week2 nursing and the aging family

Week 2:Question for Discussion
Chapter 3 –  Biological Theories of Aging & Age Related Physical Changes. Chapter 4 –  Psychosocial, Spiritual, and Cognitive Aspects of Aging.
Question(s):Discuss / explain the biological theories of aging.
Guidelines: The answer should be based on the knowledge obtained from reading the book, no just your opinion. All the theories (corresponding chapter in textbook) should be mentioned and explained (mention at least three). Your grade will be an average of all theories.