Bio 182 Exam 2 Launchpad Questions

How many molecules of O2 can a single hemoglobin molecule carry when fully saturated? 1 2 4 8 16

4

What is meant by tidal ventilation? Air moves in a continuous, unidirectional flow through the lungs. Air moves into the lungs during inhalation and air moves out of the lungs during exhalation. None of the answer options are correct. The ventilation rate increases and decreases at regular intervals. Water is pumped back and forth across the respiratory system.

Air moves into the lungs during inhalation and air moves out of the lungs during exhalation.

Which of these choices increase(s) the amount of oxygen that a fish can extract from the surrounding seawater? All of these choices are correct. ventilation of the gills with the aid of an operculum very thin lamellae gills with a large surface area countercurrent exchange

All of these choices are correct.

Which of the statements is true regarding CO2 in the mammalian bloodstream? CO2 is mainly transported through the mammalian bloodstream in the form of bicarbonate ions or carbonic acid. All CO2 is transported through the mammalian bloodstream as a dissolved gas and is carried directly in the plasma. Unlike oxygen, CO2 is transported through the mammalian bloodstream by myoglobin. Like oxygen, CO2 is transported through the mammalian bloodstream via hemoglobin; however, CO2 binds to hemoglobin at amine groups rather than heme groups. In the mammalian bloodstream, CO2 is much less soluble than O2.

CO2 is mainly transported through the mammalian bloodstream in the form of bicarbonate ions or carbonic acid.

A researcher has introduced molecules of human myoglobin and hemoglobin into a solution containing oxygen. Which of the statements is true of human hemoglobin and myoglobin? Compared to human hemoglobin, human myoglobin will likely bind to oxygen molecules more quickly when introduced into the oxygen-containing solution. When introduced into an oxygen-containing solution, human hemoglobin will bind oxygen molecules more tightly than human myoglobin. When introduced into an oxygen-containing solution, human myoglobin and hemoglobin will behave similarly and will bind to the same number of oxygen molecules (with the same affinity). When introduced into an oxygen-containing solution, a single molecule of human myoglobin will bind to more oxygen molecules than a single human hemoglobin molecule will. Because myoglobin does not interact with oxygen molecules, only human hemoglobin will bind to oxygen molecules in this solution.

Compared to human hemoglobin, human myoglobin will likely bind to oxygen molecules more quickly when introduced into the oxygen-containing solution. If myoglobin and hemoglobin were both in an oxygen-containing solution, more oxygen molecules would bind to myoglobin because it has a higher affinity for oxygen.

A scientist is evaluating the hemoglobin in mountain goats compared to the hemoglobin in normal barnyard goats. How will the hemoglobin in these two goat species compare? Given that mountain goats tend to live at higher altitudes, hemoglobin in these goats will have more heme groups than the hemoglobin of barnyard goats. As these are both goat species, mountain goats and barnyard goats will have the same type of hemoglobin (with the same binding affinity for oxygen). Given that barnyard goats tend to live at lower altitudes, these goats will have hemoglobin with a greater oxygen-binding affinity compared to the hemoglobin of mountain goats. Given that barnyard goats tend to live at lower altitudes, hemoglobin in these goats will have more heme groups than the hemoglobin of mountain goats. Given that mountain goats tend to live at higher altitudes, these goats will have hemoglobin with a greater oxygen-binding affinity compared to the hemoglobin of barnyard goats.

Given that mountain goats tend to live at higher altitudes, these goats will have hemoglobin with a greater oxygen-binding affinity compared to the hemoglobin of barnyard goats. Because atmospheric pressure decreases with altitude, the partial pressure of oxygen is lower at higher altitudes. In order for adequate oxygen delivery to tissues, you would predict the hemoglobin in mountain goats to have a higher affinity for oxygen to offset the lower partial pressures.

What is the main benefit of having hemoglobin in the blood? It increases the amount of oxygen that can be carried in the blood. It keeps oxygen separated from carbon dioxide within the blood. It is an important source of iron for body cells. It increases the solubility of carbon dioxide in the blood plasma.

It increases the amount of oxygen that can be carried in the blood.

