Question 1

Which of the following best explains why oxygen diffuses more rapidly in air than in water?

Accepted Answer

Oxygen concentration is higher and diffusion is faster in air due to lower density and viscosity.

Question 2

A fish in warm water is likely to experience difficulty obtaining oxygen because:

Accepted Answer

Warm water holds less oxygen and fish metabolism increases, raising oxygen demand.

Question 3

Which adaptation most directly increases the rate of gas exchange in animal respiratory organs?

Accepted Answer

Increasing the surface area and reducing the diffusion path length.

Question 4

In mammals, tidal ventilation refers to:

Accepted Answer

Air moving in and out of the lungs via the same pathway, driven by pressure changes.

Question 5

Which equation best describes the rate of diffusion of a gas across a respiratory surface?

Accepted Answer

$$D = k \frac{A(P_1$ - P_2$)}{d}$$

Question 6

Why is carbon dioxide ($$CO_2) $$easier for animals to eliminate than oxygen is to obtain?

Accepted Answer

$$CO_2$$ diffuses more readily due to higher solubility and partial pressure gradients.

Question 7

Which of the following organisms relies primarily on diffusion across its body surface for gas exchange?

Accepted Answer

Lungless salamander

Question 8

Hemoglobin increases the oxygen-carrying capacity of blood by:

Accepted Answer

Binding oxygen reversibly, allowing more oxygen to be transported than plasma alone.

Question 9

Which of the following best describes the role of partial pressure in respiratory gas exchange?

Accepted Answer

Gases diffuse from regions of higher partial pressure to lower partial pressure.

Question 10

Which respiratory structure is unique to insects and allows direct delivery of oxygen to tissues?

Accepted Answer

Tracheal system

Question 11

A person suffers a pneumothorax. What is the immediate effect on their lung function?

Accepted Answer

Collapse of the lung due to loss of pressure differential in the thoracic cavity.

Question 12

Which of the following is a major health risk associated with carbon monoxide ($$CO) $$exposure?

Accepted Answer

$$CO$$ binds to hemoglobin with higher affinity than oxygen, reducing oxygen transport.

Question 13

In aquatic animals, which factor creates a 'double bind' for oxygen uptake as temperature increases?

Accepted Answer

Oxygen solubility in water decreases while metabolic rate increases.

Question 14

Which process is responsible for most carbon dioxide ($$CO_2) $$transport in the blood?

Accepted Answer

Conversion to bicarbonate ions ($$HCO_3$$^-$$) by carbonic anhydrase.

Question 15

Which of the following would most likely increase the efficiency of gas exchange in gills?

Accepted Answer

Maintaining a high partial pressure gradient by one-way water flow.

Question 16

Which of the following is NOT a component of gas exchange systems in larger, complex animals?

Accepted Answer

Digestion

Question 17

If the partial pressure of oxygen in the alveoli ($$P_{O_2$}) is 100 $$mmHg and in the blood is 40 mmHg, what is the direction of oxygen diffusion?

Accepted Answer

From alveoli to blood

Question 18

Which of the following best describes the function of carbonic anhydrase in red blood cells?

Accepted Answer

It speeds up the conversion of $$CO_2 to $$bicarbonate ions.

Question 19

Which of the following would most likely decrease the rate of respiratory gas diffusion across a membrane?

Accepted Answer

Decreasing the surface area available for diffusion.

Gas Exchange and Respiratory Systems in Animals

Study Guide - Practice Questions