The biological term for age-related changes in a living organism is senescence. This process involves various physiological changes that occur as an organism ages, leading to a decline in function and increased vulnerability to diseases. Senescence can manifest in different ways, including loss of cellular function, decreased regenerative capacity, and increased mortality risk. Understanding these changes is crucial in fields like gerontology and aging research, as they help scientists unravel the mechanisms behind aging and develop strategies to enhance healthspan.