Answer:
1. transportation, digestion, and absorption of food.
2. Remove and concentrate waste products from body fluids and return other substances to body fluids
3. Food starts to move through your GI tract when you eat. When you swallow, your tongue pushes the food into your throat.
4. Urine then flows through the nephrons, through a system of converging tubules called collecting ducts.
5. filtering out excess fluid and other substances from the bloodstream and secreting waste.
Hemoglobin levels being lower would be considered a normal change associated with aging.
Explanation:
To calculate the pH of an aqueous solution you need to know the concentration of the hydronium ion in moles per liter (molarity). The pH is then calculated using the expression: pH = - log [H3O+].