wk 11 biology mock tests

Which of these is a true statement? a. In lung capillaries, carbonic acid breaks down to carbon dioxide and water. b. In tissue capillaries, carbonic acid breaks down to carbon dioxide and water. c. All of these statements are true. d. In lung capillaries, carbon dioxide combines with water to produce carbonic acid. e. In tissue capillaries, carbonic acid combines with hydrogen ions to form the carbonate ion.

a. In lung capillaries, carbonic acid breaks down to carbon dioxide and water.

Although having evolved independently, the tracheal tubes of mammals and insects are both supported by rigid tissues. The trachea of a mammal is supported by cartilage, and the tracheae of an insect are supported by chitin. What selective pressure most likely led to the convergent evolution of these respiratory structures? a. When air is the respiratory medium, there is a greater risk that the tracheal tubes will collapse. b. A decrease in environmental carbon dioxide made structural support necessary. c. Both mammals and insects have similar oxygen needs. d. None of the above is correct. e. Insects and mammals both keep their internal temperature constant.

a. When air is the respiratory medium, there is a greater risk that the tracheal tubes will collapse.

During most daily activities, the human respiration rate is most closely linked to the blood levels of ________. a. carbon dioxide b. nitrogen c. nitrogen monoxide d. carbon monoxide e. oxygen

a. carbon dioxide

During aerobic exercise, the partial pressure of oxygen in muscle cells will ________, thus the rate of diffusion of oxygen into the muscle tissue from the blood will ________. a. decrease; increase b. increase; decrease c. decrease; decrease d. increase; increase e. not change; also not change

a. decrease; increase

Countercurrent exchange in the fish gill helps to maximize ________. a. diffusion b. active transport c. muscle movement d. osmosis e. blood pressure

a. diffusion

To become bound to hemoglobin for transport in mammals, atmospheric molecules of oxygen must cross ________. a. five membranes—in and out of the cell lining the lung, in and out of the endothelial cell lining an alveolar capillary, and into the red blood cell—to bind with hemoglobin b. None of the above is correct. c. four membranes—in and out of the cell lining the lung, in and out of the endothelial cell lining an alveolar capillary—and then bind directly to hemoglobin, a protein dissolved in the plasma of the blood d. two membranes—in and out of the cell lining the lung—and then bind directly to hemoglobin, a protein dissolved in the plasma of the blood e. one membrane—that of the lining in the lungs—and then bind directly to hemoglobin, a protein dissolved in the plasma of the blood

a. five membranes—in and out of the cell lining the lung, in and out of the endothelial cell lining an alveolar capillary, and into the red blood cell—to bind with hemoglobin

A decrease of blood pH from 7.4 to 7.2 causes hemoglobin to ________. a. give up more of its oxygen molecules b. disassemble into subunits c. release all bound carbon dioxide molecules d. bind more oxygen molecules e. decrease its binding of H+

a. give up more of its oxygen molecules

Some human infants, especially those born prematurely, suffer serious respiratory failure because of ________. a. lung collapse due to inadequate production of surfactant b. mutations in the genes involved in lung formation c. None of the above is correct. d. the overproduction of surfactants e. the sudden change from the uterine environment to the air

a. lung collapse due to inadequate production of surfactant

The sun shining on a tidal pool during a hot day heats the water, causing some water to evaporate. Because the water has become warmer and saltier, ________. a. the oxygen content will decrease b. it will be better able to sustain aerobic organisms c. None of the above is correct. d. the carbon dioxide content will increase e. it will become more dense

a. the oxygen content will decrease

Atmospheric pressure at the summit of Mount Everest is about one third the pressure at sea level, which is 760 mm Hg. If oxygen makes up 21% of the atmosphere by volume, the partial pressure of oxygen (PO2) on Mount Everest is approximately ________. a. 255 mm Hg b. 53 mm Hg c. 157 mm Hg d. 760 mm Hg e. 137 mm Hg

b. 53 mm Hg

What is the optimum pH for human bodily fluids? a. 8.0 b. 7.4 c. 7.0 d. 6.0 e. 6.5

b. 7.4

Hyperventilation (rapid inhalation and exhalation) can result in respiratory alkalosis (increased blood pH). Why? a. More metabolic waste is released into the blood, thus reducing the pH. b. Rapid breathing depletes the blood of carbon dioxide, thus the blood pH increases. c. Excess production of carbon dioxide decreases the affinity of hemoglobin for oxygen. d. None of the above is correct. e. Hyperventilation results in inefficient gas exchange, and not enough oxygen is absorbed by the blood.

b. Rapid breathing depletes the blood of carbon dioxide, thus the blood pH increases.

