Shailesh Koirala 
Introduction Innate immunity is also known as native immunity. It is a resistance with which a person or lower animal is born and is non-specific. This type of immunity is present throughout our life. It may be of various types like species immunity, racial immunity or individual immunity. Various factors like age, hormones, nutrition, etc. … Read more
Introduction The process of ingestion of bacteria or other material by phagocytes and amoeboid protozoans is called phagocytosis. Macrophages and neutrophils show a high capacity for the physical engulfment of particles such as microorganisms or microbial fragments from their immediate extracellular environment. There are other various cells which show this process as well. For engulfing … Read more
Introduction Sterilization is an essential stage which is used in the processing of any product. These products are destined for parenteral administration, or for contact with broken skin, mucosal surfaces, or internal organs where the threat of infection exists. The sterilization of microbiological materials, soiled dressings and other contaminated items is necessary to minimize the … Read more
S.N C3 plants C4 plants 1. The first acceptor of CO2 is ribulose diphosphate (RuDP). The first acceptor of CO2 is phospoenol pyruvate (PEP). 2. Phosphoglyceric acid is the first stable product. Oxaloacetic acid is the first stable product. 3. Calvin cycle is performed by … Read more
INTRODUCTION OF VACCINE Vaccine is a liquid chemical substance, which is used to stimulate an immune response in the body. It contains modified, inactivated or killed pathogens or their antigens. It is administered orally or injected in the body to stimulate the active immunity. Immunity is defined as the ability of a body to resist … Read more
Introduction of Seed The seed is a ripened ovule developed after fertilization. It consists of an embryo and reserve food surrounded by seed coat. The food may be stored in the cotyledons of embryo in non-endospermic or ex-albuminous seeds (e.g.pea, grams, bean) or in a special tissue of seed, called endosperm in endospermic or albuminous … Read more
Introduction of chemical mutagens It is a mutation agent which is a chemical substance that mimic nitrogen base in normal DNA without coupling during DNA replication. Moreover, chemical mutagen has an ability to disturb the DNA replication by inserting themselves between nitrogen bases. There are various types of chemical mutagens. They are as follows: Types … Read more
Introduction to Covalent bond In 1916, G.N Lewis suggested that atoms may combine with one another by mutual sharing of their valence electrons. Due to this, the combining atoms attain the nearest noble gas configuration in their valence cells. These shared pairs of electrons are situated exactly or nearly at the midpoint of the combining … Read more
Introduction It is called as soluble RNA because of its small size made up of 75-95 nucleotides and sedimentation coefficient of mature eukaryotic t-RNA is 3.8 S. There are about 60 different specific t-RNAs in bacterial and 100-110 in mammalian cells. t-RNA is synthesized on a DNA template and is an exception to other cellular … Read more
Introduction Karl Wilhelm von Nägeli in 1842 discovered a thread like structure which was called chromosomes. They are the filamentous bodies typically present in the nucleus and become visible during cell division. They are the carriers of hereditary materials called genes. Most of the chromosomes on a cell are called heterosome and only one to two … Read more