a) The process by which salmon maintain an internal balance is called osmoregulation. Describe how salmon achieve osmoregulation as they migrate between fresh and saltwater environments.  b) Describe what happens to salmon in fresh water. What direction do solutes tend to move via diffusion? What direction does water tend to move via osmosis?

Which molecules are responsible for the high osmolarity of the renal medulla in the mammalian kidney?     "Na+, Cl-, and K+"     "urea, uric acid, and Na+"     "Na+, Cl-, and urea"     "uric acid, urea, and amonia"

The kidneys of different species of amniotes differ widely in their ability to concentrate the urine. What determines the maximum osmolarity of the urine an animal's kidney can produce? Explain why.  (not to long)

Some animals are osmoconformers, meaning that they maintain the tonicity/osmolarity of their body fluids equal to that of the external environment. Hydroids, a type of cnidarian, are osmoconformers. But they don't move and thus are adapted to the environment they live in. A) What would happen if you take a marine hydroid and transfer it into a freshwater aquarium? B) What would happen if you take a freshwater hydroid and transfer it into a saltwater aquarium? C) Sharks are extraordinary osmoconformers. Bull sharks store urea in their tissues and use it to match the tonicity of their tissues to that of the surrounding environment. Some sharks can move from saltwater to freshwater, hypothesize what changes will sharks do in order to adjust when moving from saltwater to freshwater and vice versa. Explain your answer in terms of tonicity and specify the direction of water movement and urea concentration.