Question 1

A researcher is studying a strain of mice that only incorporates 50% of the necessary iron into its hemoglobin molecules. Which of the following statements is likely TRUE regarding these mutant mice?

Accepted Answer

Hemoglobin molecules require all four subunits to be fully functional, with each subunit containing an iron-containing heme group. If only 50% of the necessary iron is incorporated into the heme groups, then only half of the subunits will be functioning properly, leading to a decreased ability to bind oxygen. Therefore, 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.

Question 2

Aneurysms are the result of which of the following?

Accepted Answer

Aneurysms are primarily caused by the deterioration of elastin and collagen in arteries (A) and by pressure pulses in arteries (C). The weakening of the arterial wall due to the loss of structural proteins like elastin and collagen can lead to aneurysms, as can the constant pressure fluctuations experienced by arteries. Veins are less commonly associated with aneurysms due to their lower pressure and different structure compared to arteries.

Question 3

Which of the following types of blood vessels would have the greatest resistance to flow?

Accepted Answer

Capillaries have the greatest resistance to flow because they are the smallest and most numerous blood vessels.

Question 4

In the figure below, the cell is _____ to the solution. If the membrane is permeable to water, but not to solutes, net movement of water will be _____ the cell.

Accepted Answer

The answer of In the figure below, the cell is...

Question 5

Which of the following statements are TRUE regarding lymph and the lymphatic system?

Accepted Answer

A) This statement is false. Lymph contains some proteins, but they are not necessarily rich.
B) This statement is true. Lymph contains water that has been filtered out of the bloodstream.
C) This statement is false. The lymphatic system has its own set of vessels that are separate from the circulatory system.
D) This statement is true. The lymphatic system is composed of its own distinct set of vessels, through which blood does not travel.

Question 6

The pit viper Bothrops jararaca makes a venom that was used as an arrowhead poison by indigenous tribes of Brazil. This venom inhibits the enzyme necessary to activate angiotensin. Angiotensin is a naturally occurring peptide hormone that causes vasoconstriction and thirst. Why would a molecule that inhibits the activation of a natural vasoconstrictor be poisonous?

Accepted Answer

Inhibiting the activation of angiotensin would cause a decrease in blood pressure since angiotensin causes vasoconstriction, thus narrowing blood vessels and increasing blood pressure. A drop in blood pressure can be fatal as it may result in inadequate oxygen supply to vital organs.

Question 7

Much of the fluid that moves across capillary walls and into the tissues moves as a result of filtration, forced by blood pressure. O₂, on the other hand, travels from the capillaries into the tissues because:

Accepted Answer

O₂, which is a placeholder for a specific substance (not specified in the question), moves from the capillaries into the tissues due to a concentration gradient between the substance in the tissues and in the blood. This implies that the movement is from an area of higher concentration to an area of lower concentration, a fundamental principle of diffusion.

Question 8

Which of the following statements explains why there is an elastic layer found in arteries, but not veins?

Accepted Answer

Blood pressure is higher in arteries than veins, and the elastic layer helps maintain the structure of the artery. Veins, on the other hand, rely on valves to prevent backflow of blood and do not need an elastic layer to maintain their structure.

Question 9

Unlike open circulatory systems, closed circulatory systems are more efficient at delivering oxygenated blood directly to tissues according to their metabolic and energetic demands.

Accepted Answer

Closed circulatory systems, found in vertebrates and some invertebrates, have a higher degree of control over blood flow and can direct oxygenated blood precisely where it is needed, making them more efficient than open circulatory systems where blood is not confined to vessels and the degree of control is limited.

Question 10

In the open circulatory system of insects, blood is returned to the ventral tubular hearts through:

Accepted Answer

In insects with an open circulatory system, blood (or hemolymph) is returned to the heart through a mechanism involving suction created by the movement of hemolymph from the posterior part of the body towards the anterior part. This movement is facilitated by the body's natural movements and the structure of the circulatory system, rather than through vessels specifically designed for feeding back into the heart or the direct action of body or locomotion muscles.

Question 11

A lioness begins her nightly hunt after spending the day beneath a tree in the Serengeti. What happens to the blood vessels in her body as she goes from resting to hunting?

