In developing humans, the first trimester is a time of extreme sensitivity to environmental risks, because
A) the placenta is most efficient at this time.
B) the embryo is very small at this time.
C) tissue differentiation is occurring at this time.
D) it is a period of dramatic growth.
E) the organ systems are maturing and particularly sensitive to disruption at this time.

Question

Quizplus · Accepted Answer

During the first trimester, tissue differentiation is occurring, meaning that the embryo is developing its different cell types and organs. This process is crucial and makes the developing fetus very sensitive to any environmental risks that may interfere with proper tissue differentiation.

Answer: E 
 The first trimester is a time of rapid development and maturation of organ systems, and these systems are particularly vulnerable to disruption from environmental risks such as toxins or infections. This is because each organ system has a very specific set of developmental processes that must occur in order for it to mature properly, and any interference with these processes can lead to long-term health problems.

In Developing Humans, the First Trimester Is a Time of Extreme