelia, Usnea etc) or sometimes basidiomycetes (Basidiolichens- e.g., Corella, Cora etc). Phycobiont is mostly a member of Chlorophyceae … Read more

respiratory system INTRODUCTION It is a system consisting of respiratory passage and respiratory organs. Respiratory organs are a pair of lungs. Respiratory passage:- It is a passage that takes air from outside to the respiratory surface of lungs. It is consists of a pair of nostrils, nasal cavity, apair of internal nares, pharnx, larynx, trachea, … Read more

KINGDOM: Protista This kingdom formed a link between kingdom Monera on one hand and other three kingdoms i.e. Plantae, Fungi and Animalia on the other hand. Protistians are ancestors of all multicellular eukaryotes (plants, fungi, animals). Kingdom: Protista includes-                                                 Protista                                                     ↓          (1) Autotrophic     (2) Consumer                (3) Protozoans                     or      e.g Dinofagellates    e.g. Cellular slime      … Read more

blood group There are certain molecules on the surfaces of cell in the body that can be recognized as foreign by the immune system of another individual and hence can induce the immune system of latter. These molecules are known as antigens.  As part of the immune response, particular lymphocytes, secretes a class of protein … Read more