What term refers to the biological aging process at both the cellular and organismal levels?

The term that refers to the biological aging process at both the cellular and organismal levels is senescence. Senescence encompasses the gradual deterioration of function and biological processes that occurs as an organism ages. At the cellular level, senescence involves the changes that lead to a decline in cellular function, including cellular stress responses that result in a halt in cell division and metabolic changes. This cellular senescence can contribute to the aging of tissues and organs, ultimately affecting the entire organism.

This process is characterized by various factors, including telomere shortening, oxidative stress, and cumulative DNA damage, which play a crucial role in the overall aging process. Therefore, senescence serves as a comprehensive term that reflects the biological aging that occurs in both cells and organisms through these interconnected mechanisms.