A normal human pregnancy lasts forty weeks, divided into three trimesters. What is a key event during the first trimester of pregnancy? The embryo is forming all its major structures and is most sensitive to alcohol and drugs. Most organ systems are fully developed and functional. The lungs develop, and the head points down toward the cervix. The gender of the fetus can be determined without studying the chromosomes.
Added by David D.
Step 1
Therefore, the key event during the first trimester is: Show more…
Show all steps
Your feedback will help us improve your experience
Anand Jangid and 55 other Biology educators are ready to help you.
Ask a new question
Labs
Want to see this concept in action?
Explore this concept interactively to see how it behaves as you change inputs.
Key Concepts
Recommended Videos
Adi S.
Recommended Textbooks
Biology for AP Courses
Objective Biology for NEET
Introduction to General, Organic and Biochemistry
18,000,000+
Students on Numerade
Trusted by students at 8,000+ universities
Watch the video solution with this free unlock.
EMAIL
PASSWORD