Question

Life span experts argue that biological aging begins at birth. Which of the following is/are explanation/s of aging?

• A. Cells can divide to a maximum of about 75 to 80 times and that as people age, cells become less capable of dividing.
• B. People age because when cells metabolize energy, the by-products include unstable oxygen molecules known as free radicals.
• C. Aging is due to the decay of mitochondria.
• D. Cell division increases as people age.

Hint:

Most biological theories of aging focus on cumulative cellular damage and reduced regenerative capacity.

Answer 1

The Correct Option is A, B, C

Step 1: Understanding biological explanations of aging.
Biological theories of aging explain aging as a result of cellular and physiological processes that gradually reduce efficiency and repair mechanisms over time.
Step 2: Analysis of options.
(A) Correct: This refers to the Hayflick limit, which states that cells have a finite capacity to divide, leading to aging as division slows down.
(B) Correct: Free radical theory explains aging as damage caused by unstable oxygen molecules produced during metabolism.
(C) Correct: Mitochondrial decay theory suggests that damage to mitochondria impairs cellular energy production, contributing to aging.
(D) Incorrect: Cell division generally decreases, not increases, with age.
Step 3: Conclusion.
Valid biological explanations of aging include cellular division limits, free radical damage, and mitochondrial decay.
Final Answer: (A), (B), (C)