If heart rate decreases 30% followed by stroke volume decreasing 10%, then what effect do these decreases have on the total cardiac output? CO 100% = HR 70% (or 0.70) X SR 90% (or 0.90) CO 100% = 0.63 (or 63%) CO 100% - 63% = 37%.]] The cardiac output decreases by 40%. The cardiac output decreases by 3%. The cardiac output decreases by 20%. The cardiac output decreases by 30%. The cardiac output decreases by 37%. (Heart rate will decrease cardiac output by 30%, reducing it to 70% cardiac output. A 10% further decrease in stroke volume would decrease it another 7% for a total of 37% reduction in cardiac output 30+7 = 37). This is an alternate calculation:

The cardiac output decreases by 37%. (Heart rate will decrease cardiac output by 30%, reducing it to 70% cardiac output. A 10% further decrease in stroke volume would decrease it another 7% for a total of 37% reduction in cardiac output 30+7 = 37). This is an alternate calculation:

Which of the changes occurs during exhalation? Negative pressure in the lungs increases. The diaphragm relaxes and pushes up. The volume of the thoracic cavity increases. Intercostal muscles elevate the ribs. None of the answer options is correct.

The diaphragm relaxes and pushes up.

A researcher is studying a strain of mice that only incorporates 50% of the necessary iron into their hemoglobin molecules. Which of the statements is likely true regarding these mutant mice? The hemoglobin in these mutant mice will be unable to bind oxygen molecules, because iron-containing heme groups are responsible for the binding of oxygen to hemoglobin. The hemoglobin in these mutant mice will be able to bind half the number of oxygen molecules compared to the hemoglobin of normal or wild-type mice. Because oxygen cannot dissolve in the blood directly, no oxygen will be transported in the bloodstream of these mice. The hemoglobin in these mutant mice will be able to bind more oxygen molecules compared to the hemoglobin of normal or wild-type mice. There will be no difference between the amount of oxygen transported in the bloodstreams of these mutant mice compared to the amount transported in normal or wild-type mice.

The hemoglobin in these mutant mice will be able to bind half the number of oxygen molecules compared to the hemoglobin of normal or wild-type mice. Iron is required for the heme groups to form and bind oxygen. If there are fewer iron atoms, then the ability to bind oxygen decreases.

Which of the statements about insect respiration is true? Air enters the bodies of insects through the mouth. Air sacs in many insects hold air for use during the night. The insect respiratory system is composed of a series of branching tubes called tracheae. After diffusing through the walls of the tracheoles, oxygen is delivered to the body tissues by the circulatory system.

The insect respiratory system is composed of a series of branching tubes called tracheae.

A researcher is culturing cells that require oxygen to live in an incubator where the gas levels are carefully regulated. If the researcher observes that the pO2 in the incubator is 200 mmHg, what can the researcher deduce about the pO2 of her cells. No determination can be made regarding the pO2 in these cells. The pO2 of her cells is greater than 200 mmHg. The pO2 of her cells is less than or equal to 200 mmHg. The pO2 of her cells must be greater than 400 mmHg. None of the other answer options are correct.

The pO2 of her cells is less than or equal to 200 mmHg.

Which of the statements is true? The repolarization of the pacemaker cells following an action potential allows the heart to relax between contractions. The rapid depolarization phase of the action potential in pacemaker cells results from the influx of sodium through voltage-gated sodium channels. The resting membrane potential of cardiac pacemaker cells gradually becomes more negative on its own. Pacemaker cells repolarize by opening voltage-gated sodium channels.

The repolarization of the pacemaker cells following an action potential allows the heart to relax between contractions.

Which of the statements is accurate? Only Oxygen, not carbon dioxide, moves across the respiratory surface by diffusion. Ventilation increases the concentration of oxygen in the air on the inside of the respiratory surface. Larger, more complex animals and smaller, simpler animals rely on bulk flow and diffusion to deliver oxygen to their cells. The same amount of oxygen enters the blood through diffusion as is transported by circulation. Circulation requires a pump to generate pressure to drive flow, whereas ventilation does not.

The same amount of oxygen enters the blood through diffusion as is transported by circulation.

If the partial pressure of oxygen outside of a cell is 100 mmHg and the partial pressure of oxygen inside of a cell is 25 mmHg, which of the statements is correct? There will be a net diffusion of carbon dioxide into the cell. There will be no net diffusion of oxygen in either direction. There will be a net diffusion of oxygen from outside the cell to inside the cell. There will be a net diffusion of carbon dioxide out of the cell. There will be a net diffusion of oxygen from inside the cell to outside the cell.

There will be a net diffusion of oxygen from outside the cell to inside the cell. Gases will move from areas of higher partial pressure to areas of lower partial pressure for that gas. The partial pressure of oxygen is higher outside the cell, so oxygen will move into the cell.

