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13 Cards in this Set
- Front
- Back
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Define osmolarity and distinguish among isoosmotic, hyperosmotic, and hypoosmotic solutions.
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Osmolarity is solute concentration expressed as molarity.
If two solutions are separated by a selectively permeable membrane have the same osmolarity, they are said to be isoosmotic When two solutions differ in osmolarity, the one with the greater concentration of solutes is said to be hyperosmotic and the more dilute solution is said to be hyposmotic |
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Distinguish between osmoregulators and osmoconformers. Explain why osmoregulation has an energy cost.
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Osmoconformer is isoosmotic with its surroundings and osmoregulator controls its internal osmolarity independent of that of its environment. Osmoregulation has an energy cost because they need to control the water uptake and loss in a hypoosmotic or hyperosmotic environment.
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Distinguish between stenohaline and euryhaline animals, and explain why euryhaline animals include both osmoconformers and osmoregulators.
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Stenohaline cannot tolerate substantial changes in external osmolarity while euryhaline animals can survive large fluctuations in external osmolarity. Certain fish go change depending on their environment like the salmon
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Discuss the osmoregulatory strategies of marine animals
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Some fishes such as cod drink large amounts of sea water and use both their gills and kidneys to rid themselves of salt. Sharks use salt, urea, TMAO, and other compunds maintained in the body fluids of the shark result in an osmolarity very close to that of sea water
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Explain how the osmoregulatory problems of freshwater animals differ from those of marine animals
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The body fluids of freshwater animals must be hyperosmotic because animal cells cannot tolerate salt concentrations as low as those of lake or river water.
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Describe anhydrobiosis as an adaptation that helps tardigrades and nematodes to survive periods of dehydration
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Nematodes and tardigrades go through anhydrobiosis when the environment is at an extreme hydration. This allows them to survive during hard times.
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Describe some adaptions that reduce water loss in terrestrial animals
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Waxy cuticle protects plants, the body covering of most terrestrial animals helps prevent dehydration. some animals are nocturnal. land animals maintain water balance by drinking and eating moist foods and by producting water metabolically through cellular respiration
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Describe the production and elimination of ammonia. Explain why ammonia excretion is most common in aquatic species.
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When nucleic acids and proteins are broken apart for energy or converted to carbohydrates or fats, enzymes remove the nitrogen in the form of ammonia. Many aquatic species have ammonia because it can easly pass through membranes and are readily lost by dissusion to the surrounding water.
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Compare strategies to eliminate waste as ammonia, urea, or uric acid. Note which animal groups are associated with each process and why a particular strategy is most adaptive for a particular group
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Aquatic animals excrete ammonia across the body surface or epithelia into the surrounding
The liver of of mammals and most adult amphibians convert ammonia to less toxic urea, which is carried to the kidneys, concentrated, and excreted with a minimal loss of water. Urea is at a very low toxicity.(mammals adult amphibians sharks some bony fish and turtle) Uric acid is eliminated as a semisolid paste with very little water loss. This is a great advantage for animals with little access to water(snails, insects and reptiles) |
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Describe the key steps in the process of urine production
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Filtration-The excretory tubule collects a filtrate from the blood. Water and solutes are forced by blood pressure across the selectively permeable membranes of a cluster of capillaries and into the excretory tubule
Reabsorption- The transport epithelium reclaims valuable substances from the filtrate and returns them to the body fluids. Secretion- Other substances, such as toxins and acess ions, are extracted from body fluids and added to the contents of the excretory tubule. Excretion- The altered filtrate leaves the system and the body |
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Explain how the loop of henle enhances water conservation by the kidney
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Reabsorption of water continues as the filtrate moves into the descending limb of the water of henle. Here numeroue was channels formed by aquaporin proteins make the transport epithelium freely permeable to water
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Explain how the loop of henle functions as a countercurrent multiplier system
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The countercurrent multiplier system involving the loop of henle maintains a high salt concentraion in the interior of the kidney, enabling the kidney to form concentrated urine.
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Describe the nervous and hormonal control involved in the regulation of the kidney
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Sensory receptors in blood that can tell if your blood gets too salty. Chemoreceptors can detect salinity of blood. ADH increases water reabsorption in the distal tubules and collecting ducts of the kidney
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