Question

question 14 of 25
which happens during the second trimester?
a. blood begins to form.
b. the vocal cords develop.
c. rhythmic breathing starts.
d. the heart starts working.

Explanation:

During the second trimester (weeks 13 - 28 of pregnancy), many fetal developments occur.

• Blood formation begins in the first trimester (around week 3 - 8), so option A is incorrect.
• The heart starts working (first beats) in the first trimester (around week 5 - 6), so option D is incorrect.
• Rhythmic breathing (practice breathing movements) starts in the third trimester (weeks 29 - 40), so option C is incorrect.
• The vocal cords develop during the second trimester.

Answer:

B. The vocal cords develop.