Final answer:
During the germinal period of prenatal development, the main event is the fertilized egg's journey from the Fallopian tube to the uterus for implantation. This phase precedes the embryonic period, where neurulation and organogenesis occur.
Step-by-step explanation:
Germinal Period of Prenatal Development
The germinal period of prenatal development refers to the earliest phase of pregnancy, beginning with fertilization and ending when the blastocyst implants in the uterus. During this period, the main development that occurs is the travel of the fertilized egg, or zygote, through the Fallopian tube to the uterus where it undergoes several cell divisions. The correct answer to the question is: d. the fertilized egg travels from the Fallopian tube to the uterus. This critical phase lays the groundwork for the subsequent stages of prenatal development—the embryonic and fetal stages.
Subsequent stages, such as the embryonic stage, involve neurulation, where the neural tube develops, and organogenesis, where organs develop within the newly formed germ layers. However, these events occur after the germinal stage. Thus, developments like the formation of the neural tube or the differentiation of arms and legs are not characteristic of the germinal period but rather of the later embryonic period.