Exam 2 - Mastering Biology

Would phenobarbital, atropine, or serotonin have blocked naloxone binding at a concentration of 10-5 M? a. All of these drugs would have blocked naloxone binding at 10-5 M. b. It is impossible to tell from the data. c. Phenobarbital would have blocked naloxone binding at 10-5 M, but atropine and serotonin would not have. d. None of these drugs would have blocked naloxone binding at 10-5 M.

d. None of these drugs would have blocked naloxone binding at 10-5 M.

An action potential moves along an axon due to the sequential opening of voltage-gated Na+ channels. The diagram below shows voltage-gated Na+ channels separated by a short distance in the plasma membrane of an axon. Initially (left panel), only channel (a) is open. Within a very short time (right panel), channel (b) also opens. Which statement correctly describes what causes the second voltage-gated Na+ channel to open? a. As Na+ ions enter the cell through the first channel, they spread out from the channel. When these Na+ ions reach the second channel, it opens. b. As Na+ ions enter the cell through the first channel, Na+ ions outside the cell move toward the open Na+ channel. When the concentration of Na+ ions near the second channel becomes low enough, the second channel opens. c. After the first channel opens, the movement of Na+ ions (both inside and outside the cell) alters the Na+ ion distribution across the

d. After the first channel opens, the movement of many types of ions (both inside and outside the cell) alters the distribution of charges near the second channel, causing it to open.

The graph below shows the hemoglobin dissociation curves (also called equilibrium curves) for normal blood pH (the blue curve) and two other conditions. Given what you know about the Bohr shift, what is the difference in O2 saturation of hemoglobin in the lungs versus hemoglobin in exercising tissues, as represented on this graph? Keep in mind that the pH of blood in the lungs is not the same as the pH of blood in exercising tissues. Express your answer in percent, but do not include the percent sign in your answer.

57 (Do not include the percent sign in the answer when typed)

The data from this experiment are expressed using scientific notation: a numerical factor times a power of 10. Remember that a negative power of 10 means a number less than 1. For example, the concentration 10-1 M (molar) can also be written as 0.1 M. What is the lowest concentration of morphine that blocked naloxone binding, in standard notation? a. 0.000000006 M b. 0.00000002 M c. 0.000006 M d. 0.000009 M

a. 0.000000006 M

Skeletal muscle contraction is a graded process, meaning that you can voluntarily alter the strength and extent of contraction of your skeletal muscles, such as your biceps. Increasing the strength and extent of contraction occurs by increasing the number of muscle cells that receive action potentials. In addition, increasing the number of action potentials sent to a muscle cell can also increase muscle tension, as shown in the graph.A tiny muscle "twitch" is caused by a single action potential.Two or more closely spaced action potentials have an additive effect because the muscle does not have sufficient time to relax between action potentials.A long series of closely spaced action potentials results in a sustained, maximum contraction, called tetanus. Which of the following statements correctly describes why a series of closely spaced action potentials causes a sustained contraction rather than a series of clos

a. When a series of action potentials is closely spaced, there is not sufficient time for Ca2+ uptake into the sarcoplasmic reticulum between action potentials, and Ca2+ remains bound to troponin throughout the series

Which letter indicates systolic pressure? a. a b. b c. c d. i

a. a

Which of the following best describes an artery? a. arteries can carry blood away from the heart b. arteries contain valves c. arteries have thin walls compared with veins d. arteries carry oxygenated blood e. arteries carry blood away from capillaries

a. arteries can carry blood away from the heart

What could explain the higher energy cost of flying compared with that of swimming? a. flying animals use more energy to overcome gravity than do swimming animals b. smaller animals have higher energy costs than larger ones, and flying animals are smaller than swimming animals c. friction is more of a problem for flying animals than for swimming animals d. energy cost is less important to flying animals than to swimming animals. Because of this, there has not been much natural selection for lower energy cost in flying animals

a. flying animals use more energy to overcome gravity than do swimming animals

Which statement regarding the mammalian heart is correct? a. in the adult heart, blood in the right chambers of the heart cannot enter the left chambers without passing through the lungs b. blood arrives at the heart via the ventricles c. when the right atrium contracts, it forces blood to the left atrium d. oxygen-loaded blood moves only through he right of the heart e. blood is pumped from the heart via the atria

a. in the adult heart, blood in the right chambers of the heart cannot enter the left chambers without passing through the lungs

