Biological changes refer to alterations in the structure or function of living organisms over time. These changes can occur at various levels, including cellular, tissue, or organ systems. Examples include growth, aging, and adaptations to environmental factors. In humans, biological changes can be seen during different life stages, such as childhood development or the aging process. Factors like genetics, nutrition, and lifestyle choices can influence these changes. Understanding biological changes is essential for fields like medicine, biology, and environmental science.