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Body Fluid And Circulation Notes

  Blood and lymph are the two main body fluids in the human body . Blood comprises plasma, white blood cells, red blood cells and platelets. Lymph comprises lymphocytes. The blood transports nutrients, wastes, and gases throughout the body. Formed Elements  Erythrocytes, leucocytes and platelets are collectively called formed elements (Figure 15.1) and they constitute nearly 45 per cent of the blood. Erythrocytes or red blood cells (RBC) are the most abundant of all the cells in blood. A healthy adult man has, on an average, 5 millions to 5.5 millions of RBCs mm–3 of blood. RBCs are formed in the red bone marrow in the adults. RBCs are devoid of nucleus in most of the mammals and are biconcave in shape. They have a red coloured, iron containing complex protein called haemoglobin, hence the colour and name of these cells. A healthy individual has 12-16 gms of haemoglobin in every 100 ml of blood. These molecules play a significant role in transport of respiratory gases. RBCs ha...
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Breathing and Exchange of Gases Notes

  The "Breathing and Exchange of Gases" chapter, often found in biology textbooks,  explains the process of how organisms, including humans, obtain oxygen and expel carbon dioxide , crucial for cellular respiration and energy production.   Breathing (Pulmonary Ventilation): The mechanical process of moving air in and out of the lungs, involving inspiration (inhaling) and expiration (exhaling).   Respiration: The overall process of gas exchange, including breathing, diffusion of gases across membranes, transport of gases by blood, and cellular respiration where oxygen is used and carbon dioxide is produced.   Respiratory Organs: Specialized organs like lungs (in humans and other vertebrates) or gills (in aquatic animals) facilitate gas exchange.   Mechanism of Breathing: Breathing involves creating pressure gradients between the lungs and the atmosphere, facilitated by muscles like the diaphragm and intercostal muscles.   Cellular Respiration: The proce...
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Biomolecules Notes

  The chapter "Biomolecules"  is about the complex organic molecules found in living organisms, such as carbohydrates, proteins, lipids, and nucleic acids, which are essential for life  Carbohydrates:  Energy source and structural components.     Protein:  Enzymes, antibodies, and structural components.     Lipids:  Energy storage, formation of cell membranes and hormones.     nucleic acids:  DNA and RNA, which store genetic information Biomolecules are essential for the functions of living organisms, such as cell division, metabolic reactions, tissue repair, growth, and other biological processes. Example: Carbohydrates: Glucose, starch, cellulose.     Proteins: insulin, hemoglobin, enzymes.     Lipids: Fats, oils, cholesterol.     Nucleic acids: DNA, RNA. HOW TO ANALYSE CHEMICAL COMPOSITION? We can continue asking in the same way, what type of organic compounds ...
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Structural Organisation in Animals Notes

The "Structural Organisation in Animals" chapter, typically found in Class 11 biology,  explores how cells, tissues, organs, and organ systems are organized to form a complex animal body, focusing on the four main tissue types: epithelial, connective, muscular, and nervous .   ORGAN AND ORGAN SYSTEM  The basic tissues as you have learnt in earlier classes, organise to form organs  which in turn associa to form organ systems in the multicellular organisms.  Such an organisation is essential for more efficient and better coordinated activities  of millions of cells constituting an organism.  FROGS Frogs can live both on land and in freshwater and belong to class  Amphibia of phylum Chordata.  The most common species of frog found in India is Rana tigrina. Morphology Have you ever touched the skin of frog The skin is smooth and slippery due to the presence of mucus.  The skin is always maintained in a moist condition.  The colour of do...
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