What are the connections between the byzantine empire and the roman empire?

I believe the answer is
Constantine became emperor of the Eastern Roman Empire in 306. He built a new capital city, called Constantinople.The Byzantine empire was the eastern part of the roman empire that did not fall with the rest of the western part of the empire.

Sea urchins have a unique relationship of oxygen and carbon-di-oxide.

Explanation:

Sea Urchins spread oxygen in a unique way. They take in oxygen by staying inside water. Oxygen enters the body through their gills and tubed feet. CO2, which is waste is released through the anus. They get oxygen only through diffusion, i.e. diffusion of oxygen into the organism. Oxygen diffuses in body through the canals and carbon dioxide diffuses back into the canals. Urchins also have the capability to cope up with rising CO2 levels in the sea.