Final answer:
The embryonic stage of human development lasts until the end of the eighth week after fertilization, which is a true statement. This stage is characterized by major developments such as organ formation and setting the foundational structures for the fetus.
Step-by-step explanation:
Embryonic Stage Development Answer
The statement that the embryonic stage lasts until the end of the eighth week is true. The embryonic stage is a critical phase in human development that begins at implantation, and significant changes happen within this time frame, which lasts until the end of the eighth week after fertilization. During weeks five through eight, various developments occur, such as the formation of three cell layers, development of the nervous system, and initial formation of organs. By week eight, which marks the completion of the embryonic stage, the embryo has developed structures like fingers, toes, head, and eyes. Week nine signifies the beginning of the fetal stage, and this lasts until birth. Thus, the transition from embryo to fetus occurs after the eighth week of development
During this embryonic stage, the heart starts to beat, and the formation of the placenta occurs, which will nourish and deliver oxygen to the developing embryo through the umbilical cord. The advancements during this stage lay the groundwork for all of the remaining stages of life. This is a crucial period for organ development, and most major structures in the embryo start to form.