Question 1

The primary advantage of gills versus the body surface for gas exchange in aquatic animals is that ________.

Accepted Answer

Gills provide a much greater surface area for gas exchange compared to the body surface, allowing for more efficient oxygen uptake from water.

Question 2

The respiratory systems of fish and birds are similar in that both______________.

Accepted Answer

Both fish and birds have a unidirectional flow of the environmental medium over their gas exchange surfaces, which allows for efficient oxygen uptake.

Question 3

In the countercurrent exchange in a fish's gills, the oxygen concentration is always _______ in the water than the blood along the entire pathway of each lamella.

Accepted Answer

In the countercurrent exchange system of a fish's gills, water flows over the gill lamellae in the opposite direction to blood flow. This arrangement maintains a gradient where the oxygen concentration in the water is always higher than in the blood, allowing efficient oxygen diffusion into the blood along the entire length of the lamella.

Question 4

The gas exchange surfaces in a mammalian lung are organized into structures that look like clusters of hollow grapes.The hollow, grape-like structures are the________________.

Accepted Answer

The alveoli are the small, grape-like structures in the lungs where gas exchange occurs. They provide a large surface area for oxygen and carbon dioxide to be exchanged between the air and the blood.

Question 5

In the future, it may be possible to screen for a number of different types of cancer by a simple blood test.If a blood test indicates a very early stage of lung cancer, where is the most likely place that the tumor will be growing?

Accepted Answer

Lung cancer most commonly begins in the cells lining the bronchi, which are the large air passages leading from the trachea to the lungs.

Question 6

During your dissection of a fish, what structure would you have to remove to see the gills?

Accepted Answer

The operculum is a bony flap covering the gills in fish, and it must be removed to view the gills.

Question 7

The many lamellae in the gills of fish improve respiratory efficiency by ______.

Accepted Answer

The many lamellae in the gills of fish increase the surface area available for gas exchange, thereby improving respiratory efficiency by allowing more oxygen to diffuse into the blood and more carbon dioxide to diffuse out.

Question 8

What respiratory adaptation was important for the invasion of land by arthropods?

Accepted Answer

The ability to close spiracles helps prevent water loss, which is crucial for arthropods living in terrestrial environments where desiccation is a risk.

Question 9

The close proximity of capillaries to the alveoli in lungs improve respiratory efficiency by ______.

Accepted Answer

The close proximity of capillaries to the alveoli decreases the distance for diffusion, allowing for more efficient gas exchange between the air in the alveoli and the blood in the capillaries.

Question 10

Humans cannot survive long at altitudes greater than 6000 m because ________.

Accepted Answer

At altitudes greater than 6000 m, the partial pressure of oxygen is significantly reduced, making it difficult for humans to obtain enough oxygen for survival.

Question 11

The North American pronghorn antelope can run almost as fast as a cheetah, but unlike the cheetah, can also sustain speeds of 30-40 mph for miles.The pronghorn is about the size of a large, domestic goat.You would predict the antelope to have a _____ than the goat.

Accepted Answer

The pronghorn's ability to sustain high speeds suggests it has a higher concentration of hemoglobin to efficiently transport oxygen to its muscles during prolonged exertion.

Question 12

Which dissolved gas cannot be transported by hemoglobin?

Accepted Answer

Nitrogen (N2) is not transported by hemoglobin because it is not reactive and does not bind to hemoglobin like oxygen, nitric oxide, or carbon monoxide.

Question 13

Soft-shelled turtles can remain submerged underwater for several hours without ventilating their lungs because ______.

Accepted Answer

Soft-shelled turtles can perform cutaneous respiration, which allows them to absorb oxygen through the soft lining of their throats, enabling them to stay submerged for extended periods without using their lungs.

Question 14

Most phyla of aquatic invertebrates have improved the rate of gas exchange by creating a water current over their respiratory surfaces, thereby _____.

Accepted Answer

Creating a water current over respiratory surfaces increases the concentration difference of gases, enhancing diffusion efficiency.

Question 15

Major evolutionary changes have resulted in anatomical and physiological adaptations that optimize the rate of gas exchange in animals by each of these factors except ________.

Accepted Answer

The diffusion constant for each gas is a physical property and cannot be altered by evolutionary changes. Evolutionary adaptations typically focus on decreasing diffusion distance, increasing surface area, and enhancing concentration gradients to optimize gas exchange.

Question 16

During an asthma attack, allergens trigger the release of histamine, which causes severe constriction of the __________________.

Accepted Answer

During an asthma attack, allergens cause the release of histamine, leading to the constriction of the bronchi, which are the air passages within the lungs.

Question 17

The large number of alveoli in lungs improve gas exchange by _____.

Accepted Answer

The large number of alveoli increases the surface area available for gas exchange, enhancing the efficiency of oxygen and carbon dioxide diffusion between the lungs and blood.

Question 18

Which of these animals uses positive pressure breathing?

Accepted Answer

Amphibians, such as frogs, use positive pressure breathing by actively pushing air into their lungs using their throat muscles.

Question 19

Tom is choking on a piece of steak that is stuck in his trachea, and he signals for his young son to call 911.It takes the paramedics four minutes to reach his house.Will this be in time to save Tom (and why), or will Tom already be dead (and why)?

Accepted Answer

Tom will be alive because the body has a reserve of oxygen bound to hemoglobin, which can sustain him for a few minutes even after he stops breathing.

Question 20

Which group of animals has one-way flow of air through its lungs, whereas all the others have tidal flow?

Accepted Answer

Birds have a unique respiratory system that allows for a one-way flow of air through their lungs, providing efficient gas exchange. This is different from the tidal flow system found in mammals, amphibians, and reptiles.

Quiz 48: The Respiratory System