Chapter 25

Which of the following is not an adaptation for reducing the rate of heat loss to the environment? a. feathers or fur b. increasing blood flow to surface blood vessels c. huddling behavior of penguins d. Countercurrent heat exchange

In each nephron of the kidney, the glomerulus and Bowman's capsule a. filter the blood and capture the filtrate. b. reabsorb water into the blood. c. break down harmful toxins and poisons. d. refine and concentrate the urine for excretion.

As filtrate passes through the loop of Henle, salt is reabsorbed and concentrated in the interstitial fluid of the medulla. This high solute concentration in the medulla enables nephrons to a. excrete the maximum amount of salt. b. neutralize toxins that might be found in the kidney. c. excrete a large amount of water. d. reabsorb water from the filtrate very efficiently.

Birds and insects excrete uric acid, whereas mammals and most amphibians excrete mainly urea. What is the chief advantage of uric acid over urea as a waste product? a. Uric acid is a much simpler molecule. b. It takes less energy to make uric acid. c. Less water is required to excrete uric acid. d. More solutes are removed excreting uric acid.

A freshwater fish would be expected to a. pump salt out through its gills. b. produce copious quantities of dilute urine. c. have scales and a covering of mucus that reduce water loss to the environment. d. do all of the above.

Match each of the following components of blood (on the left) with what happens to it as the blood is processed by the kidney (on the right). Note that each lettered choice may be used more than once. a. passes into filtrate; almost all excreted in urine b. remains in blood c. passes into filtrate; mostly reabsorbed d. secreted and excreted Plasma protein

Match each of the following components of blood (on the left) with what happens to it as the blood is processed by the kidney (on the right). Note that each lettered choice may be used more than once. a. passes into filtrate; almost all excreted in urine b. remains in blood c. passes into filtrate; mostly reabsorbed d. secreted and excreted Toxins or drugs

You are in a room of empty chairs. As the chairs fill with people, you become hotter and hotter. A ceiling fan is turned on, and you feel cooler. You gained heat by ______ and lost heat to the environment by _____. a. conduction... convection b. radiation... convection c. radiation... conduction d. convection... radiation

Which process in the nephron is least selective? a. secretion b. reabsorption C filtration d. passive diffusion of salt

Two endothermic animals are the same size, but one is a carnivore and the other is an herbivore. Predict which of these animals would produce the greatest amount of nitrogenous wastes. Explain.

Some diuretics are on a list of substances that the International Olympic Committee has banned for use by athletes. What do diuretics do? Propose an explanation for how diuretic use could be an unfair advantage for a competitor in a sport like wrestling, in which weight classes are part of the competition.

Dolphins have an insulating layer of blubber that protects them from cold water, but their flippers are not insulated. Propose a hypothesis to explain why dolphin flippers do not freeze. Describe an experiment you could do to test your hypothesis. (You may assume you have equipment for measuring temperatures in dolphin flippers.) What results would you expect if your hypothesis is correct?

In \(1847,\) the German biologist Christian Bergmann noted that mammals and birds living at higher latitudes (farther from the equator) are on average larger and bulkier than related species living at lower latitudes. Suggest an evolutionary hypothesis to explain this observation.

Kidneys were the first organs to be transplanted successfully. A donor can live a normal life with a single kidney, making it possible for individuals to donate a kidney to an ailing relative or even an unrelated individual. In some countries, poor people sell kidneys to transplant recipients through organ brokers. What are the pros and cons associated with organ commerce?

Scientists have found that the quantity of aquaporin molecules inserted in the membranes of collecting duct cells changes in response to ADH levels. Draw a line graph proposing a relationship between ADH levels and its effect on the quantity of aquaporins. Additionally, explain how the relationship between ADH and aquaporins corresponds to situations of dehydration and hydration.