BIOL102 chapter 42
Which statement about the gas exchange system in fish is correct? It enables oxygen to move from where its partial pressure is lower to where its partial pressure is higher. It relies on the parallel flow of blood and water in the gills It enables oxygen to diffuse from the water into the blood over the entire length of the gill capillaries. It relies on a higher partial pressure of oxygen in water than in air.
.It enables oxygen to diffuse from the water into the blood over the entire length of the gill capillaries.
How many capillary beds must a red blood cell pass through to move from an artery in the left arm to the left ventricle of the heart? 1 2 3 4
2
What is the theoretical cardiac output of a patient with a heart rate of 70 beats per minute and a stroke volume of 70 mL/beat? 1,000 mL/minute 4,900 mL/minute 2,800 mL/minute 1,400 mL/minute
4,900 mL/minute
What is the partial pressure of oxygen (PO2) when the air in a testing chamber is mixed so that its oxygen content is 10% and its overall air pressure is 400 mm Hg? 4 mm Hg 82 mm Hg 400 mm Hg 40 mm Hg
40 mm Hg
What is a person's total lung capacity if they have a tidal volume of 450 mL (milliliters), a vital capacity of 4,000 mL, and a residual volume of 1,000 mL? 4,450 mL 1,450 mL 4,000 mL 5,000 mL
5,000 mL
Atmospheric pressure at the summit of Mount Everest is about one third the pressure at sea level, which is 760 mm Hg. What is the partial pressure of oxygen (PO2) at the summit of Mount Everest if oxygen makes up 21% of the atmosphere by volume at both locations? 255 mm Hg 53 mm Hg 760 mm Hg 157 mm Hg
53 mm Hg
Chambers A and B are separated by a membrane permeable to substance X. The concentration of X is 5% in A and 15% in B. The volume of A is three times that of B. Which of the following will occur? Although diffusion is random, the result will be the net movement of X from B to A. There will be no net movement of X because the total amount of X is the same in A and B. Because diffusion is random, diffusion will take place without changing the concentration of X in either A or B. There will be no net movement of X because there is no energy available to transport X from B to A.
Although diffusion is random, the result will be the net movement of X from B to A.
Which lung structure is a tiny sac that functions as an interface between air and blood? Diaphragm. Capillary. Epithelium. Alveolus
Alveolus
__________ in carbon dioxide in your tissues leads to __________ in pH of cerebrospinal fluid and blood, which ultimately causes your breathing to speed up. Actually, it is the increase and decrease in oxygen, not carbon dioxide, that controls breathing. An increase, a drop An increase, a rise A decrease, a rise A decrease, a drop
An increase, a drop
Which of the following statements best describes an artery? Arteries carry blood away from capillaries. Arteries carry oxygenated blood. Arteries contain valves. Arteries carry blood away from the heart. Arteries have thin walls compared with veins.
Arteries carry blood away from the heart.
How is most carbon dioxide transported from tissues to the lungs? As protons (H+). As carbon dioxide gas. As carbonic acid. As bicarbonate ions (HCO3−).
As bicarbonate ions (HCO3−).
Why does the velocity of blood slow greatly as blood flows from arterioles into capillaries? Because the narrow capillaries offer great resistance to blood flow. Because capillary beds have a total cross-sectional area much greater than the total cross-sectional area of the arterioles. Because capillary beds are the site of nutrient and oxygen delivery to tissues.
Because capillary beds have a total cross-sectional area much greater than the total cross-sectional area of the arterioles.
Select the correct statement about capillary beds. Capillary beds join arteries and veins. Capillary beds have a total cross-sectional area much smaller than the total cross-sectional area of major arteries. Capillary beds are the site of nutrient and oxygen delivery to tissues.
Capillary beds are the site of nutrient and oxygen delivery to tissues.
Which statement best describes how diving mammals are different than mammals that are not adapted for diving? Diving mammals can store more oxygen in their muscles Diving mammals have larger lungs Diving mammals always keep blood flowing to their lungs during a dive Diving mammals have smaller blood vessels
Diving mammals can store more oxygen in their muscles
True or false? The circulatory systems of land-dwelling vertebrates are composed of two pumping circuits: the systemic circulation, which is a lower-pressure circuit to the lung, and the pulmonary circulation, which is a higher-pressure circuit to the rest of the body.
