The document outlines different levels of biological organization from simplest to most complex: cells, tissues, organs, organ systems, organisms, populations, communities, ecosystems, biomes, and the biosphere. It provides descriptions of each level, including that cells are the smallest independently functioning unit; tissues are groups of similar cells; organs perform specific functions; organ systems are groups of organs working together; and populations and communities comprise groups of the same or different organisms living together and interacting within an ecosystem. The highest levels of biological organization are biomes, defined as areas with similar plant and animal life, and the biosphere, which encompasses all life on Earth.