Deck 22: Introduction to Oxygen and Carbon Dioxide in Physiology

Question 1

When a diving beetle is underwater with its air bubble, oxygen diffuses from the

A) animal into the bubble.
B) water directly into the animal.
C) bubble into the surrounding water.
D) water into the bubble.

Answer 1

D

Question 2

Respiratory gases move from place to place principally by

A) diffusion.
B) convection.
C) active transport.
D) both diffusion and convective transport.

Answer 2

D

Question 3

The diffusion of an uncharged solute in aqueous solution

A) always diffuses from regions of high concentration to regions of low concentration.
B) will diffuse at a rate exponential to the difference in concentration between regions.
C) involves a passive diffusion component as well as an active diffusion component.
D) diffuses faster compared to charged solutes.

Answer 3

A

Question 4

Which statement regarding the diffusion of materials between gas mixtures and aqueous solutions is false?

A) Diffusion can be predicted by means of partial pressure measurements.
B) Diffusion can be predicted by using concentrations.
C) Respiratory gases can exist in the gas phase as well as dissolved in an aqueous solution.
D) Each gas has a unique solubility in aqueous solution.

Question 5

Which molecules are respiratory gases or chemical forms of respiratory gases?
I) O₂
II) O₃
III) CO₂
IV) HCO₃^-
V) N₂

A) I, II, and III
B) I, II, III, and IV
C) I, III, and IV
D) I, III, and V

Question 6

From the list below, choose the correct order of "physiological urgency" for each element in a given terrestrial animal, beginning with the most urgent.
I) The need for water
II) The need to void CO₂
III) The need to obtain oxygen
IV) The need for food

A) I, III, II, IV
B) III, II, I, IV
C) II, III, I, IV
D) II, III, IV, I

Question 7

The strength of a chemical substance's tendency to undergo a physical or chemical change is called

A) diffusion.
B) its partial pressure.
C) its chemical potential.
D) its potential energy.

Question 8

Which statement regarding gas mixtures in aqueous solutions is false?

A) When a gas dissolves in a solution, it becomes incorporated into the liquid phase.
B) When a gas dissolves in a solution, the molecules become distributed among the H₂O molecules in much the same way as glucose molecules do.
C) Gas in solution can appear as microscopic bubbles.
D) When a large bubble rises to the surface of a solution, the solution is considered to be in the gas phase.

Question 9

The partial pressure of any given gas

A) cannot be calculated from the universal gas law.
B) is dependent on any other gas present.
C) is the individual pressure exerted by the gas in a gas mixture.
D) is proportional to the size of the gas molecule.

Question 10

Which factor is a constant according to the universal gas law?

A) Moles of gas
B) Temperature
C) The universal gas constant
D) Partial pressure

Question 11

According to the universal gas law, _______ is(are) inversely proportional to the partial pressure.

A) moles of gas
B) temperature
C) volume
D) the universal gas constant

Question 12

Refer to the figure shown.
According to the data in the figure, the partial pressures at sea level total

A) 1 atm.
B) 0.5 atm.
C) 100%.
D) 1 kPa.

Question 13

Refer to the figure shown.
If the total pressure was 2 atm, the partial pressure of CO₂ would be _______ atm.

A) 0.04
B) 0.08
C) 0.0004
D) 0.0008

Question 14

Refer to the figure shown.
If the total pressure was 0.5 atm, the partial pressure of O₂ would be _______ atm.

A) 20.95
B) 10.48
C) 0.2095
D) 0.1048

Question 15

Refer to the figure shown.
If the total pressure was 0.1 atm, the percent of O₂ in the gas mixture would be _______%.

A) 20.95
B) 2.095
C) 0.2095
D) 0.02095

Question 16

The fraction of the total moles of gas in a gas mixture is called the

A) mole fractional concentration.
B) volume fractional concentration.
C) partial pressure.
D) absorption coefficient.