False
Which of the following is an adaptation of the avian lung that best helps meet the metabolic demands of flight? Airflow through the avian lung is bidirectional like in mammals. Countercurrent circulation is present in the avian lung. Gas exchange occurs during both inhalation and exhalation. There is more dead space within the avian lung so that oxygen can be stored for future use.
Gas exchange occurs during both inhalation and exhalation.
A researcher investigating the effect of temperature on hemoglobin saturation collected the data represented in the graph. Which of the following claims is most consistent with the data? Colder blood temperature results in greater dissociation of oxygen and hemoglobin. The greatest delivery of oxygen from the blood to the surrounding tissues occurs at 37°C. Increasing blood pH results in more oxygen unloading in tissues. Hemoglobin has a lower affinity for oxygen under high temperature conditions.
Hemoglobin has a lower affinity for oxygen under high temperature conditions.
Which statement about lipoproteins is correct? High-density lipoproteins are a form of cholesterol considered the "good" type to have in blood plasma. Low-density lipoproteins are the principal component of atherosclerotic plaques. High-density lipoproteins are cholesterol transporters in the blood.
High-density lipoproteins are cholesterol transporters in the blood.
Which letter indicates the vessels in which blood pressure is the lowest? f g h i
I
Which of the following mechanisms are used to regulate blood pressure in the closed circulatory system of vertebrates? I)changing the strength of heart contraction II)constricting and relaxing smooth muscle in the walls of arterioles III)opening or closing precapillary sphincters only I and II only I and III only II and IIII, I, II, and III
I, II, and III
Which of the following statements regarding the mammalian heart is correct? Blood is pumped from the heart via the atria. Oxygen-loaded blood moves only through the right side of the heart. When the right atrium contracts, it forces blood into the left atrium. In the adult heart, blood in the right chambers of the heart cannot enter the left chambers without passing through the lungs. Blood arrives at the heart via the ventricles.
In the adult heart, blood in the right chambers of the heart cannot enter the left chambers without passing through the lungs.
How are gases transported in insect bodies? In tracheal systems In open circulatory systems In closed circulatory systems
In tracheal systems
What is the function of a circulatory system? It acts as a reservoir for the storage of blood. It brings a transport liquid into close contact with all cells in the body. It exchanges oxygen and carbon dioxide with the outside air. It is the site of blood cell production.
It brings a transport liquid into close contact with all cells in the body.
Which statement best describes what happens to the carbon dioxide produced by humans? It is converted to bicarbonate ions. It is transported in the erythrocytes as carbonic acid. It is bound to hemoglobin. It is simply dissolved in the plasma.
It is converted to bicarbonate ions.
What is the function of the left ventricle? It pumps deoxygenated blood to the lungs via the pulmonary circulation. It receives deoxygenated blood from the lungs. It pumps oxygenated blood around the body via the systemic circulation. It receives oxygenated blood from the lungs.
It pumps oxygenated blood around the body via the systemic circulation.
Which of the following statements about human blood vessels is correct? Veins transport blood from the heart to the capillaries. Arteries carry blood toward the atria of the heart. Pulmonary veins carry oxygen-rich blood to the heart. The pulmonary artery carries oxygen-rich blood from the lungs. Arteries carry oxygenated blood; veins carry oxygen-poor blood.
Pulmonary veins carry oxygen-rich blood to the heart.
Which event occurs first during atrial and ventricular diastole? Blood flows into the relaxed atria while the ventricles contract. The atria and ventricles are relaxed, and blood flows into the atria. The atria and ventricles contract simultaneously. The atria contract while blood flows into the relaxed ventricles.
The atria and ventricles are relaxed, and blood flows into the atria.
