The chloride cells of fish gills have a high density of mitochondria. How does this characteristic relate to the functional role of chloride cells?
Would you expect other epithelial cells involved in ion transport to contain large numbers of mitochondria? Explain.

What effect does antidiuretic hormone (ADH) have on the nephron?

a. It increases the water permeability of the descending limb of the loop of Henle.

b. It decreases the water permeability of the descending limb of the loop of Henle.

c. It increases the water permeability of the collecting duct.

d. It decreases the water permeability of the collecting duct.

In Gila monsters, the organ in which water from urine is reabsorbed into the bloodstream is the___________.             .

Compare and contrast the types of nitrogenous wastes excreted by animals. Identify which type can be excreted with the least water, which is most toxic, and which waste is excreted by bony fishes, by mammals, and by insects. Which type would you expect to be produced by embryos inside eggs laid on land?

Explain why mammals would not be able to produce concentrated urine if their nephrons lacked loops of Henle.

Scientists have noted that marine invertebrates tend to be osmoconformers, while freshwater invertebrates tend to be osmoregulators. Suggest an explanation for this phenomenon.

Biologists have been able to produce mice that lack functioning genes for aquaporins. How would the urine of these mice compare to that of mice with normal aquaporins?

a. Lower volume and lower osmolarity

b. Lower volume and higher osmolarity

c. Higher volume and lower osmolarity

d. Higher volume and higher osmolarity