Introduction Leprosy is an infectious bacterial disease caused by Mycobacterium leprae. It mainly affects the nerves, skin, eyes, and the upper respiratory tract. Another name for leprosy is Hansen’s disease. Gerhard Armauer Hansen discovered Mycobacterium leprae in 1873 and hence the name Hansen’s disease. If it is not treated on time it causes ulcers in the skin and can damage muscles and nerves that lead to physical disability in the affected individuals. Leprosy mainly occurs in tropical and subtropical climates. Causes of Leprosy Leprosy is an infectious bacterial disease caused by the Mycobacterium leprae. The bacterium is rod-shaped and proliferates ... Read More

Introduction The male reproductive system constitutes different organs with main purpose to produce offsprings so as to continue the species in collaboration with the female reproductive system. A pair of testes, seminal vesicles, the prostate, bulbourethral glands, penis, and a network of excretory ducts or accessory organs constitute the male reproductive system. The different parts of the male reproductive system are described below − Penis − This organ takes part in sexual intercourse. The root, body, and glans are the three parts of the penis. The root is connected with the abdomen wall. The glans is a cone-shaped structure ... Read More

Introduction Leishmania is a parasite of vertebrates belonging to the genus Leishmania and order Trypanosomatida. These infectious parasites are responsible for the vector-borne disease known as leishmaniasis. This disease is transmitted from one person to another with the help of infected sandflies. Leishmania exists in two forms. One is oval and round-shaped and reproduces in the host vertebrate while the other is elongated having flagella and are motile. These are present in the alimentary canal of Sand flies. There are different types of leishmaniasis, namely, cutaneous leishmaniasis, mucocutaneous leishmaniasis, and visceral leishmaniasis. Out of these, cutaneous leishmaniasis is the most ... Read More

Introduction Human anatomy shows that the lower limb or the leg has two parts- the upper leg and the lower leg. The upper leg consists of the thigh that lies between the hip and the knee. The lower leg consists of the calf region that lies between knee and ankle and foot. Legs are anatomically composed of bones (femur, patella, tibia, and fibula) and muscles. Females have shorter femur and tibial length than the males. Legs are used to stand, run, dance, etc. In this tutorial, we will discuss the leg muscles in detail. What are Leg Muscles? Like other ... Read More

Introduction Gregor Johann Mendel (1822-1884) laid the foundation for the development of genetics as we know it today. He performed several monohybrid and dihybrid crosses using seven different qualitative traits of pea plants. What he observed from his rigorous experiments with the pea plant helped deduce the laws of inheritance, which are the basis of heredity for sexually reproducing diploid organisms. Experiments Mendel conducted rigorous hybridization experiments (1856-1863) with the pea plant, Pisum sativum in which he crossed different varieties of pea plants with each other. Mendel chose to work with following characters: Characters Dominant Recessive ... Read More

Introduction Gregor Johann Mendel (1822-1884) known as the “Father of Genetics”, was an Austrian monk. In 1856, he published his work titled ‘Experiments on Plant Hybrids’ in a journal and formulated the laws of inheritance. Mendel carefully carried out certain sets of hybridization experiments using different qualitative traits of pea plants. His study was based on statistical observation from various monohybrid and dihybrid crosses. He discovered that traits are inherited in the form of discrete “factors”. A diploid organism carries two versions of the same factor. Experiments with Pea Plants The experimental subject chosen by Mendel was Pisum sativum, the ... Read More

Introduction Gregor Johann Mendel (1822-1884), an Austrian monk, laid the setting stone in the path to the evolution of genetics as we know it today. His famous hybridization experiments with the pea plant laid the foundations for the laws of inheritance, which are the basis for all sexually reproducing eukaryotic diploid organisms. Mendel carefully carried out certain sets of experiments using different qualitative traits of pea plants and crossed them with each other. He formulated his observations into three principles of inheritance. He discovered that traits are inherited in the form of certain discrete “factors”. A diploid organism carries two ... Read More

Introduction The skin is the body’s outermost layer which functions to protect the body from all sorts of things, including infections, temperature changes, physical, chemical and mechanical stresses, etc. Being the largest organ of the body, the skin of an average adult human spans about 1.5-2.5 metres and is quite thick as well. A square inch of skin contains thousands of nerves, hundreds of sweat glands, and several blood vessels. This makes the skin a highly sensitive and protective organ. Structure of Skin (skin cells and layers) Image Coming soon The skin is a complex organ built on three layers, ... Read More

Introduction With a weight of about 1.5 kg, the liver is the biggest organ within the body and also the largest gland. Accounting for about 2-3% of the body weight, the liver performs various important functions, such as storage of glucose, synthesis of proteins via amino acids, production of bile, removal of toxic wastes, production of blood clotting proteins, cholesterol, etc. Given its indispensable importance in digestion and regulation of the metabolic process, disorders of the liver pose serious threats to healthy bodily functioning. Anatomical Location Anatomically the liver is situated in the abdominal cavity. It occupies the upper right ... Read More

Introduction Clothing is a general term coined for all the various types of materials worn on the body. During ancient times people lived in forests and did not wear clothes. Afterward, to protect the body from different harsh environmental conditions such as heat in summer, cold in winter and rainy seasons, etc., they started wearing clothes. Neanderthals (extinct species and an extremely important part of human evolution) were the first humans who started wearing clothes. In ancient times, humans were not knowledgeable enough to weave clothes and thus used to wear bark, big leaves from trees, animal skin and fur ... Read More