Chapter 40 questions

Salmon eggs hatch in freshwater. The fish then migrate to the ocean (a hypertonic solution) and, after several years of feeding and growing, return to freshwater to breed. How can these organisms make the transition from freshwater to ocean water and back to freshwater?

Different gill cells are involved in osmoregulation in freshwater than in salt water

In animals, nitrogenous wastes are produced mostly from the catabolism of _____.

Proteins and nucleic acids

The fluid with the highest osmolarity is _____.

Seawater in a tidal pool

If nicotine stimulates ADH release, which of the following is predicted? See Section 40.5 (Page 845) .

Small amounts of concentrated urine

Normal urine contains very little glucose. Diabetics have elevated glucose levels in their blood and urine. Which statement best explains the presence of glucose in the urine of diabetics?

The transport of glucose from the pre-urine within the proximal tubule back to the blood cannot occur at a rate fast enough to remove all of the glucose from the urine.

What is the function of the Loop of Henle in mammalian kidneys? See Section 40.5

To create the kidney's osmotic gradient that permits the reabsorption of water and various solutes

The nitrogenous waste that requires the most energy to produce is _____.

Uric acid

Which nitrogenous waste requires hardly any water for its excretion?

Uric acid

If you are hiking through the desert for several days, which of the following should you drink to ensure proper hydration?

a drink with a combination of water and electrolytes

Ammonia _____.

is soluble in water

The body fluids of an osmoconformer would be _____ with its _____ environment

isoosmotic; saltwater

The necropsy (postmortem analysis) of a freshwater fish that died after being placed accidentally in saltwater would likely show that _____.

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

Among vertebrate animals, urea is ________.

made in the liver by combining ammonia molecules or amino group

For filtration to take place through the fenestrated capillaries of the renal corpuscle, _____.

there must be a greater pressure inside the glomerulus than in the renal tubules

Freshwater fish reside in hypotonic environments. They do not drink water, and they excrete large volumes of hypotonic urine in an effort to osmoregulate. How do they obtain an adequate supply of electrolytes?

Chloride cells on the gill filaments take up additional electrolytes from freshwater.

How might eating salty foods alter urine output? See Section 40.5 (Page 845) .

It would cause more concentrated urine.

What is the correct order of flow of urine as it leaves the body? See Section 40.5 (Page 845) .

Kidney to ureter to bladder to urethra

If ethanol inhibits ADH release, which of the following is predicted? See Section 40.5 (Page 845) .

Large amounts of dilute urine

Which of the following most accurately describes selective permeability?

Only certain molecules can cross a cell membrane.

The force driving simple diffusion is ________, while the energy source for active transport is ________.

The concentration gradient and ATP

Why are the renal artery and vein critical to the process of osmoregulation in mammals?

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.

What role do chloride cells play in osmoregulation of marine bony fishes?

They are involved in excretion of excess salt.

Ammonia is likely to be the primary nitrogenous waste in living conditions that include _____.

lots of fresh water flowing across the gills of a fish

Organisms categorized as osmoconformers are most likely _____.

marine

Both marine bony fishes and terrestrial animals lose water to the environment. However, a difference is that the bony fishes lose water by ________, while the terrestrial animals lose it by ________.

osmosis; evaporation

Materials are returned to the blood from the filtrate by which of the following processes?

selective reabsorption

What is the function of the osmotic gradient found in the kidney? The osmotic gradient allows for _____.

the precise control of the retention of water and electrolytes

Salmon and sea bass are useful for studies of the role of the gills in osmoregulation in fishes because ________

they live in freshwater and in seawater at different life history stages

The advantage of excreting nitrogenous wastes as urea rather than as ammonia is that _____.

urea is less toxic than ammonia