In the fourth week after conception, a minuscule blood vessel that will become the _____ begins to pulsate.
A) lungs
B) stomach
C) kidneys
D) heart

Question

Quizplus · Accepted Answer

In the fourth week after conception, the heart begins to form and a tiny blood vessel starts to pulsate, which eventually becomes the beating heart. The lungs, stomach, and kidneys also develop during gestation, but the formation of the heart is the first major milestone in the development of the cardiovascular system.

In the Fourth Week After Conception, a Minuscule Blood Vessel