Which of the following are true regarding water in the human body?

1. The more fatty tissue there is, the greater is the percentage of body water.
2. Total body water depends on an individual's weight and sex.
3. Water constitutes approximately 45% to 80% of an individual's body weight.
4. Water content is highest in the aged.
a. 1 and 2 only
b. 2 and 4 only
c. 3 and 4 only
d. 2 and 3 only

ANS: D
Water is a major component of the body. It makes up 45% to 80% of an individual's body weight, depending on that person's weight, gender, and age. Leanness is associated with higher body water content. Obese individuals have a lower percentage of body water (as much as 30% less) than do normal-weight individuals. Men have a slightly higher percentage of total body wa-ter than women have. Total percentage of body water in infants and children is substantially greater than it is in adults. In the newborn, water accounts for 80% of the total body weight.