The period of the embryo ends when
A) the developing organism attaches itself to the uterine wall.
B) bone cells begin to form.
C) the major structures of the body are ready to form.
D) all of the internal organs are functioning.

Question

Quizplus · Accepted Answer

The period of the embryo ends when bone cells begin to form, marking the transition from the embryonic stage to the fetal stage of development. This typically occurs around the end of the eighth week of pregnancy, when the embryo becomes known as a fetus.

The Period of the Embryo Ends When