QUESTIONS AND CORRECT ANSWERS |
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How do amphibians regulate heat? -------------------------------------They
produce little heat and lose it rapidly by evaporative cooling. Behavioral
adaptations help such as seeing warmer/cooler environments. Mucus helps
with cooling.
How do reptiles regulate heat? -------------------------------------They are
ectotherms and warm themselves by behavioral adaptations. But a few are
endothermic for periods (female pythons that shiver when incubating eggs).
How do fish regulate heat? -------------------------------------Fish are generally
ectothermic but some are endothermic. Endothermic fish help reduce heat
loss by keeping swimming muscles several degrees warmer.
How do invertebrates regulate heat? -------------------------------------Aquatic
ones are thermoconformers with little control over body temp. Terrestrial
ones adjust by behavioral (temp reg in bees in swarms) and physiological
(generate heat) mechanisms.
Osmosis -------------------------------------Diffusion of water through a
selectively permeable membrane
,Hyperosmotic solution -------------------------------------Higher solute (salt)
concentration and lower free H20 concentration. Water flows into the
solution.
Hypoosmotic solution -------------------------------------Lower solute (salt)
concentration, higher free H20 concentration. Water flows out of the
solution.
Isoosmotic solution -------------------------------------No net water movement
How does water flow by osmosis? -------------------------------------Flows from
low concentration of solute to high concentration of solute.
Osmoconformers -------------------------------------isoosmotic with their
surroundings and do not regulate their osmolarity, mostly marine animals
Osmoregulators -------------------------------------expend energy to control
water uptake and loss, many marine vertebrates
Osmoregulation -------------------------------------Controlled movement of
solutes between the internal fluids and the external environment - as well
as the movement of water. Net movement of water requires an osmotic
gradient - requires energy.
Pros: permits animals to live in a variety of habitats
Cons: energy expensive
,Stenohaline -------------------------------------stenos = "Narrow" halos= "salt"
Cannot tolerate substantial changes in external osmolarity
(osmoconformers and osmoregulators)
Euryhaline -------------------------------------Eurys = "Broad" Can survive large
changes in external osmolarity (osmoconformers and osmoregulators)
How do marine teleosts compensate for water loss by osmosis? --------------
-----------------------1. Drinking large amounts of seawater
2. Gills (pumps out chloride and sodium ions) and kidneys (pumps out
various ions and only slight amounts of water) pump out excess salts
3. Excrete urine in relatively small amounts
How do freshwater teleosts regulate water and salt content? -------------------
------------------They constantly take in water by osmosis. To compensate,
they excrete large amounts of dilute urine and replenish let salts by
ingestion of active uptake across gill epithelium.
Compared to the seawater around them, most marine invertebrates are ----
---------------------------------Isoosmotic
How do terrestrial animals maintain osmotic balance on land? -----------------
--------------------1. protective outer layers
2. drinking, and eating moist foods
3. behavioral adaptations (only come out at night when living in the desert)
4. excretory systems that conserve water
, What are the key functions of most excretory systems? --------------------------
-----------1. Filtration
2. Modification
- secretion: adding toxins and other solutes from the body fluids to the
filtrate
-reabsorption: reclaiming valuable solutes
3. Excretion: removing the filtrate form the system
Mammalian kidney -------------------------------------Function in both excretion
and osmoregulation. They conserve water by producing urine that is much
more concentrated than body fluids (solute/salt gradients)
Protonephridia excretory system -------------------------------------Network of
dead-end tubules connected to external openings. Smallest branches
capped by a cellular united called a flame bulb.
Freshwater flatworms, parasitic flatworms, some annelids and mollusc
larvae
Metanephridia excretory system -------------------------------------Functions in
excretion and osmoregulation. Each segment has a pair of open-ended
metanephridia. Tubules collect coelomic fluid and produce dilute urine for
excretion.
Earthworms
Malpighian tubules -------------------------------------Tubules remove
nitrogenous wastes from hemolymph and function in osmoregulation.
Secretes dry waste matter which is an important adaptation to terrestrial
life.