Class 12 NEET Biology Human Health and Diseases Questions Part 1

(a) : Typhoid is caused by Salmonella typhi. The organisms of the disease are present in the stool. They may be present in urine. They can, therefore, be carried by water and contaminated food. Their spread through water can give rise to severe epidemics. Polio is caused by Enterovirus. TB is caused by Mycobacterium tuberculosis. Tetanus is caused by Clostridium tetani.