Accepted Answer

When the lioness transitions from resting to hunting, her body prioritizes blood flow to essential muscles for the hunt. This means arterioles supplying her stomach and intestines constrict to divert blood to her muscles, where arterioles expand to increase oxygen and nutrient delivery for increased activity.

Question 12

If a hemoglobin molecule comes into close contact with a respiring cell, the presence of CO₂ in the environment will cause hemoglobin to bind to more oxygen molecules (if it is not already bound to four).

Accepted Answer

Hemoglobin's affinity for oxygen is decreased in the presence of CO2, increased H+ concentration (lower pH), increased temperature, and 2,3-BPG, which are conditions typically found in respiring tissues, leading to the release of oxygen to those tissues.

Question 13

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?

Accepted Answer

Mountain goats live at higher altitudes where there is less oxygen available. To compensate for this, their hemoglobin will have a greater oxygen-binding affinity, allowing them to transport oxygen more efficiently. Conversely, barnyard goats living at lower altitudes have a lower demand for oxygen and therefore their hemoglobin does not need to have as high of an oxygen-binding affinity.

Question 14

As fluid moves through a vessel, which factors determine the flow resistance?

Accepted Answer

The flow resistance of a vessel is determined by the viscosity of the fluid (A), the length of the vessel (B), and the radius of the vessel (C). The pressure exerted by the heart (D) may affect overall blood flow in the body, but it does not determine flow resistance in an individual vessel.

Question 15

Baroreceptors are pressure receptors found in the major arteries. If these receptors detect a fall in blood pressure, signals go to the:

Accepted Answer

Baroreceptors detect a fall in blood pressure and send signals to the sympathetic neurons that synapse on smooth muscles surrounding the arterioles of the limbs. This stimulation causes the arterioles to constrict, increasing the resistance in the vessels and increasing blood pressure. Parasympathetic neurons do not have a significant role in regulating arterial blood pressure.

Question 16

Imagine that during her hunt, the same lioness wounds a gazelle. The gazelle is able to escape, but its blood pressure is rapidly decreasing as it loses blood. What can happen in the gazelle's body to increase blood pressure?

Accepted Answer

Vasopressin increases water reabsorption in kidneys, raising blood volume and pressure. The sympathetic nervous system can cause arterioles to constrict, increasing blood pressure.

Question 17

Which of the following would NOT be considered a component of a hemoglobin molecule?

Accepted Answer

The answer of Which of the following would NOT be...

Question 18

The muscles of which of the following organisms would likely have the lowest myoglobin concentration?

Accepted Answer

Myoglobin is a protein found in muscle cells that binds oxygen, allowing for more efficient oxygen use during muscle activity. Aquatic mammals like whales, dolphins, and seals, which dive deep and hold their breath for extended periods, have evolved to have higher myoglobin concentrations to support their oxygen needs underwater. Humans, being primarily terrestrial and not adapted for prolonged underwater activity, would likely have the lowest myoglobin concentration among the options listed.

Question 19

The illustration below diagrams osmotic (red arrows) and blood pressures (green arrows) as a function of distance along a capillary. This illustration explains why:

Accepted Answer

The answer of The illustration below diagrams osmotic (red arrows)...

Question 20

A researcher has introduced molecules of human myoglobin and hemoglobin into a solution containing oxygen. Which of the following statements is TRUE of human hemoglobin and myoglobin?

Accepted Answer

Myoglobin binds oxygen more quickly and with higher affinity than hemoglobin, but it binds only one oxygen molecule, whereas hemoglobin can bind up to four.

Quiz 39: Animal Cardiovascular and Respiratory Systems

A researcher is studying a strain of mice that only incorporates 50% of the necessary iron into its hemoglobin molecules. Which of the following statements is likely TRUE regarding these mutant mice?

Aneurysms are the result of which of the following?

Which of the following types of blood vessels would have the greatest resistance to flow?

In the figure below, the cell is _ to the solution. If the membrane is permeable to water, but not to solutes, net movement of water will be _ the cell.

Which of the following statements are TRUE regarding lymph and the lymphatic system?