Which of the following statements about the oxygen-hemoglobin interaction is true? The binding of one oxygen molecule to hemoglobin stimulates the binding of other oxygen molecules. The oxygen-hemoglobin dissociation curve is exponential, which means that hemoglobin can respond quickly to small changes in oxygen demand. The binding of one oxygen molecule to hemoglobin stimulates the unloading of the oxygen molecules that are already bound. Each hemoglobin molecule can bind one oxygen molecule.
The binding of one oxygen molecule to hemoglobin stimulates the binding of other oxygen molecules.
Why do the circulatory systems of land vertebrates have separate circuits to the lungs and to the rest of the body? Blood is pumped to the lungs to be oxygenated before being pumped to the rest of the body. The circuits increase the amount of surface area available for the diffusion of gases and nutrients in the body. Land vertebrates are bigger and require more tubing to reach all areas of the body. The large decrease in blood pressure as blood moves through the lungs may prevent efficient circulation through the rest of the body.
The large decrease in blood pressure as blood moves through the lungs may prevent efficient circulation through the rest of the body.
Which of the following statements correctly compares respiration in fish and in mammals? The movement of the respiratory medium in mammals is bidirectional, but in fish it is unidirectional. The respiratory medium for fish carries more oxygen than the respiratory medium of mammals. In blood, oxygen is primarily transported by plasma in fish, but by red blood cells in mammals. A countercurrent exchange mechanism between the respiratory medium and blood flow is seen in mammals but not in fish.
The movement of the respiratory medium in mammals is bidirectional, but in fish it is unidirectional.
Which statement about oxygen in fish gills is correct? The partial pressure of oxygen in blood increases as it flows through gill capillaries. Oxygen diffuses from the bloodstream into the water along the entire length of the capillaries. The partial pressure of oxygen in the blood is lowest where the partial pressure of oxygen in the water is highest. The partial pressure of oxygen is greater in the blood than in the adjacent water.
The partial pressure of oxygen in blood increases as it flows through gill capillaries.
A rabbit taken from a meadow near sea level and moved to a meadow high on a mountainside would have some trouble getting adequate oxygen delivery. Which statement best explains why this would occur? The partial pressure of oxygen in the air at high elevations is lower than at sea level. The partial pressure of oxygen in the air at high elevations is higher than at sea level. The percentage of oxygen in the air at high elevations is higher than at sea level. The percentage of oxygen in the air at high elevations is lower than at sea level.
The partial pressure of oxygen in the air at high elevations is lower than at sea level.
Select the correct statement about the three-chambered hearts of amphibians and nonbird reptiles. Pulmonary and systemic blood fully mixes in the ventricle of a three-chambered heart. The three-chambered hearts of amphibians and nonbird reptiles are facultative, allowing variation in blood flow through the heart. The three-chambered heart is inferior to the four-chambered hearts of birds and mammals, limiting the evolutionary success of amphibians and nonbird reptiles.
The three-chambered hearts of amphibians and nonbird reptiles are facultative, allowing variation in blood flow through the heart.
Which of the following features of the mammalian circulatory system helps to prevent damage to capillaries from high arterial blood pressure? Capillary beds have the thickest walls of any blood vessel to resist these high pressures. The total cross-sectional diameter of the blood vessels increases with progression from artery to arteriole to capillary, leading to a reduced blood pressure. Fluid loss from the arteries is high enough that pressure drops off significantly by the time blood reaches the capillaries. Blood flow through the capillaries is essentially frictionless, and this reduces the amount of pressure on their walls.
The total cross-sectional diameter of the blood vessels increases with progression from artery to arteriole to capillary, leading to a reduced blood pressure.
Which event of the cardiac cycle occurs when systolic blood pressure is measured? he atria contract while blood flows into the relaxed ventricles. The atria and ventricles contract simultaneously. The ventricles contract, carrying blood into the aorta, and blood flows into the relaxed atria. The atria and ventricles are relaxed, and blood flows into the atria
The ventricles contract, carrying blood into the aorta, and blood flows into the relaxed atria.
