Found 122 Articles for Biology Articles

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 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

Introduction Both horses and donkeys are domesticated and also found in wild across the world. Horses usually prefer open areas and like to travel in groups known as herds. For the last many centuries, horses are domesticated by people all over the world. They can live in all most all habitats. Horses have an excellent fight-or-flight response, possessing an excellent trait of fleeing from predators. Donkeys are also known as burros and asses. Both donkeys and horses belong to the same family Equidae. Wild donkeys are found in Deserts and Savannas in Northern Africa, Morroco, Arabian Peninsula, the Middle East, ... Read More

Introduction Hormones are chemical messengers that are secreted in trace amounts by the endocrine cells. They transmit the information from one tissue to another tissue by diffusing it into the bloodstream. The messages transmitted to the target tissue help to control the metabolic and physiological activities in the target cells. A single hormone involves multiple effects on one target tissue or many different tissues. They are predominantly synthesized and released by the endocrine glands including the pituitary gland, adrenal gland, thyroid gland, pancreas, pineal gland, testes, and ovaries, however, they can also be produced and released in the non-endocrine tissues. ... Read More