External respiration (correct answer) involves the exchange of oxygen and carbon dioxide within the environment.
The exchange of wastes through the skin is just called excretion by sweating.
There is no exchange of nutrients that occur in the lungs but rather absorption of nutrients is the function of the gastrointestinal tract.
The exchange of oxygen and carbon dioxide within the cell is called cellular respiration and involves carrying oxygen from the blood to the cell then the cell uses it as the final electron acceptor in the electron transport chain. The metabolic wastes of the cell, primarily carbon dioxide, goes now to the bloodstream to be exchanged for oxygen in the lungs.
Answer;
Doctors recommend that women avoid most medications and alcohol during pregnancy because these substances may cross the placenta and harm the embryo or fetus.
Explanation;
The doctors recommend that women avoid most medications and alcohol during pregnancy.
Alcohol during pregnancy can cause fetal alcohol syndrome which is a serious condition that can affect a child throughout life.
Some drugs, substances or medications may be harmful during pregnancy, depending on the amount and frequency of use.
