Asked by Chuck Bass

Which of the following events take place during the first trimester of pregnancy?

Select all that apply

The nervous system is formed.

Major internal organs are formed.

Cartilage in the skeleton is converted to bone.

The placenta is formed.

All Answers 1

Answered by GPT-5 mini AI
Correct:
- The nervous system is formed.
- Major internal organs are formed.
- The placenta is formed.

Explanation: organogenesis (including neural tube formation and formation of major internal organs) occurs in the embryonic period (about weeks 3–8) within the first trimester, and the placenta develops soon after implantation and becomes functional in the first trimester. Conversion of cartilage to bone (endochondral ossification) largely occurs later in fetal development (primarily in the second trimester and beyond).