Biology Marking Period 3 Practice Test 2026 – Your All-in-One Guide to Mastering the Curriculum!

An organ system is a set of organs that collaborate to carry out a major function for the organism. This makes the statement describing a group of organs working together to perform a function the best description. For example, the circulatory system includes the heart, blood vessels, and blood working in concert to move blood, deliver oxygen, and remove wastes. This shows how multiple organs coordinate to achieve a common task. In contrast, a living thing refers to the whole organism, a single organ is just one component, and a group of cells forming tissues describes tissue level organization rather than an integrated system.