Much of the fluid that moves across capillary walls and into the tissues moves as a result of filtration, forced by blood pressure. O₂, on the other hand, travels from the capillaries into the tissues because:

Which of the following statements explains why there is an elastic layer found in arteries, but not veins?

Unlike open circulatory systems, closed circulatory systems are more efficient at delivering oxygenated blood directly to tissues according to their metabolic and energetic demands.

In the open circulatory system of insects, blood is returned to the ventral tubular hearts through:

A lioness begins her nightly hunt after spending the day beneath a tree in the Serengeti. What happens to the blood vessels in her body as she goes from resting to hunting?

If a hemoglobin molecule comes into close contact with a respiring cell, the presence of CO₂ in the environment will cause hemoglobin to bind to more oxygen molecules (if it is not already bound to four).

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?

As fluid moves through a vessel, which factors determine the flow resistance?

Baroreceptors are pressure receptors found in the major arteries. If these receptors detect a fall in blood pressure, signals go to the:

Imagine that during her hunt, the same lioness wounds a gazelle. The gazelle is able to escape, but its blood pressure is rapidly decreasing as it loses blood. What can happen in the gazelle's body to increase blood pressure?

Which of the following would NOT be considered a component of a hemoglobin molecule?

The muscles of which of the following organisms would likely have the lowest myoglobin concentration?

The illustration below diagrams osmotic (red arrows) and blood pressures (green arrows) as a function of distance along a capillary. This illustration explains why:

A researcher has introduced molecules of human myoglobin and hemoglobin into a solution containing oxygen. Which of the following statements is TRUE of human hemoglobin and myoglobin?

Quiz 39: Animal Cardiovascular and Respiratory Systems

A researcher is studying a strain of mice that only incorporates 50% of the necessary iron into its hemoglobin molecules. Which of the following statements is likely TRUE regarding these mutant mice?

Aneurysms are the result of which of the following?

Which of the following types of blood vessels would have the greatest resistance to flow?

In the figure below, the cell is _____ to the solution. If the membrane is permeable to water, but not to solutes, net movement of water will be _____ the cell.

Which of the following statements are TRUE regarding lymph and the lymphatic system?

Much of the fluid that moves across capillary walls and into the tissues moves as a result of filtration, forced by blood pressure. O2, on the other hand, travels from the capillaries into the tissues because:

Which of the following statements explains why there is an elastic layer found in arteries, but not veins?

Unlike open circulatory systems, closed circulatory systems are more efficient at delivering oxygenated blood directly to tissues according to their metabolic and energetic demands.

In the open circulatory system of insects, blood is returned to the ventral tubular hearts through:

A lioness begins her nightly hunt after spending the day beneath a tree in the Serengeti. What happens to the blood vessels in her body as she goes from resting to hunting?

If a hemoglobin molecule comes into close contact with a respiring cell, the presence of CO2 in the environment will cause hemoglobin to bind to more oxygen molecules (if it is not already bound to four).

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?

As fluid moves through a vessel, which factors determine the flow resistance?

Baroreceptors are pressure receptors found in the major arteries. If these receptors detect a fall in blood pressure, signals go to the:

Imagine that during her hunt, the same lioness wounds a gazelle. The gazelle is able to escape, but its blood pressure is rapidly decreasing as it loses blood. What can happen in the gazelle's body to increase blood pressure?

Which of the following would NOT be considered a component of a hemoglobin molecule?

The muscles of which of the following organisms would likely have the lowest myoglobin concentration?

The illustration below diagrams osmotic (red arrows) and blood pressures (green arrows) as a function of distance along a capillary. This illustration explains why:

A researcher has introduced molecules of human myoglobin and hemoglobin into a solution containing oxygen. Which of the following statements is TRUE of human hemoglobin and myoglobin?

In the figure below, the cell is _ to the solution. If the membrane is permeable to water, but not to solutes, net movement of water will be _ the cell.

Much of the fluid that moves across capillary walls and into the tissues moves as a result of filtration, forced by blood pressure. O₂, on the other hand, travels from the capillaries into the tissues because:

If a hemoglobin molecule comes into close contact with a respiring cell, the presence of CO₂ in the environment will cause hemoglobin to bind to more oxygen molecules (if it is not already bound to four).