While jogging, a person has a stroke volume of 130 mL/beat and a heart rate of 120 beats per minute. Their resting stroke volume is 70 mL/beat and resting heart rate is 60 beats per minute. Which answer best describes the effect of jogging on the person's cardiac output? Their cardiac output increased from 4,200 mL/minute to 15,600 mL/minute when jogging. During exercise, their cardiac output decreased by 11,400 mL/minute. Their cardiac output did not change. Only their respiratory rate changed. During rest, their cardiac output increased by 60 mL/beat.
Their cardiac output increased from 4,200 mL/minute to 15,600 mL/minute when jogging.
The partial pressure of oxygen at a particular point in the bloodstream is 100 mm Hg. Under what circumstance will there be a net diffusion of oxygen from the water into the bloodstream at this location? There will be a net diffusion of oxygen from the water into the bloodstream regardless of the partial pressure of oxygen in the water. There will be a net diffusion of oxygen from the water into the bloodstream only if the partial pressure of oxygen in the water is less than 100 mm Hg. There will be a net diffusion of oxygen from the water into the bloodstream only if the partial pressure of oxygen in the water is greater than 100 mm Hg. There will be a net diffusion of oxygen from the water into the bloodstream only if the partial pressure of oxygen in the water is equal to 100 mm Hg.
There will be a net diffusion of oxygen from the water into the bloodstream only if the partial pressure of oxygen in the water is greater than 100 mm Hg.
Which of the following statements about blood circulation in the body is true? Deoxygenated blood flowing through the pulmonary veins is carried to the right atrium. Valves prevent the backflow of blood into the atria and ventricles. During one cardiac cycle, the two ventricles contract first, and then the two atria contract. As the right ventricle contracts, it sends oxygenated blood through the aorta to all tissues of the body.
Valves prevent the backflow of blood into the atria and ventricles.
Although having evolved independently, the tracheal tubes of mammals and insects are both supported by rigid tissues. The trachea of a mammal are supported by cartilage, and the tracheae of an insect are supported by chitin. Which of the following is a selective pressure that most likely led to the convergent evolution of these respiratory structures? Both mammals and insects have similar oxygen needs. A decrease in environmental carbon dioxide made structural support necessary. Insects and mammals both keep their internal temperature constant. When breathing air, there is a risk that trachea and tracheal tubes will collapse.
When breathing air, there is a risk that trachea and tracheal tubes will collapse.
Which letter indicates systolic pressure? a b c i
a
Stroke occurs when __________. the pacemaker of the heart becomes defective, producing an irregular heartbeat a blood clot dislodges from a vein and moves into the lung, where it blocks a pulmonary artery a blood clot enters and blocks one of the coronary arteries a blood clot enters the cerebral circulation, blocking an artery and causing the death of brain tissue the walls of an artery in the leg accumulate deposits and lose their flexibility and elasticity
a blood clot enters the cerebral circulation, blocking an artery and causing the death of brain tissue
Which type of circulatory system is most likely present in organisms with a circulating body fluid that is distinct from the fluid that directly surrounds the body's cells? a closed circulatory system an open circulatory system a gastrovascular cavity branched tracheae
a closed circulatory system
By picking up hydrogen ions, hemoglobin prevents the blood from becoming too _____. acidic basic thick low in oxygen concentration red
acidic
Which of the following is a normal event in the process of blood clotting? conversion of fibrin to fibrinogen synthesis of hemoglobin activation of prothrombin to thrombin production of erythropoietin
activation of prothrombin to thrombin
Most carbon dioxide is carried from the body tissues to the lungs _____. as bicarbonate ions (HCO3 -) combined with hemoglobin by the trachea as hydrogen ions (H+) dissolved in blood plasma
as bicarbonate ions (HCO3 -)
Which letter indicates diastolic pressure? a b c i
b
A decrease of blood pH from 7.4 to 7.2 would cause hemoglobin to ________. bind fewer oxygen molecules bind more oxygen molecules release all bound carbon dioxide molecules bind fewer H+ ions
bind fewer oxygen molecules
