Mastering Biology Chapter 44

Antidiuretic hormone (ADH) and the renin-angiotensin-aldosterone system (the RAAS) work together in maintaining osmoregulatory homeostasis through which of the following ways? A) ADH regulates the osmolarity of the blood by altering renal reabsorption of water, and the RAAS maintains the osmolarity of the blood by stimulating Na+ and water reabsorption. B) ADH and the RAAS work antagonistically; ADH stimulates water reabsorption during dehydration and the RAAS causes increased excretion of water when it is in excess in body fluids. C) Both stimulate the adrenal gland to secrete aldosterone, which increases both blood volume and pressure via its receptors in the urinary bladder. D) ADH and the RAAS combine at the receptor sites of proximal tubule cells, where reabsorption of essential nutrients takes place.

A) ADH regulates the osmolarity of the blood by altering renal reabsorption of water, and the RAAS maintains the osmolarity of the blood by stimulating Na+ and water reabsorption.

If you are hiking through the desert for several days, one would pack which of the following to ensure proper hydration? A) a drink with a combination of water and electrolytes B) caffeinated beverages C) bottled water kept at room temperature D) bottled water that had been frozen to ensure that it would be as cold as possible

A) a drink with a combination of water and electrolytes

Which process in the nephron is least selective? A) filtration B) reabsorption C) active transport D) secretion E) salt pumping by the loop of Henle

A) filtration

Urea is produced in the A) liver from NH₃ and CO₂. B) liver from glycogen. C) kidneys from glucose. D) kidneys from glycerol and fatty acids. E) bladder from uric acid and H₂O.

A) liver from NH₃ and CO₂.

The necropsy (postmortem analysis) of a freshwater fish that died after being placed accidentally in saltwater would likely show that A) loss of water by osmosis from cells in vital organs resulted in cell death and organ failure. B) high amounts of salt had diffused into the fish's cells, causing them to swell and lyse. C) the kidneys were not able to keep up with the water removal necessary in this hyperosmotic environment, creating an irrevocable loss of homeostasis. D) the gills became encrusted with salt, resulting in inadequate gas exchange and resulting asphyxiation. E) brain cells lysed as a result of increased osmotic pressure in this hyperosmotic environment, leading to death by loss of autonomic function.

A) loss of water by osmosis from cells in vital organs resulted in cell death and organ failure.

Ammonia is likely to be the primary nitrogenous waste in living conditions that include A) lots of fresh water flowing across the gills of a fish. B) lots of seawater, such as a bird living in a marine environment. C) lots of seawater, such as a marine mammal (e.g., a polar bear). D) a terrestrial environment, such as that supporting crickets. E) a moist system of burrows, such as those of naked mole rats.

A) lots of fresh water flowing across the gills of a fish.

The osmoregulatory/excretory system of a freshwater flatworm is based on the operation of A) protonephridia. B) metanephridia. C) Malpighian tubules. D) nephrons. E) ananephredia.

A) protonephridia.

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 the toxic ammonia. C) The highly toxic urea makes the pool uninhabitable to potential competitors. D) Urea forms an insoluble precipitate. E) Urea makes lungfish tissue hypoosmotic to the pool.

B) Small stagnant pools do not provide enough water to dilute the toxic ammonia.

Why are the renal artery and vein critical to the process of osmoregulation in vertebrates? A) The kidneys require constant and abnormally high oxygen supply to function. B) The renal artery delivers blood with nitrogenous waste to the kidney and the renal vein brings blood with less nitrogenous wastes away from the kidneys. C) The kidneys require higher than normal levels of hormones. D) The renal artery and vein are the main pathways regulating how much is produced by the kidneys.

B) The renal artery delivers blood with nitrogenous waste to the kidney and the renal vein brings blood with less nitrogenous wastes away from the kidneys.

A necropsy (postmortem analysis) of a marine sea star that died after it was mistakenly placed in fresh water would likely show that it died because A) it was stressed and needed more time to acclimate to the new conditions. B) it was so hyperosmotic to the fresh water that it could not osmoregulate. C) the sea star's kidneys could not handle the change in ionic content presented by the fresh water. D) its contractile vacuoles ruptured.

B) it was so hyperosmotic to the fresh water that it could not osmoregulate.