When an inactive person becomes active, the percentage of slow muscle fibers ________________, and the percentage of fast muscle fibers _________________. a. increase; decreases b. decreases; increases c. increases; increases d. decreases; decreases

a. increase; decreases

What is the function of a circulatory system? a. it brings a transport liquid into close contact wit all cells in the body b. it acts as a reservoir for the storage of blood c. it exchanges oxygen and carbon dioxide with the outside air d. it is the site of blood cell production

a. it brings a transport liquid into close contact wit all cells in the body

What is the function of the left ventricle? a. it pumps oxygenated blood around the body via the systemic circulation b. it receives oxygenated blood from the lungs c. it pumps deoxygenated blood to the lungs via the pulmonary circulation d. it receives deoxygenated blood from the lungs

a. it pumps oxygenated blood around the body via the systemic circulation

What is the best explanation for the fact that the two histograms overlap as much as they do? a. many factors in addition to PCSK9 enzyme activity affected plasma LDL levels b. the sample size of the study group is much smaller than the sample size of the control group c. PCSK9 enzyme activity varies widely among individuals with an inactivating mutation in only one copy of the PCSK9 gene d. plasma LDL levels are hard to measure precisely, so the histograms show the spread around the true value

a. many factors in addition to PCSK9 enzyme activity affected plasma LDL levels

Which drugs blocked naloxone binding in this experiment? a. morphine, methadone, and levorphanol only b. morphine, methadone, levorphanol, phenobarbital, atropine, and serotonin c. morphine and methadone only d. morphine, methadone, and serotonin only

a. morphine, methadone, and levorphanol only

What result did the researchers obtain for atropine, in standard notation? a. no effect at 0.0001 M b. no effect at 0.0004 M c. no effect at 0.001 M d. no effect at 10,000 M

a. no effect at 0.0001 M

Based on these two histograms, what conclusion can you draw? a. on average, individuals with an inactivating mutation in the PCSK9 gene have lower plasma LDL levels than wild-type individuals b. the plasma LDL levels of individuals with an inactivation mutation in the PCSK9 gene c. on average, individuals with increased PCSK9 enzyme activity have higher plasma LDL levels than wild-type individuals d. on average, individuals with an inactivating mutations in the PCSK9 gene have higher plasma LDL levels than wild-type individuals

a. on average, individuals with an inactivating mutation in the PCSK9 gene have lower plasma LDL levels than wild-type individuals

From the superior vena cava, blood flows to the ______________ a. right atrium b. left atrium c. aorta d. capillaries of the lungs e. inferior vena cava

a. right atrium

In this statement supported or not supported by the graph? To train as a middle-distance runner, an average person should increase the percentage of slow fibers at the expense of fast fibers a. supported b. not supported c. cannot be determined from the graph

a. supported

What result would you expect if you transplanted the SCN of τ hamsters into no-rhythmic-activity mutants? a. the recipients would have rhythmic activity with a period of about 20 hours b. the recipients would have rhythmic activity with a period of about 24 hours c. the recipients would have no rhythmic activity d. the recipients would have rhythmic activity with a variety of periods ranging from 20 to 24 hours

a. the recipients would have rhythmic activity with a period of about 20 hours

The peripheral nervous system (PNS) transmits information to and from the central nervous system (CNS) and plays a role in regulating an animal's movements and internal environment. Determine which of the following statements about the PNS are true. Select the four statements that are true. a. the sympathetic division of the PNS prepares the body for physical exertion in stressful situations b. neurons in the parasympathetic division release neurotransmitters that act on receptors that slow heart rate c. the autonomic nervous system controls the action of skeletal muscle d. the sympathetic and parasympathetic divisions consist of afferent neurons e. the sympathetic division amplifies the effect of the parasympathetic division f. parasympathetic nerves are associated with the cranial and sacral regions of the spinal cord, whereas sympathetic nerves associated with the thoracic and lumbar regions g. stimulating the org

a. the sympathetic division of the PNS prepares the body for physical exertion in stressful situations b. neurons in the parasympathetic division release neurotransmitters that act on receptors that slow heart rate f. parasympathetic nerves are associated with the cranial and sacral regions of the spinal cord, whereas sympathetic nerves associated with the thoracic and lumbar regions g. stimulating the organs of digestion is a parasympathetic response

