What is a defining characteristic of pathogenic microorganisms?

A defining characteristic of pathogenic microorganisms is their ability to cause diseases. Pathogenic microorganisms, including bacteria, viruses, fungi, and protozoa, have evolved mechanisms to invade host organisms and disrupt normal biological processes, leading to various illnesses. This characteristic distinguishes them from non-pathogenic microorganisms, which may be harmless or even beneficial to human health.

In the context of the other options, wrinkles, acne, and sensitive skin are not characteristics of pathogenic microorganisms. Wrinkles are a sign of aging and skin damage, acne is a skin condition often related to blocked pores and hormonal changes, and sensitive skin refers to a skin type that reacts easily to products or environmental factors. These conditions may be influenced by various factors, but they are not inherently related to the presence or activity of pathogenic microorganisms.