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physiological systems of animals operate in what kind of environment?
fluid environment
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osmoregulation
regulates solute concentrations and balances the gain and loss of water
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freshwater animals show adaptions that reduce uptake of what and conserve what?
reduce water uptake and conserve solutes
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excretion
gets rid of nitrogenous metabolites and other waste products
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cells require a balance between osmotic what and loss of what?
osmotic gain and loss of water
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osmolarity
the solute concentration of a solution, determines the movement of water across a selectively permeable membrane
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if two solutions are isoosmotic what does this mean?
- the movement of water is equal in both directions
- If two solutions differ in osmolarity, the net flow of water is from the hypoosmotic to the hyperosmotic solution
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osmoconformers
consisting only of some marine animals, are isoosmotic with their surroundings and do not regulate their osmolarity
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osmoregulators
expend energy to control water uptake and loss in a hyperosmotic or hypoosmotic environment
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most animals are stenohaline or euryhaline?
stenohaline
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stenohaline
they cannot tolerate substantial changes in external osmolarity
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euryhaline
animals can survive large fluctuations in external osmolarity
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most marine invertebrates are osmo what, while most marine vertebrates are osmo what?
- invertebrates osmoconformers
- vertebrates osmoregulators
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hypoosmotic
containing a lower concentration of osmotically active components than a standard solution.
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marine bony fishes are what to sea water?
- hypoosmotic- sea water is saltier than them
- They lose water by osmosis and gain salt by diffusion and from food
- They balance water loss by drinking seawater and excreting salts
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Freshwater animals constantly take in water by what from their hypoosmotic environment
osmosis
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freshwater osmoregulation
- They lose salts by diffusion and maintain water balance by excreting large amounts of dilute urine
- Salts lost by diffusion are replaced in foods and by uptake across the gills
- –Active movement of chloride ions brings in sodium ions
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adaption called anyhyrobiosis
- Some aquatic invertebrates in temporary ponds lose almost all their body water and survive in a dormant state
- (phylum tardigrade)
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phylum tardigrada
- –Water bears
- Can survive extreme conditions
- –Temperatures from 151°C (for a few minutes) to -200°C for days
- –Pressures from the vacuum of space to 1200 atmospheres
- –Complete Dehydration
- –Intense radiation
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Fairy shrimp live in?
- vernal pools
- Eggs can survive years without water
- Adults live fast and furious
- Many species threatened
- –Development and draining of habitats
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Bdellodia rotifers
- Rapidly dehydrate and survive in cysted state
- –When recovering from dessication they will incorporate foreign DNA into their genome
- –Plant, fungi and Bacterial DNA
- Parthenogenic for millions of years
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transport epithelia
- are specialized epithelial cells that regulate solute movement
- They are essential components of osmotic regulation and metabolic waste disposal
- They are arranged in complex tubular networks
- An example is in salt glands of marine birds, which remove excess sodium chloride from the blood
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land animals manage water budgets by what?
drinking and eating moist foods and using metabolic water
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how do desert animals get major water savings?
from simple anatomical features and behaviors such as a nocturnal life style
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