Explain why a freshwater fish cannot survive in salt water.

The freshwater fish cannot survive in salt water because "water from the body of the fish would flow out to the extremely saline water and the fish cannot survive out of dehydration."

Explanation:

The freshwater in which the fish live is the hypo tonic solution for the fish, but when we talk about the salt water the absorption of the salt is more in it. For the fact osmosis, the water will subsequently flow through the body. Because of the salt water  having  high absorption of salt  that is being considered as the solute particles. If more water will flow out of the fish body it will lead to the dehydration, and ultimately the fish will cannot survive.

the backbone of the dna and rna compound is sugar phosphate.