Air enters the human lungs because a. although the pressures are the same inside and outside, the partial pressure of oxygen is lower within the lungs. b. atmospheric pressure is greater than the pressure inside the lungs. c. atmospheric pressure is less than the pressure inside the lungs. d. the residual air in the lungs causes the partial pressure of oxygen to be less than it is outside. e. the process of breathing pushes air into the lungs.

b. atmospheric pressure is greater than the pressure inside the lungs.

Which of these is incorrect concerning inspiration? a. The rib cage moves up and out. b. Pressure in the lungs decreases, and air comes rushing in. c. All of the above is correct. d. The diaphragm contracts and moves down. e. The force of the incoming air increases lung volume.

c. All of the above is correct.

Which of the following events would you predict as carbon dioxide is released from your muscles into the surrounding capillary bed? a. Arterial blood entering the capillaries will carry more oxygen. b. None of the above is correct. c. Oxygen delivery to muscle is increased when more carbon dioxide is produced by the muscle. d. The amount of oxygen in venous blood will increase. e. Because of the change in blood pH, the blood can carry more oxygen.

c. Oxygen delivery to muscle is increased when more carbon dioxide is produced by the muscle.

Which of the following statements is true? a. Air from the nasal cavity goes to the pharynx through the larynx. b. The bronchi branch into the tracheae. c. The bronchi branch into the bronchioles. d. Air from the pharynx goes to the larynx through the trachea. e. The larynx branches int two bronchi.

c. The bronchi branch into the bronchioles.

An oil-water mixture works as an insecticidal spray against mosquitoes and other insects because it ________. a. None of the above is correct. b. prevents gases from leaving the atmosphere c. blocks the openings into the tracheal system d. interferes with gas exchange across the capillaries e. clogs their bronchi

c. blocks the openings into the tracheal system

Most of the carbon dioxide produced by humans is ________. a. bound to hemoglobin b. simply dissolved in the plasma c. converted to bicarbonate ions d. transported in the erythrocytes as carbonic acid e. None of the above is correct.

c. converted to bicarbonate ions

Which of the following represents the correct flow of air into the lung of a mammal? a. trachea → tracheoles → bronchi → alveoli b. alveoli → tracheoles → bronchi → trachea c. larnyx → trachea → bronchi → bronchioles → alveoli d. trachea → bronchioles → bronchi → alveoli e. None of the above is correct.

c. larnyx → trachea → bronchi → bronchioles → alveoli

What would be the consequence 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 the mouth? This reversal of water flow would ________. a. None of the above is correct. b. instant death of the specimen c. reduce efficiency of gas exchange d. increase the efficiency of gas exchange e. change the exchange of gases in the body from carbon dioxide out and oxygen in to carbon dioxide in and oxygen out

c. reduce efficiency of gas exchange

When you hold your breath, which of the following blood gas changes first leads to the urge to breathe? a. falling CO2 b. None of the above is correct. c. rising CO2 d. falling O2 e. rising O2

c. rising CO2

Which of the following respiratory systems is not closely associated with a blood supply? a. the lungs of a vertebrate b. the skin of an earthworm c. the tracheal system of an insect d. All of the above are closely associated with a blood supply. e. the gills of a fish

c. the tracheal system of an insect

A person with a tidal volume of 450 mL (milliliters), a vital capacity of 4000 mL, and a residual volume of 1000 mL would have a potential total lung capacity of ________. a. 1450 mL b. 900 mL c. 4000 mL d. 5000 mL e. 4450 mL

d. 5000 mL

In humans, the respiratory control center a. is stimulated by hydrogen ion concentration. b. is located in the medulla oblongata. c. controls the rate of breathing. d. All of these are correct. e. is stimulated by carbon dioxide.

d. All of these are correct.