Which of the following indicates a diagnosis of hypertension in adults? measurement of the LDL/HDL ratio in peripheral blood measurement of fatty deposits on the endothelium of arteries blood pressure being greater than 140 mm Hg systolic and/or greater than 90 mm Hg diastolic percentage of blood volume made up of platelets
blood pressure being greater than 140 mm Hg systolic and/or greater than 90 mm Hg diastolic
The smallest airway through which inspired air passes before gas exchange occurs in the mammalian lungs is the __________. trachea bronchiole larynx bronchus pharynx
bronchiole
The human respiration rate is most closely correlated to the blood levels of which compound during most daily activities? carbon monoxide oxygen nitrogen carbon dioxide
carbon dioxide
In the blood most of the oxygen that will be used in cellular respiration is carried from the lungs to the body tissues _____. as bicarbonate ions (HCO3 -) combined with hemoglobin by the trachea water (H2O) dissolved in blood plasma
combined with hemoglobin
Which letter indicates the arteries? c d e f
d
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 ________. increase; decrease not change; also not change decrease; decrease decrease; increase
decrease; increase
Countercurrent exchange in the fish gill helps to maximize ________. diffusion osmosis blood pressure active transport
diffusion
Damage to the SA node in humans is most likely to result in a ________. blockage of conductance between the bundle branches and the Purkinje fibers negative effect on peripheral resistance disruption on the rate and timing of cardiac muscle contractions direct effect on blood pressure monitors in the aorta
disruption on the rate and timing of cardiac muscle contractions
Which letter indicates the vessels in which blood velocity is decreasing the most due to an increase in the total combined cross-sectional area of those vessels? d e g h
e
Which of the following organisms has no specialized respiratory structures? See Concept 42.5 (Page) ants crabs alligators salmon earthworms
earthworms
Which letter indicates the vessels in which blood travels the most slowly? e f g h
f
True or false? The driving force for the unloading of oxygen from hemoglobin into tissues is the difference in PCO2 levels between the blood and body tissues.
false
True or false? The pressure inside the human chest cavity is always positive, so the lungs stay relatively inflated even upon exhalation.
false
Which of the following are the only vertebrates in which blood flows directly from respiratory organs to body tissues without first returning to the heart? amphibians mammals reptiles fishes
fishes
Which biological membranes must atmospheric molecules of oxygen cross to become bound to hemoglobin for transport in mammals? two membranes (in and out of the cell lining the lung) four membranes (in and out of the cell lining the lung, in and out of the endothelial cell lining an alveolar capillary) 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) one membrane (the lining in the lungs)
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)
Which of the following examples illustrates the process of countercurrent exchange? flow of water across the gills of a fish and the blood within those gills flow of water across the skin of a frog and the blood flow within the ventricle of its heart flow of air within the primary bronchi of a human and the blood within the pulmonary veins flow of blood in the dorsal vessel of an insect and that of air within its tracheae
flow of water across the gills of a fish and the blood within those gills
Which of the following would an organism need to adjust blood pressure independently in the blood vessels of the gas-exchange surface and in the blood vessels of the general body circulation? open circulatory system four-chambered heart two-chambered heart hemocoel
four-chambered heart
In which of the following organisms does blood flow from the pulmocutaneous circuit to the heart before circulating through the rest of the body? annelids insects fishes frogs
frogs
Which letter indicates the venules? f g h i
g
Which one of the following organisms likely has the highest systolic pressure in its aorta? giraffe human mouse hippopotamus
giraffe
In which of the following animals are the blood and the interstitial fluid considered to be the same body fluid? fishes grasshoppers jellyfish and cnidarians dogs sparrows
grasshoppers
Which letter indicates the vessels in which blood velocity is increasingthe most due to a decrease in the total combined cross-sectional area of those vessels? d e g h
h
Pulse is a direct measure of cardiac output. stroke volume. blood pressure. heart rate
heart rate
Compared with the interstitial fluid that bathes active muscle cells, blood reaching these cells in arterioles has a greater bicarbonate concentration. higher PO2. lower pHp higher PCO2
higher PO2.
