45) When bar-headed geese fly at very high altitudes (possibly over Mount Everest!), they
breathe very thin air where the partial pressure of oxygen is very low compared to that at sea
level. Which of the following adaptions would help the geese efficiently exchange gases when
flying at high altitudes?
A) hemoglobin that has a high affinity for oxygen
B) hemoglobin that has a low affinity for oxygen
C) hemoglobin that has a high affinity for carbon dioxide
D) hemoglobin that has a low affinity for carbon dioxide
46) When bar-headed geese fly at very high altitudes (possibly over Mount Everest!), they
breathe very thin air where the partial pressure of oxygen is very low compared to that at sea
level. They are able to do this because they have a modified version of the hemoglobin protein.
Which of the following is their hemoglobin protein most likely similar to in terms of its ability to
bind oxygen?
A) an adult human
B) a human fetus
C) a bird that lives at sea level
D) an earthworm
47) Some crocodiles and turtles have an exceptional ability to divert blood flow through the heart
when they are diving and no longer breathing and exchanging gases. Which of the following
most likely occurs when these animals dive?
A) Instead of flowing to the lungs, blood travels to the rest of the body to support bodily
functions.
B) Instead of flowing to the body, blood travels to the lungs to exchange gases.
C) Instead of flowing to the capillaries, blood travels alveoli to exchange gases.
D) Blood flow ceases altogether since gases cannot be exchanged while diving.
48) When you hyperventilate (breathe too fast), respiratory alkalosis (elevated blood pH) can
occur, which can cause you to faint. A common but potentially dangerous method to reverse
respiratory alkalosis is to hold a paper bag over your mouth and take normal breaths, thereby
rebreathing the exhaled air. How might this method reverse respiratory alkalosis?
A) Inhaling oxygen exhaled into the bag will cause oxygen to diffuse back into the blood and
react with water to form carbonic acid, and blood pH will decrease.
B) Inhaling oxygen exhaled into the bag will cause oxygen to diffuse back into the blood and
react with water to form carbonic acid, and blood pH will increase.
C) Inhaling carbon dioxide exhaled into the bag will cause carbon dioxide to diffuse back into
the blood and react with water to form carbonic acid, and blood pH will increase.
D) Inhaling carbon dioxide exhaled into the bag will cause carbon dioxide to diffuse back into
the blood and react with water to form carbonic acid, and blood pH will decrease.
49) Pulmonary fibrosis is a lung disease that is characterized by damage and scarring of lung
tissue. This results in the lungs becoming stiff and inelastic. What function is most likely to be
impaired in someone with pulmonary fibrosis?
A) contraction of the diaphragm
B) relaxation of the diaphragm
C) gas exchange at the alveoli
D) expansion of the lungs
50) The flow rate of a gas through a tube is proportional to the diameter of the tube. Through
which structure in the human respiratory system does air flow the fastest?
A) bronchiole
B) trachea
C) bronchus
D) alveoli
51) Cigarette smoking can sometimes lead to development of a “smoker’s cough,” which results
from paralysis of cilia in the airways. Why would the paralysis of cilia lead to smoker’s cough?
A) Paralyzed cilia can no longer clear the airways of mucus so coughing helps remove it.
B) Paralyzed cilia can no longer provide an immune response to protect the airways from
harmful compounds in the smoke, so coughing is used to try to prevent the compounds from
damaging the airways.
C) Paralyzed cilia lead to a nervous response that “tickles” the airways and induces coughing.
D) Paralyzed cilia push mucus downward into the alveoli, which coughing attempts to remove.
52) Which respiratory structure likely has the largest surface area for gas exchange to occur?
A) the body surface of a worm
B) the alveoli of a pig
C) the tracheal system of a house fly
D) the gills of a trout
53) If the hemoglobin molecules in your red blood cells suddenly were unable to bind carbon
dioxide and hydrogen ions, what would happen to your blood pH?
A) It would increase.
B) It would stay the same.
C) It would decrease.
D) There is not enough information to answer this question.
54) Sometime after a human baby is born, the expression of fetal hemoglobin ceases and the
expression of adult hemoglobin begins. Imagine that a baby is born and this switch from fetal to
adult hemoglobin does not occur. In which part of the world would this baby be well-adapted to
living?