How has the avian lung adapted to the metabolic demands of flight? a. There is more dead space within the avian lung so that oxygen can be stored for future use. b. Airflow through the avian lung is bidirectional like in mammals. c. None of the above is correct. d. Gas exchange occurs during both inhalation and exhalation. e. Countercurrent circulation is present in the avian lung.

d. Gas exchange occurs during both inhalation and exhalation.

Which of the following statements comparing respiration in fish and in mammals is correct? a. A countercurrent exchange mechanism between the respiratory medium and blood flow is seen in mammals but not in fish. b. The respiratory medium for fish carries more oxygen than the respiratory medium of mammals. c. None of the above is correct. d. The movement of the respiratory medium in mammals is bidirectional, but in fish it is unidirectional. e. In blood, oxygen is primarily transported by plasma in fish, but by red blood cells in mammals.

d. The movement of the respiratory medium in mammals is bidirectional, but in fish it is unidirectional.

Compared with the interstitial fluid that bathes active muscle cells, blood reaching these cells in arterioles has a a. None of the above is correct. b. greater bicarbonate concentration. c. higher PCO2. d. higher PO2. e. lower pH.

d. higher PO2.

Carbon dioxide levels in the blood and cerebrospinal fluid affect pH. This enables the organism to sense a disturbance in gas levels as ________. a. stretch receptors in the lungs cause the medulla oblongata to speed up or slow breathing b. the brain directly measures and monitors oxygen levels and causes breathing changes accordingly c. the brain alters the pH of the cerebrospinal fluid to force the animal to retain more or less carbon dioxide d. the medulla oblongata, which is in contact with cerebrospinal fluid, monitors pH and uses this measure to control breathing e. None of the above is correct.

d. the medulla oblongata, which is in contact with cerebrospinal fluid, monitors pH and uses this measure to control breathing

If a molecule of CO2 released into the blood in your left toe is exhaled from your nose, it must pass through all of the following except a. the trachea. b. the right atrium. c. the right ventricle. d. the pulmonary vein. e. None of the above is correct.

d. the pulmonary vein.

When the air in a testing chamber is specially mixed so that its oxygen content is 10% and its overall air pressure is 400 mm Hg, then PO2 is ________. a. 82 mm Hg b. 68 mm Hg c. 400 mm Hg d. 4 mm Hg e. 40 mm Hg

e. 40 mm Hg

How much air is breathed in during quiet breathing? a. 8.000 ml b. 2.500 ml c. 1.500 ml d. 16.000 ml e. 500 ml

e. 500 ml

A rabbit taken from a meadow near sea level and moved to a meadow high on a mountainside would have some trouble breathing. Why? a. None of the above is correct. b. The partial pressure of oxygen in the air at high elevations is higher than at sea level. c. The percentage of oxygen in the air at high elevations is higher than at sea level. d. The percentage of oxygen in the air at high elevations is lower than at sea level. e. The partial pressure of oxygen in the air at high elevations is lower than at sea level.

e. The partial pressure of oxygen in the air at high elevations is lower than at sea level.

Consider the following reaction. CO2 + H2O <=> H2CO3 <=> HCO3- + H+ If the pH of the blood was decreased, then the ________. a. amount of oxygen in the blood will decrease b. amount of protons in the blood will increase c. bicarbonate in the blood would increase d. None of the above is correct. e. amount of carbon dioxide would increase

e. amount of carbon dioxide would increase

Under identical atmospheric conditions, freshwater ________. a. can hold 10-40 times more oxygen than air b. has less dissolved oxygen than seawater c. None of the above is correct. d. can hold 10-40 times more carbon dioxide than air e. has more dissolved oxygen than seawater

e. has more dissolved oxygen than seawater

The greatest difference in the concentration of respiratory gases is found in which of the following pairs of mammalian blood vessels? a. the veins from the right and left legs b. the pulmonary vein and the aorta c. None of the above is correct. d. the pulmonary artery and the inferior vena cava e. the pulmonary vein and the superior vena cava

e. the pulmonary vein and the superior vena cava

Countercurrent exchange is evident in the flow of ________. a. None of the above is correct. b. water across the skin of a frog and the blood flow within the ventricle of its heart c. air within the primary bronchi of a human and the blood within the pulmonary veins d. blood in the dorsal vessel of an insect and that of air within its tracheae e. water across the gills of a fish and the blood within those gills

e. water across the gills of a fish and the blood within those gills