Comparing these two histograms allowed researchers to draw a conclusion regarding the effect of PCSK9 mutations on LDL cholesterol levels in blood. Now consider two individuals with a plasma LDL level of 160 mg/dL, one from the study group and one from the control group. What do you predict regarding their relative risk for cardiovascular disease? a. their risk is equal because their LDL levels are the same b. the risk of individual from the study group is lower because individuals with an inactivating mutation in one copy of the PCSK9 gene had a lower average LDL level than wild-type individuals c. the risk of the wild-type individual is lower because wild-type individuals had a lower average LDL level than individuals with an inactivating mutation in one copy of the PCSK9 gene d. it is impossible to tell because the histograms overlap so much

a. their risk is equal because their LDL levels are the same

Why did the researchers use more than one hamster for each procedure? a. to assess whether the differences in cycle period before and after transplant were greater than variation in cycle period from animal to animal b. to assess whether the SCN or some other part of the hypothalamus is responsible for circadian rhythm c. to assess the variability of circadian rhythms across different individuals d. to determine whether the results were consistent regardless of the sex of the animals

a. to assess whether the differences in cycle period before and after transplant were greater than variation in cycle period from animal to animal

What is the advantage of using log scales for plotting data with a wide range of values? a. you can use axes that are a reasonable length b. you can compare animals with different forms of locomotion (flying, running, swimming) c. you can draw best-fit liens for the data d. you can use axes that are very long

a. you can use axes that are a reasonable length

What can you conclude about the role of the SCN in determining the period of the circadian rhythm? a. the SCN determines the period of the circadian rhythm in the wild-type hamster but not τ hamsters b. the SCN determines the period of the circadian rhythm c. the SCN does not determine the period of the circadian rhythm d. the SCN determines the period of the circadian rhythm in τ hamsters but not wild-type hamsters

b. the SCN determines the period of the circadian rhythm

What do the orange bars on the graph represent? a. the number of slow muscle fibers in individuals with different athletic abilities b. the percentage of slow muscle fibers in individuals with different athletic abilities c. the percentage of people who fall into each category of athletic ability d. the athletic ability of an individual

b. the percentage of slow muscle fibers in individuals with different athletic abilities

In the diagram, (a), (b), and (c) represent three points along a vertebrate axon where electrodes were implanted to detect action potentials. Under normal conditions, when this neuron produces an action potential, the action potential passes through point (a) first, followed by point (b), and then point (c). Suppose, however, that an action potential is artificially triggered at the point indicated by the red arrow. In what sequence would the action potential pass through points (a), (b), and (c)? Enter the sequence in which the action potential would pass through the points. Enter the letters in the correct order separated by commas. For example if the order is point (c), then (b), then (a), enter c, b, a. If the action potential would not pass though a point, do not include that point in your answer.

b,a,c Under the artificial conditions, the axon membrane is initially at resting potential everywhere except at the location indicated by the red arrow (where the membrane is artificially brought to threshold). Voltage-gated Na+ channels at that location open and Na+ ions rush into the cell. The depolarization caused by this influx of Na+ ions is "felt" both to the right and left of the open channels. Voltage-gated Na+ channels on both sides open, resulting in an action potential that moves in both directions. It reaches nearby locations (on both sides) first, then locations farther away.

The slopes of the flying and swimming lines are very similar. Based on your answer to Part C, if the energy cost of a 2-g swimming animal is 1.2 cal/kg•m, what is the estimated energy cost of a 2-kg swimming animal? a. 0.012 cal/kg•m b. 0.12 cal/kg•m c. 1.2 cal/kg•m d. 12 cal/kg•m

b. 0.12 cal/kg•m

Based on the graph, how much greater is the energy cost of flying for an animal that weighs 10-3 g than for an animal that weighs 1 g? a. 2 times greater b. 10 times greater c. 90 times greater d. 100 times greater

b. 10 times greater

Compare the concentrations for methadone (2 ×× 10-8 M) and phenobarbital (10-4 M). Which concentration is higher and by how much? a. Phenobarbital's concentration is 500 times higher. b. Phenobarbital's concentration is 5,000 times higher. c. Phenobarbital's concentration is 2,000 times higher. d. Methadone's concentration 20,000 times higher.

b. Phenobarbital's concentration is 5,000 times higher.

