Cholera, typhoid, tetanus, and citrus canker are well-known diseases caused by which group of organisms?
Bacteria, specifically pathogenic heterotrophic bacteria, are notorious for causing extensive damage to human beings, crops, farm animals, and pets. According to the NCERT Class 11 Biology textbook, notorious and widespread diseases such as cholera, typhoid, tetanus in humans, and citrus canker in agricultural plants, are all caused by different specific species of bacteria. They typically cause disease by invading tissues or producing potent toxins.
Ref: NCERT Class 11 Biology > Chapter 2: Biological Classification > 2.1 Kingdom Monera