The embryonic development of animals suggests an order of relation between humans and other animals; some animals being more closely related to humans than the others. Compare the embryos of the salamander, chicken, and monkey to that of the human (top image).

What statements about the embryos are true? Check all that apply.

1. All four animals begin as fertilized eggs.

2. The salamander and the chicken do not have an umbilical cord.

3. Only the fish has ancestral gill slits.

4. All four have identical limb buds.

5. Only the chicken will develop a shell breaker.