Are microscopic blood vessels with thin walls that allow the passage of oxygen and nutrients to the body and let the blood pick up waste and carbon dioxide.

Body systems are not completely independent they integrate and work together describe one example of the integration between body systems

Diagram of the evolution of land plants?

What molecules will be best used to compare different species with the exact same sequence of amino acids? why would two species have the same protein even if the molecules in question is different? (hint: transcription to translation to protein).