Human Growth and Development Exam 1 Related

Review Human Growth and Development Exam 1 related questions and content

During Irina's first week of pregnancy, __________.

  • A. heart muscles begin to develop
  • B. the zygote multiplies and forms a blastocyst
  • C. a primitive brain and spinal cord appear
  • D. the embryo can move
Correct Answer: B

Rationale: During the first week of pregnancy, the zygote (fertilized egg) undergoes rapid cell divisions and forms a blastocyst. This is a crucial stage where the cells differentiate and specialize, setting the foundation for the development of the embryo. It is during this time that the zygote implants itself into the uterine wall, initiating the process of pregnancy. Choices A, C, and D are incorrect because during the first week of pregnancy, the focus is on the initial development and multiplication of the zygote, not on the development of heart muscles, a primitive brain and spinal cord, or the embryo's ability to move.