Kerala SSLC Biology Chapter 4 Notes Keeping Diseases Away English Medium
In order to maintain homeostasis, organisms keep their internal environment free from wastes. We are highly concerned about personal hygiene, but many of us do not give adequate attention to community hygiene. We conserve our external environment for the well being of nature and its countless species of living beings. This unit mainly deals with various types of diseases which adversely affect the health of a person.
→ Communicable diseases : Diseases caused by the invasion of pathogens into the body and are transmitted from one person to another.
→ Virus enters into the body through body fluids, air, mosquitoes and animals.
→ Aids : Acquired Immuno Deficiency Syndrome.
→ HIV : Human Immuno-deficiency Virus.
→ Bacteria multiply through binary fission.
→ Leptospira is the bacteria that causes rat fever.
→ Corynebacterium diphtheria is the pathogen of Diphtheria.
→ Tuberculosis is caused by the bacterium Mycobacterium tuberculosis.
→ The toxins produced by the fungi cause diseases.
→ Malaria is caused by Plasmodium, a protozoa.
→ Filariasis is caused by filarial worms that are spread by Culex mosquitoes.
→ Haemophilia : The condition in which excess blood is lost even through minor wounds.
→ Sickle cell anaemia : The condition in which the structure of haemoglobin changes and this in turn decreases its oxygen carrying capacity.
→ Cancer : A condition caused by uncontrolled division of cells and their spread to other tissues.
→ Life style diseases : Caused by unhealthy living style.
→ Animal diseases are caused by microorganisms like bacteria, virus.
→ Plant diseases are caused by microorganisms like bacteria, virus and fungi.
→ We can keep away diseases by practising healthy habits.