The amount of oxygen bound to hemoglobin _____. See Concept 42.7 (Page) is called the Bohr shift increases with increasing acidity at the tissue level increases as the pH of tissues decreases decreases in the presence of high concentrations of oxygen increases in the presence of high concentrations of oxygen
increases in the presence of high concentrations of oxygen
From the capillaries of the abdominal organs and hind limbs, blood flows to the _____. right atrium left atrium aorta capillaries of the lungs inferior vena cava
inferior vena cava
Organisms belonging to a species with a high resting cardiac output are most likely to have which of the following characteristics? wide-diameter veins small compact bodies large distance between its heart and its brain a relatively inactive lifestyle
large distance between its heart and its brain
Which of the following represents the correct flow of air into the lung of a mammal? trachea →→ tracheoles →→ bronchi →→ alveoli trachea →→ bronchioles →→ bronchi →→ alveoli larnyx →→ trachea →→ bronchi →→ bronchioles →→ alveoli alveoli →→ tracheoles →→ bronchi →→ trachea
larnyx →→ trachea →→ bronchi →→ bronchioles →→ alveoli
Voice sounds are produced by the _____. trachea diaphragm bronchioles larynx lungs
larynx
From the pulmonary veins, blood flows to the _____. right atrium left atrium aorta capillaries of the lungs inferior vena cava
left atrium
Blood returning to the mammalian heart in a pulmonary vein drains first into the left ventricle. right ventricle. right atrium. left atrium.
left atrium.
Some human infants, especially those born prematurely, suffer serious respiratory failure because of lung collapse due to inadequate production of surfactant the sudden change from the uterine environment to the air mutations in the genes involved in lung formation the overproduction of surfactants
lung collapse due to inadequate production of surfactant
The primary functions of the _____ are to warm, filter, and humidify air. lungs trachea bronchus nasal cavity alveoli
nasal cavity
Atrial systole ________. only occurs in the left heart chambers pumps blood to the aorta refers to the relaxation of the cardiac muscle occurs at the same time as ventricular diastole
occurs at the same time as ventricular diastole
As a property of enzymes, cooperativity refers to catalysis that consumes the enzyme. two different enzymes using the same substrate. one enzyme acting on two different substrates. one enzyme subunit altering the behavior of others.
one enzyme subunit altering the behavior of others.
Cellular respiration takes place in specialized organelles called chloroplasts. produces CO2 and ATP. uses O2 and CO2 as raw materials. synthesizes sugars from CO2 and H2O.
produces CO2 and ATP.
Blood returns to the heart via the _____. aorta pulmonary arteries pulmonary veins aorta and pulmonary arteries aorta and pulmonary veins
pulmonary veins
An advantage of gas exchange in water, compared with gas exchange in air, is that __________. the respiratory surface does not have to be as extensive in water water is easier to move over the respiratory surface ventilation requires less energy in water water usually contains a higher concentration of oxygen than air respiratory surfaces remain moist
respiratory surfaces remain moist
From the superior vena cava, blood flows to the _____. right atrium left atrium aorta capillaries of the lungs inferior vena cava
right atrium
When you hold your breath, which of the following blood gas changes first leads to the urge to breathe? rising O2 falling O2 falling CO2 rising CO2
rising CO2
Which of the following results in the greatest blood pressure in the mammalian aorta? diastole of the right atrium diastole of the right ventricle systole of the left atrium systole of the left ventricle
systole of the left ventricle
Consider the following reaction. Which of the following would happen if the pH of the blood was decreased?CO2 + H2O ⇐ H2CO3 ⇐ HCO3- + H+ the bicarbonate concentration in the blood would increase the amount of protons in the blood will increase the amount of oxygen in the blood will decrease the amount of carbon dioxide would increase
the amount of carbon dioxide would increase
A paleontologist discovers the fossilized heart of an extinct animal. The evidence indicates that the organism's heart was large, was well-formed, and had four chambers, with no connection between the right and left sides. Which of the following conclusions is best supported by these observations? the animal had evolved from birds the animal had little to no need to regulate blood pressure the animal was endothermic and had a high metabolic rate the animal was most closely related to alligators and crocodiles
the animal was endothermic and had a high metabolic rate
Which of the following would be the consequence if the direction of water flow over the gills of a fish was reversed, moving water inward past the operculum, past the gills, then out the mouth? the efficiency of gas exchange would be reduced the efficiency of gas exchange would increase the thickness of the blood would decrease the thickness of the blood would increase
the efficiency of gas exchange would be reduced
Which of the following best describes how an organism senses a disturbance in gas levels? the brain alters the pH of the cerebrospinal fluid to force the animal to retain more or less carbon dioxide the medulla oblongata, which is in contact with cerebrospinal fluid, monitors pH and uses this measure to control breathing stretch receptors in the lungs cause the medulla oblongata to speed up or slow breathing the brain directly measures and monitors oxygen levels and causes breathing changes accordingly
the medulla oblongata, which is in contact with cerebrospinal fluid, monitors pH and uses this measure to control breathing
One feature that amphibians and humans have in common is the number of heart chambers. a low blood pressure in the systemic circuit. the number of circuits for circulation. a complete separation of circuits for circulation.
