Question

the genetic code is universal in all living organisms because it ______.

• is a system that worked better than other ancient systems
• was used by an ancient ancestor of all living organisms
• allows humans to transfer dna from one species to another species
• arose independently during the evolution of all organisms

Explanation:

The genetic code's universality stems from common descent—all living organisms inherit the same code from a shared ancient ancestor, which has been conserved through evolution. The other options are incorrect: "worked better" is not the reason for universality, "allows DNA transfer" is a consequence (not cause) of universality, and "arose independently" contradicts the shared origin of the code.

Answer:

B. was used by an ancient ancestor of all living organisms