Final answer:
Organisms that live within our bodies and do not typically cause disease are known as normal flora. These include beneficial bacteria, fungi, and protozoa that contribute to our health.
Step-by-step explanation:
Organisms that live inside our bodies without ordinarily causing disease are known as normal flora. These organisms, including bacteria, fungi, and protozoa, are mostly harmless and often beneficial to human health. They protect against pathogens, aid in digestion, and contribute to the production of essential vitamins and nutrients. The Human Microbiome Project is an effort to catalog these microorganisms to better understand their roles in human health. In contrast to normal flora, pathogens are microorganisms that cause diseases, and our immune system has evolved to defend against them.