What are pathogens?

Pathogens are defined as microorganisms, such as bacteria and viruses, that are capable of causing disease in their hosts. This includes a wide variety of infectious agents that can invade the body, evade the immune system, and lead to illnesses ranging from mild to severe. The understanding of pathogens is crucial in biomedical science as it helps in diagnosing diseases, developing treatments, and implementing preventive measures.

While other choices reference biological concepts, they do not accurately define pathogens. For example, microorganisms that aid in digestion are typically beneficial bacteria or probiotics, which help in breaking down food and are not associated with causing disease. Cells that detoxify harmful substances, such as liver cells, serve a different function in the body and are not classified as pathogens. Lastly, nutrients essential for health refer to vitamins, minerals, and other dietary components needed for overall well-being, which do not fit the definition of pathogens at all. Thus, the correct answer highlights the harmful nature of pathogens that lead to disease.