National League for Nursing (NLN PAX) Exam 2025 – 400 Free Practice Questions to Pass the Exam

Unicellular organisms that possess a nucleus and are capable of movement using cilia are classified as protozoans. Protozoans are a diverse group of eukaryotic microorganisms, which means they have cells with a defined nucleus, distinguishing them from prokaryotic organisms such as monerans, which lack a nucleus.

Many protozoans exhibit various methods of locomotion, with cilia being one of the most common. Cilia are hair-like structures that cover the surface of these organisms and facilitate movement and feeding. This characteristic is a defining feature of certain groups of protozoans, making them unique within the broader classification of living organisms.

In contrast, plants and fungi represent multicellular or unicellular organisms with distinct cellular structures and life processes that do not involve the same type of motility or cellular organization as protozoans. Monerans, which include bacteria and archaea, are primarily prokaryotic and do not have a nucleus, thus further differentiating them from protozoans. The ability to swim via cilia and the presence of a nucleus firmly place these organisms in the protozoan category.