A) high-altitude cities
B) open grasslands
C) sea level at the beach
D) a tropical rain forest
22.2 Art Questions
1) Which part of the diagram shows alveoli?
A) part A
B) part B
C) part C
D) part D
2) At which point(s) in the figure is blood oxygen-rich?
A) points A and B
B) points A and D
C) point C only
D) points D and E
3) At which point(s) in the figure below would the blood have the highest concentration of CO2?
A) point A only
B) points B and C
C) point D only
D) points C and E
4) Which of the figures below represents countercurrent exchange? The arrows indicate direction
of flow, and the numbers indicate temperatures in degrees Celsius.
A) figure A
B) figure B
C) figure C
D) figure D
22.3 Scenario Questions
After reading the paragraphs below, answer the questions that follow.
Many amphibians (including many frogs, toads, and salamanders) spend the early part of their
lives in water but live on land as adults. The adults of many species return to water to breed and
lay their eggs. Frogs have small lungs and supplement their oxygen intake by breathing through
the skin. Although large frogs have more total surface area than smaller frogs, the larger frogs
have a lower surface area/volume ratio (less skin surface relative to their total body volume). To
keep their respiratory surfaces moist, frogs are generally found in wet or very moist locations.
In an experiment designed to investigate oxygen consumption in relation to body size, frogs from
five different species were weighed and placed in a respirometer (a machine that measures
oxygen consumption) for 1 hour. The table shows the results of the experiment.
1) From the data in the table, it is reasonable to conclude that
A) smaller frogs consume less oxygen per gram of body weight.
B) each tested species consumes a different amount of oxygen per gram of body weight.
C) oxygen consumption per gram of body weight is the same for all tested species.
D) oxygen consumption per gram of body weight for the largest species is much higher than that
for the smallest species.
2) If you could alter the shape of a frog so that it was long and thin instead of compact, the frog’s
oxygen transfer efficiency would
A) increase, because the frog would be larger.
B) decrease, because there would be more skin area to keep moist.
C) increase, because the frog would have more surface area in relation to body volume.
D) not change at all, because the body volume would remain constant.
3) You have obtained a frog from a species closely related to the frogs used in the preceding
study. If the frog weighs 30 grams, what do you expect its oxygen consumption in 1 hour to be?
A) 0.30 cc
B) 1.00 cc
C) 1.50 cc
D) 2.00 cc
After reading the paragraphs below, answer the questions that follow.
Physicians routinely give their patients pulmonary function tests in order to measure
characteristics of lung function. The most common of these tests, spirometry, measures both the
volume and the speed of air entering and exiting the lungs. In this test, a person first breathes
normally while breathing into a spirometer, a machine that measures air volume and air speed.
Then the person takes the deepest breath possible and exhales as hard as possible for 6 seconds
into the spirometer. The resulting data are plotted on a graph of volume (y axis) versus time (x
axis). Spirometry is useful not only for assessing lung function in healthy patients but also for
characterizing patients with lung conditions such as pulmonary fibrosis, asthma, or emphysema.
A sample graph for a healthy adult male is shown below. Normal breathing occurs between
points A and B, a maximal inhalation occurs at point C, and a maximal exhalation occurs at point
D. Normal breathing resumes between points E and F.
4) For this data set, how much air is exhaled during a normal breath?
A) 500 mL
B) 1,200 mL
C) 2,300 mL
D) 2,800 mL
5) For this data set, what is the vital capacity?
A) 1,200 mL
B) 2,800 mL
C) 4,600 mL
D) 5,800 mL
6) For this data set, what is the residual volume?
A) 500 mL
B) 1,200 mL
C) 2,300 mL
D) 2,800 mL
7) Patients with emphysema have lungs that are less elastic than normal. As a result, they cannot
exhale as much air as a healthy person can, thereby leaving additional residual volume in the
lungs. How would the preceding graph differ if an emphysema patient’s data were plotted instead
of a healthy person’s?
A) The difference in volume between points A and B would be larger.
B) The difference in volume between points C and D would be larger.
C) Point A would be at a smaller volume.
D) Point D would be at a larger volume.
8) How is spirometry a potentially flawed experimental method to measure lung volume?
A) The test does not sample data for when the patient is breathing normally.
B) There is no way to calculate vital capacity using this method.
C) Patients with lung diseases or disorders cannot take spirometry tests.
D) The patient may be noncompliant and not put forth their best effort in the test.