When the researchers repeated the experiment using tissue from mammalian intestinal muscles rather than brains, they found no naloxone binding. What does this result suggest about opiate receptors in mammalian intestinal muscle tissue? a. There may be opiate receptors in mammalian intestinal muscle tissue. Further experiments are needed to be sure. b. There are no opiate receptors in mammalian intestinal muscle tissue. c. There are opiate receptors in mammalian intestinal muscle tissue. d. There are no naloxone receptors in mammalian intestinal muscle tissue, but there are opiate receptors.

b. There are no opiate receptors in mammalian intestinal muscle tissue.

In 20% of the hamsters, there was no restoration of rhythmic activity following the SCN transplant. Can you be confident of your conclusion about the role of the SCN based on data from 80% of the hamsters? Why or why not? a. No. The most likely explanation is that the SCN does not control the circadian rhythm in hamsters b. Yes. The data from 80% of the hamsters are very consistent. In the other 20%, the transplanted SCN may not have established functional connections with the recipient's brain c. Yes. Because 80% is much higher than 20%, the result is reliable d. No. A failure rate of 20% is much too high in any experiment

b. Yes. The data from 80% of the hamsters are very consistent. In the other 20%, the transplanted SCN may not have established functional connections with the recipient's brain

What percentage of individuals in the control group had an LDL level below 100 mg/dL? a. about 5% b. about 17% c. about 40 % d. about 58%

b. about 17%

Which letter indicates diastolic pressure? a. a b. b c. c d. i

b. b

Which letter indicates the arteries? a. c b. d c. e d. f

b. d

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? a. d b. e c. g d. h

b. e

Which letter indicates the vessels in which blood travels the most slowly? a. e b. f c. g d. h

b. f

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 a. true b. false

b. false

Which letter indicates the venules? a. f b. g c. h d. i

b. g

From the pulmonary veins, blood flows to the ___________________ a. right atrium b. left atrium c. aorta d. capillaries of the lungs e. inferior vena cava

b. left atrium

Suppose researchers identified a mutation that caused hamsters to have no rhythmic activity. Also suppose you transplanted the SCN of wild-type hamsters into hamsters with this mutation. What result would you expect from this experiment, assuming that the SCN determines the period of the circadian rhythm? a. the recipients would have rhythmic activity with a period of about 20 hours b. the recipients would have rhythmic activity with a period of about 24 hours c. the recipients would have no rhythmic activity d. the recipients would have rhythmic activity with a variety of periods ranging from 20 to 24 hours

b. the recipients would have rhythmic activity with a period of about 24 hours

For the wild-type hamsters that received τ SCN transplants, what would have been an appropriate control? a. transplant the SCN from one τ hamster to another τ hamster b. transplant the SCN from one wild-type hamster to another wild-type hamster c. surgically expose the brain of a τ hamster without removing the SCN d. transplant the entire hypothalamus from a τ hamster to a wild-type hamster

b. transplant the SCN from one wild-type hamster to another wild-type hamster

Which of the following statements about blood circulation in the body is true? a. during one cardiac cycle, the two ventricles contract first, and then the two atria contract b. valves prevent the backflow of blood into the atria and ventricles c. as the right ventricle contracts, it send oxygenated blood through the aorta to all tissues of the body d. deoxygenated blood flowing through the pulmonary veins is carried to the right atrium

b. valves prevent the backflow of blood into the atria and ventricles

The body masses of the animals used in these experiments ranged from about 0.001 g to 1,000,000 g, and their rates of energy use ranged from about 0.1 cal/kg•m to 100 cal/kg•m. If you were to plot these data on a graph with linear instead of log scales for the axes, how would you draw the axes so that all of the data would be visible? a. you would have to use a scale with large intervals for each axis and make both axes very short b. you would have to use a scale with small intervals for each axis and make both axes very long c. you would have to use a scale with small intervals for each axis and make both axes very short d. you must have to use a scale with large intervals for each axis and make both axes very long

b. you would have to use a scale with small intervals for each axis and make both axes very long

In a relaxed muscle, the myosin heads of the sarcomeres' thick filaments are extended and ready to bind to the actin strands of the thin filaments. But this binding does not occur until an action potential is triggered in the muscle cell. An action potential results in the release of Ca2+ ions from the sarcoplasmic reticulum into the cytosol of the muscle cell. As the concentration of Ca2+ rises in the cytosol, so does the concentration of Ca2+ in the sarcomeres. In response to changes in the Ca2+ concentration in the sarcomeres, two protein components of the thin filaments, troponin and tropomyosin, control access to actin's myosin-binding sites. In this way, Ca2+ concentration in the cytosol and sarcomeres regulates muscle contraction. Which of the following statements correctly describe(s) the relationship between Ca2+ concentration in the cytosol and the response in the sarcomere? Select all that apply. a. In

c. Decreasing Ca2+ concentration causes dissociation of Ca2+ from troponin. d. Increasing Ca2+ concentration causes movement of tropomyosin, exposing myosin-binding sites on actin.

