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Why Do we Fall Ill — Science STD 9 — Question

Gujarat BoardEnglish MediumSTD 9ScienceWhy Do we Fall Ill5 Marks
Question
What are the different means by which infectious diseases are spread?
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Answer

The different modes of transmission of infectious diseases are:
  • Through Air: Certain disease-causing micro-organisms are expelled in air by coughing, sneezing, talking, etc. These micro-organisms can travel through dust particles or water droplets in air to reach other people. For example, tuberculosis, pneumonia, etc. spread through air.
  • Through Water: Sometimes causal micro-organisms get mixed with drinking water and spread water borne diseases. Cholera for example is water borne disease.
  • Through Sexual Contact: Sexual act between two people can lead to the transfer of diseases such as syphilis, gonorrhoea, AIDS, etc.
  • Through Vectors: Certain diseases spread by animals called vectors. For example mosquitoes spread malaria.

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