A man has just learned that he has a blockage in one of his arteries. Which of the statements is true regarding this blockage? This blockage will likely decrease the resistance to flow in his circulatory system, and as a result, will increase the rate of blood flow. This blockage will likely increase the resistance to flow in his circulatory system, and as a result, will increase the rate of blood flow. This blockage will likely increase the resistance to flow in his circulatory system, and as a result, will decrease the rate of blood flow. This blockage will likely decrease the resistance to flow in his circulatory system, and as a result, will decrease the rate of blood flow.

This blockage will likely increase the resistance to flow in his circulatory system, and as a result, will decrease the rate of blood flow. The blockage will narrow the diameter of the vessel. The decreased diameter increases resistance. If you take the equation Q=P/R when R increases, the value of P/R decreases. Because Q=P/R, then Q flow will decrease as well.

The pacemaker of the mammalian heart is: an electrically charged region of the pulmonary vein. modulated by signals from the somatic nervous system. a group of fibers located between the atrium and the ventricle called the AV node. a group of specialized cardiac muscle cells that initiate the heartbeat.

a group of specialized cardiac muscle cells that initiate the heartbeat.

Osmosis requires: high Na+ concentrations. a nonpermeable membrane separating areas with Na+ ions from areas with Cl- ions. a semipermeable membrane separating areas of different solute concentrations. diffusion of salt through a semipermeable membrane.

a semipermeable membrane separating areas of different solute concentrations.

Which of these changes would increase the rate of blood flow through blood vessels? a. increasing the length and decreasing the diameter of the blood vessels b. decreasing the length and diameter of the blood vessels c. decreasing the length and increasing the diameter of the blood vessels d. decreasing the length and increasing the diameter of the blood vessels e. None of the answer options are correct.

c. decreasing the length and increasing the diameter of the blood vessels

Which of the choices describes the correct path of air through a bird's respiratory system? a. trachea, anterior air sacs, lungs, posterior air sacs, trachea b. trachea, lungs, posterior air sacs, anterior air sacs, trachea c. trachea, posterior air sacs, lungs, anterior air sacs, trachea d. trachea, anterior air sacs, posterior air sacs, lungs, trachea e. trachea, lungs, anterior air sacs, posterior air sacs, trachea

c. trachea, posterior air sacs, lungs, anterior air sacs, trachea

Which of the factors affects the rate of diffusion of a substance? viscosity concentration gradient direct supply of metabolic energy (ATP) presence of other solutes

concentration gradient

You may have heard of "polar bears," or people who choose to swim in the ocean during the winter months (often for charity). What happens to arterioles in the feet of a "polar bear" when they first step into ice cold water? a. The arterioles in the feet of the "polar bear" will neither constrict nor dilate, as vessel diameter is independent of changes in temperature. b. The arterioles in the feet of the "polar bear" will constrict completely, resulting in his or her feet being severely oxygen deprived. c. As feet placed in cold water will begin to shiver (and lose energy), the arterioles will dilate to provide cells of the "polar bear's" feet and toes with more O2 to be used during cellular respiration. d. Arterioles will likely constrict to prevent the "polar bear" from losing heat from his or her feet. e. Arterioles will likely dilate, providing more heat to the feet and toes.

d. Arterioles will likely constrict to prevent the "polar bear" from losing heat from his or her feet.

Which of these events occurs during systole? a. The atria fill with blood. b. Both atria contract. c. The left ventricle contracts. d. The ventricles fill with blood. e. Both ventricles contract.

e. Both ventricles contract.

True or false: The most important factor in the control of breathing is the amount of oxygen in the blood.

false

True or false: Ventilation only refers to the movement of oxygen into and out of air sacs or lungs. As a result, fish and other gilled animals do not experience ventilation.

