AP BIOLOGY

Detailed explanation-1: -The major levels of organization in the body, from the simplest to the most complex are: atoms, molecules, organelles, cells, tissues, organs, organ systems, and the human organism.

Detailed explanation-2: -The biological levels of organization of living things arranged from the simplest to most complex are: organelle, cells, tissues, organs, organ systems, organisms, populations, communities, ecosystem, and biosphere.

Detailed explanation-3: -Answer and Explanation: The order of structures from least complex to most complex: cell, tissue, organ, organ system.

Detailed explanation-4: -Answer and Explanation: The correct answer is (a) organ systems, organs, tissues, cells.

Detailed explanation-5: -The most complex level of organization is the organismal level, where all eleven organ systems function in the human organism, the whole living person.