Certificate In Psychology (CPSY) Practice Exam

What does the seventh month of pregnancy refer to as the "age of viability"?

1. The fetus has doubled in weight.

2. The fetus has almost all nerve cells.

3. The fetus's lungs can breathe air.

4. The fetus's external sex characteristics are visible.

The correct answer is: The fetus's lungs can breathe air.

The term "age of viability" refers to the stage in pregnancy where the fetus has developed to the point that it has a reasonable chance of surviving outside the womb. This typically occurs around the seventh month of pregnancy. A key factor contributing to this viability is the development of the lungs. By this stage, the fetus's lungs have matured sufficiently to allow for adequate gas exchange, meaning the fetus is capable of breathing air, albeit with some medical assistance. While factors such as weight gain, nerve cell development, and the visibility of external sex characteristics are important milestones in fetal development, they do not directly impact the fetus's ability to survive independently outside the womb as significantly as lung maturity does. Therefore, the correct answer highlights the critical role that lung development plays in achieving viability during the seventh month of pregnancy.