Class 12 Biology Notes for FBISE (With FREE PDF)

• Human respiratory system
• The human respiratory system is a gas exchange system that delivers oxygen to the body and removes carbon dioxide. It is made up of the nose, pharynx, larynx, trachea, bronchi and lungs. The air passages of the respiratory system are lined with mucus membranes that trap inhaled particles and pollutants, such as dust and pollen.
• Mucus membranes are also coated with cilia that are constantly moving, pushing contaminants out of the lungs as it moves up to the throat. The trachea branches into two bronchi that distribute air to each lung. Within each lung, there are smaller bronchi called bronchioles that divide into alveoli where gas exchange occurs between capillaries and air sacs.
• The mucous membranes in the lungs trap particulates in the air we breathe in while cilia move mucus out of our mouth and nose. Finally, exhaling expels carbon dioxide from our bodies.
• It also removes carbon dioxide, which forms as a waste product from chemical reactions in the cells, from the blood and releases it into the environment. There are three major parts of the respiratory system:
• -Airways: tubes that carry air in and out of the lungs
• -Respiratory muscles: muscles that help with breathing
• -Alveoli: tiny air sacs where oxygen exchange takes place
• Control of  Breathing
• Respiratory disorders
• Mechanism of transport of disorders
• Lung volumes and capacities
• Much more!

Chapter 15 – Homeostasis

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Chapter 23 – Chromosome and DNA

Chapter 24 – Evolution

Chapter 25 -Man and Environment

Chapter 26 -Biotechnology

Chapter 27 -Biology and Human Welfare