the number of circuits for circulation.
The sun shining on a tidal pool during a hot day heats the water, causing some water to evaporate. Which of the following is most likely to occur because the water has become warmer and saltier? it will be better able to sustain aerobic organisms the carbon dioxide content will increase it will become more dense the oxygen content will decrease
the oxygen content will decrease
Which of the following is most analogous in structure and function to the circulatory systems of bony fishes, rays, and sharks? the three-chambered heart of reptiles, where oxygenated and non-oxygenated blood mix in the ventricles the circulatory systems of sponges, where gas exchange in all cells occurs directly with the external environment the portal systems of mammals, where two capillary beds occur sequentially, without passage of blood through a pumping chamber the four-chambered heart of humans, where non-oxygenated blood is pumped to the lungs from one ventricle and oxygenated blood is pumped to the body from another ventricle
the portal systems of mammals, where two capillary beds occur sequentially, without passage of blood through a pumping chamber
The greatest difference in the concentration of respiratory gases is found in which of the following pairs of mammalian blood vessels? the pulmonary vein and the superior vena cava the veins from the right and left legs the pulmonary vein and the aorta the pulmonary artery and the inferior vena cava
the pulmonary vein and the superior vena cava
A molecule of CO2 released into the blood in your left toe can be exhaled from your nose without passing through which of the following structures? the pulmonary vein. the right atrium .the trachea. the right ventricle
the pulmonary vein.
An electrocardiogram (ECG) provides information about ________. the rhythm of heart contractions the amount of oxygen in the blood as it leaves the heart the pressure of blood in the heart chambers the speed of blood flow through the blood vessels
the rhythm of heart contractions
Circulatory systems help to overcome which of the following physiological challenges? the slow rate at which diffusion occurs over large distances temperature differences between the lungs and the active tissue the need to cushion animals from trauma the problem of communication systems involving only the nervous system
the slow rate at which diffusion occurs over large distances
The velocity of blood flow lowest in capillaries because ________. the diastolic blood pressure is too low to deliver blood to the capillaries at a high flow rate the systemic capillaries are supplied by the left ventricle, which has a lower cardiac output than the right ventricle the capillaries have internal valves that slow the flow of blood the total cross-sectional area is greater in the capillaries than in any other part of the circulatory system
the total cross-sectional area is greater in the capillaries than in any other part of the circulatory system
Which of the following respiratory systems is independent from a fluid-based circulatory system? the gills of a fish the lungs of a vertebrate the tracheal system of an insect the skin of an earthworm
the tracheal system of an insect
True or false? The lungs of humans form from the embryonic foregut.
true
Which of the following is the correct sequence of blood flow in birds and mammals? left ventricle →→ aorta →→ lungs →→ systemic circulation vena cava →→ right atrium →→ right ventricle →→ pulmonary vein pulmonary vein →→ left atrium →→ left ventricle →→ pulmonary circuit vena cava →→ right atrium →→ right ventricle →→ pulmonary artery
vena cava →→ right atrium →→ right ventricle →→ pulmonary artery
