BIOL 1442 CHAPTER 44 PART 1
The osmoregulatory/excretory system of an insect is based on the operation of
Malpighian tubules
Choose a pair that correctly associates the mechanism for osmoregulation or nitrogen removal with the appropriate animal
direct cellular exchange-marine invertebrate
Birds that live in marine environments and thus lack access to fresh drinking water
drink sea water and secrete excess ions mainly through their nasal salt glands
Excretory structures known as protonephridia are present in
flatworms
Many marine and fresh water bony fish achieve osmoregulation via
gain of water through food
Excessive formation of uric acid crystals in humans leads to
gout a painful inflammatory disease primarily affects the joints
Excretory organs known as Malpighian tubules are present in
insects
Which of the following pairs of organisms excrete nitrogenous wastes in the form of uric acid?
insects and birds
Among vertebrate animals, urea
is made in the liver by combining two ammonia molecules with one carbon dioxide
Ammonia
is soluble in water
Compared to the seawater around them, most marine invertebrates are
isoosmotic
The body fluids of an osomoconformer would be _____ with its _____ environment
isoosmotic; saltwater
A necropsy (postmortem analysis) of a marine sea star that dieed after it was mistakenly placed in fresh water would likely show that it died because
it was so hyperosmotic to the fresh water that it could not osmoregulate
Among the following choices, the most concentrated urine is excreted by
kangaroo rats
An excretory system that is partly based on the filtration of fluid under high hydrostatic pressure is the
kidneys of the vertebrates
Urea is produced in the
liver from NH3 and CO2
A 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
Ammonia is likely to be the primary nitrogenous waste in living conditions that include
lots of fresh water flowing across the gills of fish
Organisms catergorized as osmoconformers are most likely
marine
The osmoregulatory/excretory system of an earthworm is based on the operation of
metanephridia
Fresh water flatworms form a urine that is typically
of low solute concentration and of high volume, matching their normal fluid uptake
In animals, nitrogenous wastes are produced mostly from the catabolism of
proteins and nucleic acids
The osmoregulatory/excretory system of a fresh water flatworm is based on the operation of
protonephridia
Birds excrete uric acid as their nitrogenous waste because uric acid
requires little water for nitrogenous waste disposal, thus reducing body mass
The fluid with the highest osomolarity is
sea water in a tidal pool
The osmoregulatory process called secretion refers to the
selective elimination of excess ions and toxins from body fluids
Materials are returned to the blood from the filtrate by which of the following processes?
selective re absorption
Urea is
the primary nitrogenous waste product of humans
Unlike most bony fish, sharks maintain body fluids that are isoosmotic to sea water, so they are considered to by many to be osmoconformers. Nonetheless, these sharks osmoregulate at least partially by
tolerating high levels of urea concentrations that balance internal salt concentrations to sea water osmolarity
the advantage of excreting nitrogenous wastes as urea rather than ammonia is that
urea is less toxic than ammonia
The nitrogenous waste that requires the most energy to produce is
uric acid
The primary nitrogenous waste excreted by birds is
uric acid
Which nitrogenous waste has the greatest number of nitrogen atoms?
uric acid
Which nitrogenous waste requires hardly any water for its excretion?
uric acid
Osmoconforming sharks take in water, as needed,
via osmosis, as their body cells are slightly hyperosmotic to sea water
A human who has no access to fresh water but is forced to drink sea water instead
will excrete more water molecules than taken in, because of the high load of ion ingestion
