Final answer:
By the end of the eighth week, the human embryo begins to look more recognizably human, with distinct arms, legs, and facial features developing, as it grows within the endometrium.
Step-by-step explanation:
During the fifth week of development after fertilization, the embryo is approximately 4 millimeters long and starts to take on a C shape. At this point, it has started to develop its basic structure but looks far less like what we would recognize as a human form. Moving on to the sixth week, the embryo has doubled in size to about 8 millimeters and begins to show more defined features such as limb buds.
By the seventh week, the embryo has grown to about 13 millimeters and continues to develop at a remarkable pace. The limbs are more visible, and the face begins to take shape, making it look more recognizably human. Although the embryo might still have a tail at this stage, it will eventually regress as the fetus develops.
By the end of the eighth week, the embryo has distinct human features with arms and legs, and a rudimentary face takes form. It also undergoes significant growth in size, losing its tail, further distinguishing it from other embryonic stages.