The greatest vulnerability to teratogens occurs in the ____ stage.
A) zygotic
B) embryonic
C) fetal
D) germinal

Question

Quizplus · Accepted Answer

The embryonic stage is the period of prenatal development from the 2nd to the 8th week after conception. During this time, the major organs and systems of the body are formed and are therefore the most vulnerable to teratogens. The zygotic stage (A) occurs immediately after conception and lasts for about two weeks before the embryo begins to form. The germinal stage (D) is even earlier, lasting from conception until the zygotic stage and primarily involves cell division and the formation of the placenta. The fetal stage (C) begins after the embryonic stage and lasts until birth, during which time the major structures and systems are already in place and the focus is primarily on growth and refinement. While exposure to teratogens during this stage can still have adverse effects, the risks are generally less severe than during the embryonic stage.

The Greatest Vulnerability to Teratogens Occurs in the ____ Stage