Propagation of an action potential in a skeletal muscle cell links the signal from a motor neuron to contraction of the muscle cell. An action potential in a muscle cell is propagated by the same mechanism as in neurons, the sequential opening and closing of voltage-gated Na+ and K+ channels in the plasma membrane. However, in muscle cells, the topography of the plasma membrane is quite different than in neurons, and this difference is critical to the function of muscle cells.Which of the following statements correctly describe(s) T tubules and their role in conducting action potentials in muscle cells? Select all that apply. a. T tubules lack the voltage-gated Na+ and K+ channels that are present in the plasma membrane b. T tubules are extensions of the sarcoplasmic reticulum that are in contact with the plasma membrane c. T tubules carry action potentials into the interior of the muscle cell via voltage-gated Na+

c. T tubules carry action potentials into the interior of the muscle cell via voltage-gated Na+ and K+ channels d. Without T tubules, the muscle cell would not be able to contract e. T tubules are infoldings of the plasma membrane that encircle the myofibrils and are in contact with the sarcoplasmic reticulum

Morphine, methadone, and levorphanol blocked naloxone binding in this experiment. What do these results indicate about the brain receptors for naloxone? a. They are specific for the non-opiate drugs used in the experiment. b. They are specific for morphine. c. They are specific for opiate drugs. d. They are specific for both opiate and non-opiate drugs.

c. They are specific for opiate drugs.

The percentage of intermediate muscle fibers plus fast muscle fibers in world-class sprinters is approximately the same as the percentage of slow muscle fibers in _____________________________ a. a middle-distance runner b. an extreme endurance athlete c. a world-class marathon runner d. an average active person

c. a world-class marathon runner

The results are presented using a form of bar graph called a histogram. In a histogram, the variable on the x-axis is grouped into ranges. The height of each bar in this histogram represents the percentage of samples that fall into the range specified on the x-axis for that bar. For example, in the top histogram, about 4% of individuals studied had plasma LDL cholesterol levels in the 25-50 mg/dL (milligrams per deciliter) range. What percentage of individuals in the study group had an LDL level below 100 mg/dL? (Hint: Add the percentages for the relevant bars.) a. about 17% b. about 35% c. about 58% d. about 79%

c. about 58%

What traits of individual hamsters would likely have been controlled across the treatment groups? a. age only b. genotype c. age and sex d. sex only

c. age and sex

Is this statement supported or not supported by the graph? World-class sprinters are born with a higher percentage of fast and intermediate muscle fibers than only other people have a. supported b. not supported c. cannot be determined from the graph

c. cannot be determined from the graph

What general trends does the graph reveal about the period of circadian rhythm in transplant recipients? a. it was similar to that of the donor in τ hamsters but similar to that of the recipient in wild-type hamsters b. it was determined by the genotype of the recipient c. it was similar to that of the donor, whether the recipient was wild-type or τ mutant d. it was similar to that of the donor in wild-type hamsters but similar to that of the recipient in τ hamsters

c. it was similar to that of the donor, whether the recipient was wild-type or τ mutant

Blood returns to the heart via the ________________ a. aorta b. pulmonary arteries c. pulmonary veins d. aorta and pulmonary arteries e. aorta and pulmonary veins

c. pulmonary veins

Considering animals with a body mass of about 100 g, rank the three forms of locomotion from highest energy cost to lowest energy cost. a. swimming, flying, running b. flying, running, swimming c. running, flying, swimming d. running, swimming, flying

c. running, flying, swimming

Schmidt-Nielson calculated the swimming cost for a mallard duck and found that it was nearly 20 times the swimming cost for a salmon of the same body mass. What could explain the greater swimming efficiency of salmon? a. larger animals travel more efficiently than smaller animals b. the mallard duck has to overcome more gravity than the salmon c. salmon have a streamlined body and are generally better adapted for swimming d. salmon have more efficient muscles

