Rickettsia typhi is a species of infectious bacterium that is an obligatory intracellular parasite. This means that, similar to viruses, R. typhi cannot reproduce and survive outside of a eukaryotic cell. Why do we consider viruses nonliving, but rickettsia alive

Due to its characteristics.

Explanation:

We consider viruses are nonliving, but rickettsia are living because rickettsia have the characteristics of bacteria which is a living  and has unique structure. It also survives outside the living cell but not for long time. The rickettsia  remain in their shape and does not form crystalline structure like viruses outside the cell. If there is suitable environment for rickettsia, it can survive in that environment.

it has to be understood that the sea water contains a huge amount of sodium and chlorine ions and if they enter the cell of the atlantic cod fish, the cell will shrivel and the fish will die. to avoid such a condition, the fish uses active transport for the purpose of removing the ions against the gradient.

explanation:

the atlantic cod is not a maritime osmoconformer. its native application of salts is less than that of the seawater it lives in. it is continually falling water from the gills to the ocean via osmosis.

countering that, the fish is going to be swallowing seawater. but since its internal collection of salts is lower than seawater, the fish will want to go free of excess salt, and since that's going upon a gradient, then active transport, requiring energy, must be used to pump out the salt. much marine fish use the organs to filter out the salt and these fish discharge very straight urine.