Biology

Water, Our Lifeline * Increase in population, industrialisation and improper disposal of wastes results in water pollution. This, in turn results in the scarcity of clean water. * The United Nations has declared the period 2005- 2015 as the International Decade for Action “Water for Life”. * Contaminated water causes many water – related diseases. ... Read more

Solid Wastes * A sanitary landfill is a place where municipal solid wastes are compacted and dumped in a depression or trench. * Solid wastes include item such as paper, food wastes, plastics, glands metals, rubber, leather and textiles. * Solid wastes must be segregated into three categories: recyclable, biodegradable and non – biodegradable. * ... Read more

Micro Organisms: Friend and Foe – Dealing with Harmful Micro Organisms * Micro organisms are not visible to the naked eye. * Some microbes, called pathogens, cause serious diseases like dysentery, malaria, cholera, typhoid, polio and many others. * Microbes are used as antibiotic and vaccinating agents medicinally.

Transmission of Diseases * Air, water, food, physical contact and vectors are means of transmission of infection disease. * Prevention of diseases is more desirable that it’s successful treatment. * Availability of proper and sufficient food for everybody is a basic principle of prevention of infectious diseases. * Immunization is another way to prevent infectious ... Read more

Why Do We Fall Ill – Diseases * Health is a state of physical, mental and social well being. * Disease is an unhealthy condition caused by micro organisms, improper diet or is inherited. * Bacteria cause disease like typoid, cholera, tuberculosis and anthrax. * Viruses cause the common cold, influenza, dengue fever, AIDS and ... Read more

Life Processes – Respiration * Respiration is the process of oxidation of food and releasing energy. * Breathing is the process o f inhaling oxygen and exhaling carbon dioxide. * Exhaled air contains more carbon dioxide than when compared to atmospheric air. * Aerobic organisms break down their food into carbon dioxide and water while ... Read more

Integumentary System * The integumentary system is the largest is the largest organ system accounting for about 16% of the total body weight. * The integumentary system consists mainly of the skin and its soft derivatives like sweat glands, sebaceous glands and mammary derivatives like hair and nails. * The skin is made up of ... Read more

Body Movement – Joints and Their Types * Bones are joined together at places called joints and help in body movements. * Different animals use to different body parts for movement. * Each body part is capable of different movement, and is hence controlled by different types of joints. * Ball and socket joints allow ... Read more