BIOL 212 EXAM 2 COMPREHENSIVE STUDY
GUIDE 2026
◉ The one-way flow of air along parabronchi makes what type of
gas-exchange mechanism possible, at least theoretically?
a.
the same as that occurring in echinoderm skin gills
b.
the same as that occurring in fish gills
c.
the same as that occurring in insect tracheae
d.
the same as that occurring in mammalian lungs.
Answer: b.
the same as that occurring in fish gills
◉ When the air in a testing chamber is specially mixed so that its
oxygen content is 10 percent and its overall air pressure is 400 mm
Hg, then PO2 is ________.
a.
40 mm Hg
b.
,21 mm Hg
c.
82 mm Hg
d.
4 mm Hg
e.
400 mm Hg.
Answer: a.
40 mm Hg
◉ What would be the consequences if we were to reverse the
direction of water flow over the gills of a fish, moving water inward
past the operculum, past the gills, then out of the mouth? This
reversal of water flow would ________.
a.
reduce the efficiency of gas exchange
b.
change the exchange of gases in the body from carbon dioxide out
and oxygen in to carbon dioxide in and oxygen out
c.
increase the efficiency of gas exchange.
Answer: a.
reduce the efficiency of gas exchange
,◉ If other factors are equal, which of the following environments
would have the highest level of dissolved oxygen?
a.
cool freshwater at low elevation
b.
warm freshwater at high elevation
c.
cool freshwater at high elevation
d.
warm, salty water at low elevation
e.
cool, salty water at low elevation.
Answer: a.
cool freshwater at low elevation
◉ In which location would you expect the oxygen concentration to
be the lowest?
a.
the blood
b.
the environment
, c.
the heart
d.
the lungs
e.
within tissues.
Answer: e.
within tissues
◉ Air-breathing insects carry out gas exchange ________.
a.
in the alveoli of their lungs
b.
across the finest branches of the trachea and cell membranes
c.
in their specialized internal gills
d.
in their specialized external gills
e.
across all parts of their thin cuticular exoskeleton.
Answer: b.
across the finest branches of the trachea and cell membranes
GUIDE 2026
◉ The one-way flow of air along parabronchi makes what type of
gas-exchange mechanism possible, at least theoretically?
a.
the same as that occurring in echinoderm skin gills
b.
the same as that occurring in fish gills
c.
the same as that occurring in insect tracheae
d.
the same as that occurring in mammalian lungs.
Answer: b.
the same as that occurring in fish gills
◉ When the air in a testing chamber is specially mixed so that its
oxygen content is 10 percent and its overall air pressure is 400 mm
Hg, then PO2 is ________.
a.
40 mm Hg
b.
,21 mm Hg
c.
82 mm Hg
d.
4 mm Hg
e.
400 mm Hg.
Answer: a.
40 mm Hg
◉ What would be the consequences if we were to reverse the
direction of water flow over the gills of a fish, moving water inward
past the operculum, past the gills, then out of the mouth? This
reversal of water flow would ________.
a.
reduce the efficiency of gas exchange
b.
change the exchange of gases in the body from carbon dioxide out
and oxygen in to carbon dioxide in and oxygen out
c.
increase the efficiency of gas exchange.
Answer: a.
reduce the efficiency of gas exchange
,◉ If other factors are equal, which of the following environments
would have the highest level of dissolved oxygen?
a.
cool freshwater at low elevation
b.
warm freshwater at high elevation
c.
cool freshwater at high elevation
d.
warm, salty water at low elevation
e.
cool, salty water at low elevation.
Answer: a.
cool freshwater at low elevation
◉ In which location would you expect the oxygen concentration to
be the lowest?
a.
the blood
b.
the environment
, c.
the heart
d.
the lungs
e.
within tissues.
Answer: e.
within tissues
◉ Air-breathing insects carry out gas exchange ________.
a.
in the alveoli of their lungs
b.
across the finest branches of the trachea and cell membranes
c.
in their specialized internal gills
d.
in their specialized external gills
e.
across all parts of their thin cuticular exoskeleton.
Answer: b.
across the finest branches of the trachea and cell membranes
