What are the different means by which infectious diseases are spread?
Infectious diseases can be spread in several ways such as air, water, sexual contact, blood, and vectors.
(i) Through Air: Sneezing or coughing little droplets thrown in the air carry microbes which can cause the spread. For example, tuberculosis, pneumonia, etc. spread through air.
(ii) Sometimes causal micro-organisms get mixed with drinking water and spread water borne diseases. Cholera for example is water borne disease.
(iii) Sexual Contact: Diseases such as syphilis or AIDS are transmitted by sexual contact.
(iv) Certain diseases such as AIDS can spread via blood to blood contact during blood transfusion or pregnancy.
(v) Through vectors : These are intermediaries which carry the infectious agents from the patient to the host. For example mosquitoes spread malaria.
Complete the following table.
Atomic Number |
Mass Number |
Number of Neutrons |
Number of Protons |
Number of Electrons |
Name of the Atomic Species |
9 | - | 10 | - | - | - |
16 | 32 | - | - | - | Sulphur |
- | 24 | - | 12 | - | - |
- | 2 | - | 1 | - | - |
- | 1 | 0 | 1 | 0 | - |
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Welcome to the NCERT Solutions for Class 9 Science - Chapter . This page offers a step-by-step solution to the specific question from Excercise 3 , Question 2: What are the different means by which infectious diseases are spread?....
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