Question 17

Suppose that at a temperature of 25°C and pressure of 1 atm, all the O₂ is removed from 10 L of dry atmospheric air, and the remaining gas is restored to the original temperature and pressure. The final volume will be

A) 10 L.
B) about 7.9 L.
C) about 5 L.
D) about 2.1 L.

Question 18

Consider two gas mixtures that are identical in temperature. The concentration of O₂ in mixture #1 is 20 mmol/L, and the concentration of O₂ in mixture #2 is 60 mmol/L. Which statement about the mixtures is true?

A) The partial pressure of O₂ in mixture #2 is three times higher than it is in mixture #1.
B) The partial pressure of O₂ in mixture #2 is 3 times lower than it is in mixture #1.
C) The percent of O₂ in mixture #2 is three times higher than it is in mixture #1.
D) The partial pressures of O₂ in both mixtures are the same.

Question 19

Henry's law relates _______ in aqueous solutions.

A) partial pressure and concentration
B) partial pressure and volume
C) pressure and volume
D) temperature and concentration

Question 20

The _______ of a particular gas in a mixture is the dissolved concentration of that gas when the partial pressure is 1 atm.

A) gas tension
B) absorption coefficient
C) volume fractional concentration
D) density

Question 21

Which statement about gases dissolved in aqueous solutions is true?

A) Different gases have different solubilities.
B) Gas solubilities increase strongly with increasing temperature.
C) Gas solubilities increase with increasing salinity.
D) Gas solubility decreases with increasing molecular size.

Question 22

Which scenarios will result in dissolved gas coming out of solution?
I) Collecting cold creek water, sealing the container, and allowing the solution to warm
II) Collecting warm water, sealing the container, and allowing the solution to cool
III) Collecting cold creek water, adding salt, sealing the container, and allowing the solution to warm
IV) Collecting cold creek water, adding salt, sealing the container, and keeping the solution at the original temperature

A) I, II, and III
B) I, III, and IV
C) II, III, and IV
D) III and IV

Question 23

If a water beetle has used up half of the oxygen in its air bubble, the concentration of oxygen in the bubble is _______ the concentration of oxygen in the water. The partial pressure of oxygen in the bubble is _______ the partial pressure of oxygen in the water. Therefore, oxygen will move from the _______.

A) greater than; less than; water into the bubble
B) less than; less than; bubble into the water
C) less than; less than; water into the bubble
D) greater than; less than; bubble into the water

Question 24

If a water beetle has been using an air bubble as a gill for 1 hour, the O₂ partial pressure will be _______ that of air and the N₂ partial pressure will be _______ that of air.

A) less than; less than
B) equal to; equal to
C) less than; equal to
D) greater than; greater than

Question 25

In which situation would a water beetle's gas bubble last the shortest amount of time as a functional gill?

A) Gas bubble = 0.1 atm O₂, 0.75 atm N₂; water = 0.21 atm of O₂
B) Gas bubble = 0.1 atm O₂, 0.75 atm N₂; water = 0.1 atm of O₂
C) Gas bubble = 0.2 atm O₂, 0.75 atm N₂; water = 0.1 atm of O₂
D) Gas bubble = 1 atm O₂; water = 0.21 atm of O₂

Question 26

Which statement regarding the diffusion of gases is false?

A) Within gas mixtures, gases diffuse in net fashion from areas of relatively high partial pressure to areas of relatively low partial pressure.
B) Within aqueous solutions, gases diffuse in net fashion from areas of relatively high partial pressure to areas of relatively low partial pressure.
C) Across gas‒water interfaces, gases diffuse in net fashion from areas of relatively high partial pressure to areas of relatively low partial pressure.
D) Depending on the circumstance, gases can diffuse from low to high partial pressure.

Question 27

In the diffusion equation, if the units of K are cm² ∙ s^-1, which of the following best represents the units for J?