false

Which of these animals has a heart in which oxygenated and deoxygenated blood mix? mammal bird frog fish human

frog

Which of these changes would increase the rate of oxygen diffusion from the air into the body cells of a flatworm? All of these choices are correct. increasing the surface area of the body increasing the partial pressure of oxygen inside the cells increasing the surface area of the body and the partial pressure of oxygen inside the cells increasing the thickness of the body wall

increasing the surface area of the body

Which of the choices describes the correct path of air through the human respiratory system? larynx, trachea, bronchi, bronchioles, alveoli trachea, larynx, bronchi, bronchioles, alveoli larynx, bronchioles, trachea, bronchi, alveoli bronchi, trachea, larynx, bronchioles, alveoli trachea, bronchi, larynx, bronchioles, alveoli

larynx, trachea, bronchi, bronchioles, alveoli

What percentage of oxygen in the air is typically extracted by the mammalian lung when an animal is resting? less than 25% 26-50% 51-75% 76-90% 91-100%

less than 25%

At the venous end of a capillary, the blood pressure is _____ the osmotic pressure and fluid _____ the blood vessel. lower than; moves into higher than; moves into equal to; remains within higher than; moves out of lower than; moves out of

lower than; moves into

Which of the choices is an example of bulk flow during gas exchange in vertebrates? movement of hemolymph throughout the body movement of oxygen from the lungs into the bloodstream movement of water past a respiratory surface movement of carbon dioxide from body cells into the bloodstream All of these choices are correct.

movement of water past a respiratory surface

What is the function of surfactant in the mammalian respiratory system? transport of oxygen capture and removal of inhaled foreign particles maintaining a moist surface reduction of surface tension in the fluid covering the alveoli

reduction of surface tension in the fluid covering the alveoli

During heavy exercise, blood pH will decrease. This will result in a shift to the ________ of the hemoglobin dissociation curve. right left

right During exercise there is an increase in carbon dioxide concentrations. Carbon dioxide is carried through the blood as protons and bicarbonate. The increase in proton concentration lowers blood pH and reduces hemoglobin's affinity for oxygen. This results in more oxygen being delivered to active cells.

In which of the heart chambers would deoxygenated blood be found? right atrium and left atrium right atrium and right ventricle left atrium and left ventricle right atrium and left ventricle left atrium and right ventricle

right atrium and right ventricle

Which of these organisms would be able to extract the greatest percentage of oxygen from their respiratory medium? sparrows salmon humans blue whales grasshoppers

salmon

Which of these chemicals will not pass through the phospholipid bilayer of a membrane? sodium ions molecular oxygen carbon dioxide

sodium ions

When stimulated by _____, arterioles supplying the digestive system ______, which decreases blood flow to digestive organs. parasympathetic nerves; constrict parasympathetic nerves; dilate sympathetic nerves; constrict sympathetic nerves; dilate ADH; constrict

sympathetic nerves; constrict During the flight-or-flight response, muscles demand more oxygen for increased activity. The sympathetic nervous system reduces blood flow to functions that are nonessential at the time, such as digestion.

A shift to the right in the hemoglobin dissociation curve means that: less O2 is released by hemoglobin to the body cells. the hemoglobin protein has denatured. the CO2 levels in the blood have decreased. the affinity of hemoglobin for O2 has decreased. the pH of the blood has increased.

the affinity of hemoglobin for O2 has decreased. A shift to the right would mean that at higher partial pressures of oxygen less oxygen is bound to hemoglobin. This reflects a decreased affinity for oxygen because the percent saturation is lower even at higher partial pressures of oxygen.

In the disease elephantiasis, lymph vessels become blocked because of infection with parasitic worms. Which of the processes would be impacted by this disease? the return of excess interstitial fluid to the bloodstream the generation of pressure to filter materials through the capillary walls the exchange of oxygen and other materials between the blood and body cells the diffusion of water and small molecules across the wall of the capillary the flow of water back into the capillaries by osmosis

the return of excess interstitial fluid to the bloodstream If the vessels were occupied by worms, then the amount of fluid that can enter the vessel would be reduced. The reduction of fluid entering the lymph vessel would result in decreased fluid returned into the circulatory system at the venae cava to the heart.

Dilated pupils, inhibited digestive activity, increased respiratory rate, and release of glucose from the liver are all signs of activity of: the sympathetic division of the autonomic system. both divisions of the autonomic nervous system. the parasympathetic division of the autonomic system. the somatic nervous system.

the sympathetic division of the autonomic system.

Why do cells in the airways of the lungs produce mucus? to decrease the surface tension (of liquids) in the lung to trap pathogens and guard against infection to move oxygen into solution so that it can diffuse into the bloodstream to prevent the diffusion of blood into the alveoli

to trap pathogens and guard against infection

True or false: As you read this sentence, you have breathed in and out. What you have just experienced is referred to as "gas exchange," where you have taken oxygen into your lungs and expelled carbon dioxide into the environment.

true

True or false: The binding of one O2 molecule to hemoglobin makes it easier for additional O2 molecules to bind.

true