Irina is in her first week of pregnancy.During this time,__________.

Question

Quizplus · Accepted Answer

During the first week of pregnancy, the zygote (fertilized egg) begins to divide and form a blastocyst, which will eventually implant in the uterus lining.

Answer: C 
 During the second week of pregnancy, a primitive brain and spinal cord begin to form in the developing embryo.

Option A is incorrect because heart muscles start developing in the third week, option D is incorrect because the embryo is too small to move during the first week of pregnancy.

Irina Is in Her First Week of Pregnancy