Answer to Question 1
Programmed theories:
- Cellular clock theory.
- Hormonal stress theory.
- Immunological theory.
Cellular damage theories:
- Wear-and-tear theory.
- Free-radical theory.
- Cross-linking theory.
Note: Aging is an extremely complex biological process that may not be explained by a single theory or cause.
Answer to Question 2
- Eat a well-balanced diet containing a variety of foods including grains, fruits and vegetables, nonfat or low-fat dairy products or other calcium-rich foods, and meat or beans each day.
- Approximately three 8-ounce glasses of low-fat milk each day, combined with the calcium from the rest of a normal diet, is enough to meet the recommended daily requirements for most individuals. Foods fortified with calcium and calcium supplements can assist those who do not consume an adequate amount of calcium-rich foods.
- For many, especially elderly individuals, getting enough vitamin D from sunshine is not practical. These individuals should look to boost their vitamin D levels through diet. Vitamin D is also available in supplements.
- In addition to meeting recommended guidelines for physical activity (at least 30 minutes a day for adults and 60 minutes for children), specific strength and weight-bearing activities are critical to building and maintaining bone mass throughout life.
- Individuals should see a health care provider if they have a medical condition or use medications that can affect the skeleton. Women should also see their health care provider if menstrual periods stop for three months.
Color-enhanced X-ray of the colon taken during a barium enema.
Color mixtures of refracted light—additive process.
How to use Cramer's rule to solve a second-order determinant (Question 2)
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