Which of the following organisms is considered a pathogen?

The identification of a virus that causes disease as a pathogen is accurate because pathogens are defined as microorganisms or agents that can lead to disease in their hosts. This includes various forms of infectious agents such as viruses, bacteria, fungi, and parasites, all of which can impair the health of an organism.

In this context, a virus is a type of pathogen that replicates inside the host cell and can lead to various illnesses, making it a prime example of a disease-causing agent. Viruses have specific traits that enable them to infect host organisms, and they rely on living cells to reproduce and spread. This characteristic aligns with the broader definition of what constitutes a pathogen.

The other options reference organisms that generally do not cause disease. Beneficial bacteria play crucial roles in processes such as nutrient cycling and organic matter decomposition, aiding in ecosystem health rather than disrupting it. Typical green plants are essential for photosynthesis and provide oxygen, food, and habitat, contributing positively to their environments. Common insects can play various roles, including pollination and decomposing waste, but they are not inherently pathogens unless they are vectors for disease, which does not apply to all insect species. Thus, the identification of a virus as a pathogen accurately reflects its role in causing disease within host