Biology 101 Subject is a course that focuses on the study of living organisms. The term 'ameba' is a five-letter word used to describe a single-celled organism that is capable of changing its shape and moving around. Amebas are found in many different environments, from freshwater to saltwater, and can be beneficial or harmful depending on their environment. They are an important part of the study of biology, and are often studied in Biology 101 Subject courses.