Increased antidiuretic hormone (ADH) secretion is likely after _____. A) drinking lots of pure water B) sweating-induced dehydration increases plasma osmolarity C) eating a small sugary snack D) blood pressure becomes abnormally high

B) sweating-induced dehydration increases plasma osmolarity

The force driving simple diffusion is _____, while the energy source for active transport is _____. A. the concentration gradient; ADP B. the concentration gradient; ATP C. transmembrane pumps, electron transport D. phosphorylated protein carriers; ATP

B. the concentration gradient; ATP

Which of the following animals generally has the lowest volume of urine production? A) a vampire bat B) a salmon in fresh water C) a marine bony fish D) a freshwater bony fish E) a shark inhabiting freshwater Lake Nicaragua

C) a marine bony fish

Excessive formation of uric acid crystals in humans leads to A) a condition called diabetes, where excessive urine formation occurs. B) a condition of insatiable thirst and excessive urine formation. C) gout, a painful inflammatory disease that primarily affects the joints. D) the absence of urea in the urine. E) osteoarthritis, an inevitable consequence of aging.

C) gout, a painful inflammatory disease that primarily affects the joints.

After drinking alcoholic beverages, increased urine excretion is the result of A) increased aldosterone production. B) increased blood pressure. C) inhibited secretion of antidiuretic hormone (ADH). D) increased reabsorption of water in the proximal tubule. E) the osmoregulator cells of the brain increasing their activity.

C) inhibited secretion of antidiuretic hormone (ADH).

Excretory organs known as Malpighian tubules are present in A) earthworms. B) flatworms. C) insects. D) jellyfish. E) sea stars.

C) insects.

A primary reason that the kidneys have one of the highest metabolic rates of all body organs is that A) it stores the body's excess fats. B) it has membranes of varying permeability to water. C) it operates an extensive set of active-transport ion pumps. D) it is the body's only means of shedding excess nutrients. E) it has an abundance of myogenic smooth muscle.

C) it operates an extensive set of active-transport ion pumps.

Processing of filtrate in the proximal and distal tubules A) achieves the sorting of plasma proteins according to size. B) achieves the conversion of toxic ammonia to less toxic urea. C) maintains homeostasis of pH in body fluids. D) regulates the speed of blood flow through the nephrons. E) reabsorbs urea to maintain osmotic balance.

C) maintains homeostasis of pH in body fluids.

In animals, nitrogenous wastes are produced mostly from the catabolism of A) starch and cellulose. B) triglycerides and steroids. C) proteins and nucleic acids. D) phospholipids and glycolipids. E) fatty acids and glycerol.

C) proteins and nucleic acids.

After blood flow is artificially reduced at one kidney, you would expect that kidney to secrete more of the hormone known as A) erythropoietin. B) angiotensinogen. C) renin. D) antidiuretic hormone. E) atrial natriuretic peptide.

C) renin.

The osmoregulatory process called secretion refers to the A) formation of filtrate at an excretory structure. B) reabsorption of nutrients from a filtrate. C) selective elimination of excess ions and toxins from body fluids. D) formation of an osmotic gradient along an excretory structure. E) expulsion of urine from the body.

C) selective elimination of excess ions and toxins from body fluids.

Natural selection should favor the highest proportion of juxtamedullary nephrons in which of the following species? A) a river otter B) a mouse species living in a tropical rain forest C) a mouse species living in a temperate broadleaf forest D) a mouse species living in a desert E) a beaver

D) a mouse species living in a desert

The transfer of fluid from the glomerulus to Bowman's capsule A) results from active transport. B) transfers large molecules as easily as small ones. C) is very selective as to which subprotein-sized molecules are transferred. D) is mainly a consequence of blood pressure in the capillaries of the glomerulus. E) usually includes the transfer of red blood cells into Bowman's capsule.

D) is mainly a consequence of blood pressure in the capillaries of the glomerulus.

Unlike an earthworm's metanephridia, a mammalian nephron A) is intimately associated with a capillary network. B) forms urine by changing fluid composition inside a tubule. C) functions in both osmoregulation and excretion. D) receives filtrate from blood instead of coelomic fluid. E) has a transport epithelium.

D) receives filtrate from blood instead of coelomic fluid.

Terrestrial organisms lose water through evaporation. In what ecosystem might an entomologist find a good study organism to examine the prevention of water loss?

Desert

An excretory system that is partly based on the filtration of fluid under high hydrostatic pressure is the A) flame bulb system of flatworms. B) protonephridia of rotifers. C) metanephridia of earthworms. D) Malpighian tubules of insects. E) kidneys of vertebrates.

E) kidneys of vertebrates.

To maintain homeostasis freshwater fish must _____.

excrete large quantities of water