Everything Science

In humans:
-About 5 days after conception, the cells inside the blastocyst, or embryoblast, have started forming the embryo.
-After about 14 days after conception the embroblast is now referred to as an embryo. This is when the nervous system begins to form.
-After about 4 weeks it looks like a tadpole. You can see the head beginning to form and there is a visible tail.
-After 5 weeks, buds begin to appear where the arms and legs are and feature tiny webbed hands and feet. The embryo now has fingerprints.
-After 6 weeks the eyes appear.
-After 2 months the face is similar to that of a primate and the brain is beginning to form.
- At 10 weeks the embryo is now a fetus. The face now looks human and the gender may be detectable via ultrasound.