Basic unit of life is cell

Basic unit of Life

 1. Basic unit of life –>The cell in all living organisms. 2. Unicellular organisms are capable of  o (i) independent existence and o (ii) performing the essential functions of life. 3. Anything less than a complete structure of a cell does not ensure independent living. o Cell is fundamental structural & functional unit of all […]



Excretion is a process in which metabolic waste is eliminated from an organism. In vertebrates this is primarily carried out by the lungs, kidneys, and skin.  1. Ammonia, Urea and Uric Acid  ●The major forms of nitrogenous wastes excreted by the animals. Ammonia  ▪︎ most toxic form ▪︎ The process of excreting ammonia is AMMONOTELISM […]

Digestion and absorption


 DIGESTION & ABSORPTION 1. Food –> Carbohydrates, Proteins and Fats. (Have Calorific value) • Vitamins and Minerals (Non calorific value but important) • Food is source of energy –>for growth and repair of tissues. • The water plays an important role in metabolism 2. Biomacromolecules  • Not utilized by body as such so –>Digestion needed […]



EVOLUTION 1.EVOLUTIONARY BIOLOGY is the study of history of life forms on earth. 2.The universe is almost 20 billion years old. 3.The BIG BANG THEORY attempts to explain to us the origin of universe. 4.In the solar system of the milky way galaxy, earth was supposed to have been formed about 4.5 billion years back. 5.There was no […]

Cell cycle and Cell Division


 CELL CYCLE &CELL DIVISION   1. Cell division Very important process in all living organisms –> to maintain continuity of life 2. During the division of a cell —> DNA replication and cell growth take place. 3. Cell division, DNA replication, and Cell growth–> Take place in a coordinated way to ensure correct division and formation […]

Breathing and exchange of gases

Breathing and Exchange of Gases Class 11 Notes CBSE Biology Chapter 17 

1. BREATHING –> Process of exchange of O2 from the atmosphere with CO2 produced by the cells is called breathing, commonly known as respiration. Breathing and exchange of gases ncert pdf 2. Respiration takes place in 3 steps- ●Pulmonary ventilation –> exchange of air between atmosphere and lungs. ●External/pulmonary respiration –>exchange of gases between air […]