CBSE Class 9 Answered
The person suffering from an infectious disease can serve as a medium for further spread of infections to other people. If someone is suffering from cold and cough in the class, it is likely that the children sitting around will be exposed to the infection. However, not all of them will catch the infection. This may be due to a strong immune system.
Our immune system is a major factor that determines the number of microbes surviving inside the body. It fights against the microbes that cause diseases. As we get older our immune system learns how to deal with more and more viruses as we generate antibodies each time we get cold and cough. Children usually escape cold and cough infection because of their strong immune system which involves some white blood cells (WBCs) which normally fight off pathogenic microorganisms. These WBCs become active every time disease-causing microbes enter the body.
Sobhan seating next to Ranjan might be having a strong immune system to combat cold and cough infection. Therefore, he did not suffer from the infection. However, Robin’s immune system might be weak and was not able to fight the disease-causing germs of cold and cough. Therefore, he suffered from the infection.