Which small organisms can cause diseases in other living things?

Bacteria are indeed small organisms that can cause diseases in other living things. They are unicellular microorganisms that can be found almost everywhere, including within the human body. While many bacteria are harmless and even beneficial, certain types are pathogenic, meaning they can lead to infections and diseases. For example, bacteria like Streptococcus can cause strep throat, while Escherichia coli (certain strains) can lead to food poisoning.

Understanding that bacteria can be both helpful and harmful helps clarify their role in health and disease. It is also important to note that although other choices like viruses and parasites also cause diseases, the question specifically focuses on small organisms. Germs is a more general term that can refer to bacteria, viruses, and other pathogens, which may not help in identifying the specific organism contributing to the disease.