How is the DNA in prokaryote different from the DNA in a eukaryote?

Which group of chordates does  notpossess true backbones?                 a.  birds      b.  frogs and toads      c.  lampreys      d.  crocodilians

The picture represents a structure of the respiratory system. which is the function of this structure? to bring air into the body to exchange oxygen with carbon dioxide to carry air to the lungs to release oxygen from the body

In general, characteristics that an organism survive and reproduce become more common in a population over time. what mechanism of evolution cause this change?