Compare and contrast the osmoregulatory challenges and solutions used by sharks and freshwater fishes. What will be an ideal response?
Freshwater fishes live in a hypotonic environment; consequently, water continuously enters
the body, and salts diffuse out. To counteract these tendencies, the gills move some water out
and actively transport salts in. In addition, the kidneys excrete large volumes of dilute urine.
Marine cartilaginous fishes such as sharks and rays have evolved the ability to accumulate
and tolerate urea. The accumulation of urea makes their body fluids hypertonic to sea water,which results in an inward flow of water via osmosis. The kidneys excrete excess salt and
large volumes of dilute urine.
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Based on your understanding of metabolism, generalize when an enzyme's rate of activity can be changed
A) before enzyme production B) during enzyme production C) after enzyme production D) at any point-before, during, or after enzyme production
Why do environmentalists ask inhabitants of waterfront properties to reduce their use of plant
fertilizers?
a. The fertilizers may be toxic to microbes. b. The fertilizers may encourage soil erosion. c. The plants may start using more water. d. The runoff from plants may bring about an algal bloom.
The downhill flow of protons through the ATP synthase complex powers the production of ATP
__________________ Indicate whether the statement is true or false.
Which of the following is a function of the kidneys? I) elimination of urea II) reabsorption of valuable solutes III) reabsorbing water
A) I B) II C) III D) all of the above