Chapter 44, Problem 6
African lungfish, which are often found in small stagnant pools of fresh water, produce urea as a nitrogenous waste. What is the advantage of this adaptation? a. Urea takes less energy to synthesize than ammonia. b. Small stagnant pools do not provide enough water to dilute ammonia, which is toxic. c. Urea forms an insoluble precipitate. d. Urea makes lungfish tissue hypoosmotic to the pool.
Video transcript
Which of the following animals generally has the lowest volume of urine production? a. vampire bat b. salmon in fresh water c. marine bony fish d. freshwater flatworm
The high osmolarity of the renal medulla is maintained by which of the following? (A) active transport of salt from the upper region of the descending limb. (B) the loose packing of juxtamedullary nephrons. (C) diffusion of urea into the collecting duct. (D) diffusion of salt from the descending limb of the loop of Henle
In which of the following species should natural selection favor the highest proportion of juxtamedullary nephrons? a. a river otter b. a mouse species living in a temperate broadleaf forest c. a mouse species living in a desert d. a beaver