HOSA Biotechnology Practice Test 2025 – 400 Free Practice Questions to Pass the Exam

Humans are classified as multicellular organisms because they are composed of numerous cells that work together to form tissues and organs, which in turn contribute to the overall structure and function of the body. This multicellular organization allows for higher complexity in bodily functions, including specialized cells for different tasks such as muscle contraction, nerve signaling, and immune response.

In contrast, bacteria, protozoans, and many types of algae are typically unicellular, meaning they consist of a single cell that carries out all necessary life processes independently. While some algae can form multicellular structures, many of them exist as single-celled organisms in their unicellular form. Therefore, in a context where you are asked to identify an organism that is not unicellular, humans clearly fit into the multicellular category, distinguishing them from the other listed options.