Shailesh Koirala 
Introduction They are an integral part of protoplasm and hence are present in every living cell. They account for 14% part of living and 75% part of dead and dried animal body. These are the major components of the body and more important for anabolism than for catabolism. These are compounds of C, H and … Read more
S.N Acraniata Craniata 1. They are exclusively marine. They are aquatic or terrestrial. 2. They are small sized chordates. They are mostly large sized vertebrates. 3. Appendages, cephalization and exoskeleton are absent. Appendages are two pairs usually, well developed head and exoskeleton present. 4. Coelom is enterocoelic, budding off from embryonic archenteron. Coelom is … Read more
Introduction Symmetry means the arrangement of body parts into geometrical designs. Many adult sponges that are irregular in shape are said to be asymmetrical. However, the sponges start their life from a radially symmetrical larva. Four types of symmetry are found in animals. They are: spherical symmetry, radial symmetry, bi-radial symmetry and bilateral symmetry. Spherical … Read more
Introduction to heart sound With each heart-beat, the detectable heart sounds are produced. These sounds represent the auscultatory events of the cardiac cycle. Heart sounds can be amplified and recorded by placing an electronically amplified microphone on the chest. The recording of such sounds is called a phonocardiogram. There are four heart sounds associated with … Read more
Introduction to soil pollution Land and soil are very essential for the survival and maintenance of living organisms including man. Soil supports vegetation on which every living animal depends. However, like air and water, soil may also get polluted. There are many natural and synthetic materials that can adversely affect the physical, chemical and biological … Read more
Introduction Animal inhabiting the aerial environment show many Volant (flying) adaptation for the aerial mode of existence. These animals are known as volant forms. Fishes, amphibians, reptiles, birds and mammals among vertebrates, and insects among invertebrates exhibit volant adaptations. Flight is of two types: i) active or true flight b) passive flight or gliding. A) … Read more
Introduction of Amphibians Amphibians are the first group among the chordates that live outside water. Several new features for terrestrial life also developed in amphibians. Organs of locomotion and protection against desiccation are characteristics. They are not the true land vertebrates though they were the first to emerge from water. Most of the amphibians are … Read more
Introduction to Lymphoid Organs Lymphocytes, which are immature and generated in hematopoiesis gets mature and become committed to a particular antigenic specificity within the primary lymphoid organs. The cell becomes immune-competent only after the lymphocytes have matured in the primary lymphoid organs. T cells arise in the bone marrow and develop in the thymus. In … Read more
Introduction The mammalian ear performs two different and unrelated functions, i.e. hearing and balance. The external and middle ears are involved in hearing only whereas the inner ear functions in both hearing and balancing. Hearing The sound waves from the external source get collected by the pinna. These waves are conducted through the external auditory … Read more
Types of hepatitis A) Hepatitis A It is the inflammation of liver from the hepatitis A virus. HEA virus is generally found in the stools and blood of an infected person about 15- 45 days before symptoms occur and during the first week of illness. Usually spread by fecal-oral contact, or fecal-infected food and water. … Read more