REHS Practice Exam 2025 – Your Complete Prep Guide

The term "trophozoite" refers to the active, feeding stage of protozoan organisms. During this phase, protozoa are metabolically active and engaged in growth and reproduction. Trophozoites are typically characterized by their movement and the ability to ingest food, which allows them to thrive in their environment. This is a critical stage for protozoa, as it is when they are most susceptible to adverse conditions such as changes in temperature, pH, or the presence of chemicals.

In the lifecycle of many protozoa, the trophozoite stage contrasts with the cyst stage, where the organism becomes dormant and resistant to environmental stresses. This distinction is key in understanding how protozoa adapt to different environments and the potential public health implications, as the trophozoite form is often responsible for infections in hosts.