NCERT Class 11 Biology Chemical Coordination and Integration Important Notes
ENDOCRINE GLANDS AND HORMONES Endocrine glands lack ducts and are hence, called ductless glands. Their secretions are called hormones. Hormones: Hormones are non-nutrient chemicals which act as intercellular messengers and are produced in trace amounts. HUMAN ENDOCRINE SYSTEM…
NCERT Class 11 Biology Nervous Control and Coordination Important Notes
Nervous System:- The nervous system of all animals is composed of highly specialised cells called neurons which can detect, receive and transmit different kinds of stimuli. HUMAN NERVOUS SYSTEM :- The human nervous system is divided into two parts: (i) Central Nervous…
NCERT Class 11 Biology Locomotion and Movement Important Notes
TYPES OF MOVEMENT Cells of the human body exhibit three main types of movements, namely, amoeboid, ciliary and muscular. Amoeboid Movement:- Some specialised cells in our body like macrophages and leucocytes in blood exhibit amoeboid movement. It is effected by pseudopodia…
NCERT Class 11 Biology Excretory Products and their Elimination Important Notes
Animals accumulate ammonia, urea, uric acid, carbon dioxide, water and ions like Na+, K+, Cl–, phosphate, sulphate, etc., either by metabolic activities or by other means like excess ingestion. These substances have to be removed totally or partially. The process of removal of…
NCERT Class 11 Biology Body Fluids and Circulartion Important Notes
Blood: Blood is a connective tissue which is composed of a fluid matrix (plasma) and formed elements. Plasma Plasma is a straw-coloured and viscous fluid. Plasma constitutes about 55% of the blood. About 90% of plasma is water and about 6-8% is composed of proteins. The…
NCERT Class 11 Biology Breathing and Exchange of Gases Important Notes
Respiration: The process of exchange of O2 (from the atmosphere) with CO2 (produced by cells) is called breathing. This process is commonly known as respiration. Respiratory Organs: • Mechanisms of breathing vary among different animal groups. It usually depends on the…
NCERT Class 11 Biology Digestion and Absorption Important Notes
Food: Food is a basic requirement of all living beings. Food provides energy for different activities in the body. Food also provides organic materials for growth and repair. Carbohydrates, proteins and fats are the major components of food and hence these are called…
NCERT Class 11 Biology Plant Growth and Development Important Notes
Growth: A permanent and irreversible increase in size of an organ or its part or even of an individual cell is called growth. Growth is usually accompanied by metabolic process; which occur at the expense of energy. Indeterminate Nature of Plant Growth: Plants retain the…
NCERT Class 11 Biology Respiration in Plants Important Notes
Exchange of Gases in Plants: Plants do not have great demands for gaseous exchange. The rate of respiration in plants is much lower than in animals. Large amounts of gases are exchanged only during photosynthesis, and leaves are well equipped for that. The distance travelled…
NCERT Class 11 Biology Photosynthesis in Higher Plants Important Notes
Photosynthesis is a process in which the plants use light energy to make carbohydrate from carbon dioxide and water. The overall reaction of photosynthesis can be given in a simple form as follows: In green plants, water is the hydrogen donor and it undergoes oxidation to…
NCERT Class 11 Biology Mineral Nutrition Important Notes
Criteria for Essentiality • The element is absolutely necessary for supporting normal growth and reproduction. • In the absence of essential elements, plants cannot complete their life cycle or set the seeds. • The essential element must be specific and is not replaceable…
NCERT Class 11 Biology Transport in Plants Important Notes
Diffusion: When molecules move from higher concentration to lower concentration in a random manner, the movement is called diffusion. The movement of substances through diffusion is a passive transport. Diffusion is a slow process and is not dependent on a ‘living’ system.…
NCERT Class 11 Biology Cell Cycle and Cell Division Important Notes
Phases of Cell Cycle The cell cycle is divided into two basic phases: a. Interphase: The phase between subsequent cell divisions is called the interphase. The interphase lasts for more than 95% of the cell cycle. b. M Phase (Mitosis phase): The actual cell division takes…
NCERT Class 11 Biology Biomolecules Important Notes
Analysis Of Chemical Composition: For this, a living tissue is taken. The tissue is ground in trichloroacetic acid (Cl3CCOOH); by using pestle and mortar. The slurry is then filtered through a cloth. The filtrate contains acid-soluble pool and the retentate contains acid-…
NCERT Class 11 Biology Cell The Unit of Life Important Notes
Unicellular organisms are capable of independent existence and they can perform the essential functions of life. Anything less than a complete cell does not ensure independent living. Hence, cell is called the fundamental structural and functional unit of life. CELL THEORY…