https://www.khanacademy.org/science/grade-7-science-tx/xe25057200abc6bd6:organism-structures-and-functions 2026-07-03T03:00:41.306580382Z Organism structures and functions Identify the major human body systems, their structures, and their functions. Learn how cells, tissues, organs, and organ systems are hierarchically organized in both animals and plants. Then, explore how organisms are classified based on characteristics and why this taxonomic system is important. unit