The typical American child is exposed to about ______ food commercials each year. (Fill in the blank)

Answer to q. 1

10,000

Answer to q. 2

Cigarette smoke contains many harmful ingredients, many of which are carcinogens. Nicotine and carbon monoxide, both carcinogens, pass through the placenta and reach the fetus. Carbon monoxide is toxic. It decreases the amount of oxygen available to the fetus. Oxygen deprivation, in turn, is connected with impaired motor development, academic delays, learning disabilities, mental retardation, and hyperactivity. The baby is likely to be smaller if the mother smokes, and babies are more likely to be stillborn or die soon after birth if the mother smokes.

Answer to q. 3

Environmental; genetic

Answer to q. 4

Exposure to particular teratogens is most harmful during critical periods that correspond to times when organs are developing. For example, the heart develops rapidly in the third to fifth weeks after conception, and so is most vulnerable to certain teratogens at this time. The arms and legs are most vulnerable in the fourth to eights weeks. The major organ systems are most vulnerable during the embryonic stages. Some teratogens are harmful throughout the entire course of prenatal development.

Answer to q. 5

Most

Answer to q. 6

Maternal malnutrition has been linked to low birth weight, prematurity, retardation of brain development, cognitive deficiencies, behavioral problems, and cardiovascular disease. Maternal obesity is linked with a higher risk of stillbirth and neural tube defects. Inadequate weight gain increases the chances of having a premature or low-birth-weight baby.

Answer to q. 7

16 and 25 percent