Question

Which of the following developmental events occurs earliest in the prenatal period?

a) the heart starts beating
b) the baby is able to hear
c) the baby is able to see
d) the neural tube develops into a 3-part brain

Answer 1

The heart starts beating earliest in the prenatal period.

Step-by-step explanation:

The correct answer is a) the heart starts beating.

During the early stages of prenatal development, the heart is the first functional organ to develop in the embryo. Around day 21 or 22, the primitive heart starts to beat and pump blood, even as it continues to develop. By day 23, the primitive heart has formed five distinct regions, which will develop into the chambers of the heart and the septa (walls) that separate them by the end of the eighth week after fertilization.