Final answer:
The correct order from least to most complex is: molecule, organelle (nucleus), cell, tissue, organ, organ system, organism, population, community, ecosystem, biome, biosphere.
Step-by-step explanation:
The correct order from least to most complex is: molecule, organelle (nucleus), cell, tissue, organ, organ system, organism, population, community, ecosystem, biome, biosphere.
This hierarchy of biological organization starts from the smallest unit, which is a molecule, and moves up to larger and more complex levels, such as cells, tissues, organs, organ systems, and organisms.
As we move beyond individual organisms, we encounter populations, which are groups of the same species in a given area. Populations form communities, which consist of multiple interacting populations.
Ecosystems encompass both living and non-living components, such as plants, animals, and the physical environment. Biomes represent larger-scale regions with similar climate, vegetation, and animal life.
Lastly, the biosphere includes all ecosystems on Earth, where life exists.