Answer:
Oxygen and carbon dioxide
Explanation:
Once the respiratory gases have diffused in the lungs, resulting in the blood becoming O2 rich and CO2 being exhaled, the next stage of transporting the O2 rich blood to the tissues that need it takes place.
At the same time the next batch of CO2 rich blood must be brought to the lungs for the process to take place again.
Mitochondria and chloroplasts may have once been prokaryotes <span>because of the Endosymbiosis theory.</span>
Answer:
1. D,
2. C,
3. A,
4. C,
5. B
Explanation:
those are the answers to the questions
This goes back to Darwin's theory of Evolution. This why certain animals are different colors. This is to protect them from natural predators so the population stays high or also why giraffes have long necks so they can reach food up on trees.