c. salmon have a streamlined body and are generally better adapted for swimming

According to the graph, which type of muscle fiber predominates in endurance athletes (marathon runners and extreme endurance athletes)? a. intermediate b. a commendation of intermediate and fast muscle fibers c. slow d. fast

c. slow

In a controlled experiment, researchers manipulate one variable at a time. What was the experimental variable in this study? a. the genotype of the host tissue b. whether the hamster's original SCN was removed c. the genotype of the transplanted tissue d. whether the SCN was part of the transplanted tissue

c. the genotype of the transplanted tissue

Why do the circulatory systems of land vertebrates have separate circuits to the lungs and to the rest of the body? a. blood is pumped to the lungs to be oxygenated before being pumped to the rest of the body b. land vertebrates are bigger and require more tubbing to reach all areas of the body c. the large decrease in blood pressure as blood moves through the lungs may prevent efficient circulation through the rest of the body d. the circuits increase the amount of surface area available for the diffusion of gases and nutrients in the body

c. the large decrease in blood pressure as blood moves through the lungs may prevent efficient circulation through the rest of the body

How would you predict the risk for cardiovascular disease to compare between the study group and the control group? a. it is impossible to tell from the data b. the study group has the same risk as the control group c. the study group has a lower risk than the control group d. the study group has a higher risk than the control group

c. the study group has a lower risk than the control group

For any given form of locomotion, does a larger animal or a smaller animal travel more efficiently? a. a larger animal travels more efficiently for running and swimming, but a smaller animal travels more efficiently for flying b. a smaller animal travels more efficiently for all forms of locomotion c. a larger animals travels more efficiently for running, but a smaller animal travels more efficiently for flying and swimming d. a larger animal travels more efficiently for all forms of locomotion

d. a larger animal travels more efficiently for all forms of locomotion

Which letter indicates the vessels in which blood velocity is increasing the most due to a decrease in the total combined cross-sectional area of those vessels? a. d b. e c. g d. h

d. h

The strength of a stimulus (for example, whether you feel a slight pain versus an intense pain) determines the number of action potentials sent along an axon. As the graphs show, a strong stimulus produces more action potentials spaced more closely together than a weak stimulus. The time between when a first action potential ends and a second action potential can be triggered is determined by the axon's refractory period. A second action potential cannot be triggered until the end of the refractory period. a. how long it takes for the membrane potential to return to resting potential after the undershoot phase b. how long it takes for the voltage-gated K+ channels to close during the undershoot phase c. how long it takes for the voltage-gated Na+ channels to close at the end of an action potential d. how long it takes for the voltage-gated Na+ channels to reactivate at the end of an action potential e. how low the

d. how long it takes for the voltage-gated Na+ channels to reactivate at the end of an action potential

Which letter indicates the vessels in which blood pressure is the lowest? a. f b. g c. h d. i

d. i

Which statement about human blood vessels is correct? a. arteries carry oxygenated blood; veins carry oxygen-poor blood b. arteries carry blood toward the atria of the heart c. the pulmonary artery carries oxygen-rich blood from the lungs d. pulmonary veins carry oxygen-rich blood the heart e. veins transport blood from the heart to the capillaries

d. pulmonary veins carry oxygen-rich blood the heart

Which event occurs first during atrial and ventricular diastole? a. the atria contract while blood flows into the relaxed ventricles b. blood flows into the relaxed atria while the ventricles contract c. the atria and ventricles contract simultaneously d. the atria and ventricles are relaxed, and blood flows into the atria

d. the atria and ventricles are relaxed, and blood flows into the atria

Which event of the cardiac cycle occurs when systolic blood pressure is measured? a. the atria and ventricles contract simultaneously b. the atria and ventricles are relaxed, and blood flows into the atria c. the atria contract while blood flows into the relaxed ventricles d. the ventricles contract, carrying blood into the aorta, and blood flows into the relaxed atria

d. the ventricles contract, carrying blood into the aorta, and blood flows into the relaxed atria

In which of the following animals are circulatory fluid and interstitial fluid considered to be the same body fluid? a. sparrows b. jellyfish c. dogs d. fishes e. grasshoppers

e. grasshoppers

From the capillaries of the abdominal organs and hind limbs, blood flows to the _______________________ a. right atrium b. left atrium c. aorta d. capillaries of the lungs e. inferior vena cava

e. inferior vena cava