A) moles ∙ cm^-2 ∙ s^-1
B) moles ∙ sec^-1
C) M ∙ g^-1 ∙ cm^-2
D) M ∙ cm² ∙ s

Question 28

In the diffusion equation, when X increases,

A) J increases.
B) J decreases.
C) J is not affected.
D) J can increase or decrease.

Question 29

In the diffusion equation,

A) permeability is integrated into P₁-P₂.
B) permeability is integrated into K.
C) P₁-P₂ represents permeability.
D) X represents permeability.

Question 30

The Krogh diffusion coefficient (K) for O₂ in air is _______ K for O₂ in water.

A) slightly greater than
B) slightly lower than
C) about 200,000 times lower than
D) about 200,000 times greater than

Question 31

Refer to the figure shown.
The eggs of which animal would most likely have the data profile in the figure?

A) Bald eagle
B) Snapping turtle
C) Bullfrog
D) Largemouth bass

Question 32

Refer to the figure shown.
According to the figure, what was the most likely cause of the zeroing of oxygen partial pressure in the nest?

A) The eggs grew rapidly and used up the available oxygen.
B) The nest was flooded with water.
C) An algal bloom rapidly used up the available oxygen.
D) The eggs hatched and rapidly used up the available oxygen.

Question 33

Which of the following contributes to a respiratory gas partial pressure in solution?
I) O₂
II) CO₂
III) O₂ bound to hemoglobin
IV) HCO₃^- dissolved in plasma

A) I and II
B) I, II, and III
C) I, II, and IV
D) I, II, III, and IV

Question 34

If the diameter of the body of a larval fish exceeded _______, diffusion alone would not be able to meet the demands of its oxygen consumption.

A) 0.1 mm
B) 1.0 mm
C) 5 mm
D) 1 cm

Question 35

A scuba diver remaining at a depth of 50 m for a significant amount of time needs to worry about the possible effects of which gas when he or she ascends?

A) Oxygen
B) Carbon dioxide
C) Nitrogen
D) Nitric oxide

Question 36

The "bends" refers to a physiological condition sustained by a scuba diver in which

A) oxygen gas is too concentrated in the blood due to a dive that lasts too long at a deep depth.
B) nitrogen gas is too concentrated in the blood due to a dive that lasts too long at a deep depth.
C) oxygen gas comes out of solution in the blood due to a rapid ascent.
D) nitrogen gas comes out of solution in the blood due to a rapid ascent.

Question 37

The process that occurs when a gas mixture or an aqueous solution flows and gas molecules in the gas or liquid phase are carried from place to place by the fluid flow is called

A) diffusion.
B) convection.
C) tidal flow.
D) partial pressure.

Question 38

The principal process(es) by which animals use convection to transport gases is(are)

A) ventilation.
B) the pumping of blood.
C) digestion.
D) ventilation and the pumping of blood.

Question 39

The rate of convective gas transport depends on the

A) partial pressure of a particular gas in solution.
B) rate of fluid flow.
C) total concentration of gas in the fluid.
D) rate of fluid flow and the total concentration of gas in the fluid.

Question 40

The movement of water across a fish gill is a good example of

A) permeability.
B) tidal flow.
C) unidirectional flow.
D) Henry's law.

Question 41

Refer to the figure shown.
What process(es) is(are) occurring in the figure?

A) Diffusion
B) Convection
C) Active transport
D) Both diffusion and convection

Question 42

Refer to the figure shown.
Which of the following correctly matches the process with the numerical label?

A) 1 = diffusion; 2 = diffusion; 3 = convection; 4 = diffusion
B) 1 = convection; 2 = diffusion; 3 = diffusion; 4 = diffusion
C) 1 = diffusion; 2 = convection; 3 = diffusion; 4 = convection
D) 1 = convection; 2 = diffusion; 3 = convection; 4 = diffusion

Question 43

Refer to the figure shown.
At what point(s) in the figure is the partial pressure of oxygen the lowest?

A) 1
B) 2
C) 3
D) 4

Question 44

Refer to the figure shown.
Which of the following have the most similar O₂ partial pressures?

