DNA and RNA

DNA and RNA: Genetic Material: The material which stores the biological information in a coded form and is able to transmit such information from one generation to another is called Genetic material. Before the discovery of DNA, proteins were regarded as the genetic material but proteins are unable to replicate like DNA. Hence DNA is described …

Structure of Nephron

Meaning, Number, and Size: A nephron is the structural and functional unit of the kidney. A kidney contains about a million nephrons, each about 3 cm long. There is thus a great surface area for the exchange of materials in a kidney. Structure of Nephron: The body of nephron is differentiated into four regions- Bowman’s Capsule …

Excretory System of Man

Excretory System of Man: The excretory system of man consists of a pair of kidneys, a pair of ureters, a urinary bladder, and a urethra. Kidneys: Appearance and Position: The kidneys are dark red, a bean-shaped organ about 10-13 cm long, 5-6 cm in breadth and 3-4 cm wide, weighing about 150-170 gm in adult male …

Antibiotics

Important Antibiotics & their Uses: The term antibiotic has been derived from the word ‘antibiosis‘ which according to the biology concept means survival of the fittest i.e. a process in which one organism may destroy another to preserve itself. Thus, antibiotics are those chemical substances which are produced by certain micro-organisms such as bacteria, fungi, moulds, …

Applications Of Laser And Maser

Applications of Laser and Maser: LASER stands for Light Amplification by Stimulated Emission of Radiation and MASER stands for Microwave Amplification by Stimulated Emission of Radiation. A LASER is a MASER that works with higher frequency photons in the ultraviolet or visible light spectrum. Properties of Laser: The important features possessed by the laser beam are- …

What are fossils? What do they tell us about the process of evolution?

The dead remains of former living organisms are called fossils. The branch of biology which deals with the study of fossils is called Paleontology. Fossils are the petrified remains of prehistoric animals and plants which have become extinct. The remains or impression of the extinct species left by them in the sedimentary rocks is called fossils …

Lamarckism And Neo-Lamarckism

Lamarckism or Theory of Inheritance of Acquired Characters: The theory of evolution put forward by French biologist Jean Baptiste Lamarck, commonly known as Lamarckism, mainly centers around the inheritance of acquired characters. Characters are acquired by the use and disuse of different organs and evolution is the result of the adaptation of organisms to the environment. …