A) Ambient air and alveolar gas
B) Alveolar gas and arterial blood
C) Arterial blood and average systemic capillary blood
D) Average systemic capillary blood and mitochondria

Question 45

If active oxygen transport existed, one of its advantages would be

A) that it is a completely passive and therefore energy free process.
B) it could move oxygen down partial pressure gradients.
C) it could move oxygen against partial pressure gradients.
D) it would negate the need for convection.

Question 46

In the analogy of the cascading waterfall, the height of each waterfall is analogous to

A) the heart rate.
B) the rate of blood flow.
C) the partial pressure difference between the corresponding two cell surfaces.
D) the energy difference between the air and the mitochondria.

Question 47

Oxygen enters the mitochondria

A) by diffusion, at a rate that is dependent on the flow of the oxygenated capillary blood.
B) by diffusion, at a rate that is dependent on the difference in O₂ partial pressure between the blood systemic capillaries and the mitochondria.
C) by convection, at a rate that is dependent on the difference in O₂ partial pressure between the blood systemic capillaries and the mitochondria.
D) by convection, at a rate that is dependent on the flow of the oxygenated capillary blood.

Question 48

Which of the following is not a unit of pressure?

A) Millimeters of mercury
B) Pascals
C) Pounds per square inch
D) mL O₂/L

Question 49

STP refers to a(n)

A) temperature of 37°C.
B) pressure of 1 atm.
C) volume of 22.4 L.
D) oxygen percent of 20.95.

Question 50

Why are volumes of gases expressed at standard conditions of temperature and pressure (STP)?

A) Because animals live at different temperatures and pressures.
B) Because the internal conditions of animals are always at different temperatures and pressures.
C) Because the volume occupied by any given molar amount of gas depends on temperature and pressure.
D) Because gases are always expressed as volume.

Question 51

If 2 L of air at 0°C contains 420 mL of O₂, how many mL of O₂ does it contain if the air is warmed to 24°C?

A) 210 mL
B) 384 mL
C) 420 mL
D) about 600 mL

Question 52

If air at 0°C contains 210 mL O₂ per L, how much O₂ does it contain if it is heated to 24°C?

A) 210 mL O₂ per L
B) 420 mL O₂ per L
C) 192 mL O₂ per L
D) 105 mL O₂ per L

Question 53

Which environment has the lowest amount of O₂ per L?

A) Air at 120°C
B) Air at -40°C
C) Freshwater at 24°C
D) Seawater at 40°C

Question 54

Which environment would have the lowest available oxygen?

A) At night, a small summer pond filled with algae
B) The summit of Mount Everest
C) The burrow of a black-tailed prairie dog
D) The burrow of a lemming beneath the arctic snow

Question 55

One of the most important aspects of whether a particular microenvironment will experience hypoxia is

A) the initial oxygen content.
B) the initial carbon dioxide content.
C) rate of air or water exchange.
D) whether the respiratory medium is gas or liquid.

Question 56

Explain the two mechanisms by which oxygen and carbon dioxide move within organisms.

Question 57

Compare and contrast mole fractional concentration versus volume fractional concentration.

Question 58

What are the three most important characteristics of gases dissolved in aqueous solutions? Give examples in your answer.

Question 59

How does diffusion work in allowing a water beetle to use an air bubble as a gill? Why does the bubble not collapse?

Question 60

Why is it important for scuba divers to understand the concept of diffusion, especially as it pertains to N₂?

Question 61

Gas transport in animals often occurs by alternation of convection and diffusion. Explain.

Question 62

What is meant by the oxygen cascade?

Question 63

What is STP and why is it important when expressing volumes of gases? Include information about the relationship between STP and 1 mole of gas.

Question 64

Compare and contrast air and water as respiratory media. Include some approximate quantitative data in your comparison.

Question 65

Compare and contrast the respiratory stresses of terrestrial versus aquatic environments.