Test Prep for AP® Courses

31.

The cell of the unicellular algae Ventricaria ventricosa, shown in the photo, is one of the largest known, reaching 1 to 5 cm in diameter. Like all single-celled organisms, V. ventricosa exchanges gases across the cell membrane.

The photo shows a round, green cell with a smooth, shiny surface. The cell resembles a balloon.

What adaptations would V. ventricosa likely have evolved related to its large size and ability to exchange materials with the outside environment?

  1. adaptations that would decrease cell metabolism to meet the needs of the large cell
  2. adaptations that would make the cell thicker, to reduce the loss of nutrients
  3. adaptations that make diffusion or nutrient passage across their cell membrane more efficient due to the large size of the cell
  4. adaptations that allow the cell to take in larger food objects using the components of its cell membrane
32.

In the past, Earth has experienced environmental changes, which have changed the amount of available oxygen and carbon dioxide in the water and air. For example, there is evidence of less oxygen available in the air during the time of the dinosaurs, a result of high volcanic activity creating a large amount of carbon dioxide. How might red blood cells in the dinosaurs have evolved, in terms of size and shape, to adapt to the lower-oxygen atmosphere?

  1. evolve smaller size and flatter shape
  2. evolve larger size and a pointy shape
  3. evolve smaller size and a thicker shape
  4. evolve larger size and a shorter shape
33.

The diagram shows a human alveolus, which is part of the respiratory system.

The illustration shows a terminal bronchial tube branching into three alveolar ducts. At the end of each duct is an alveolar sac made up of 20 to 30 alveoli clustered together, like grapes. Arrow A in the terminal bronchial tube shows the flow of air away from the alveoli. Arrow B shows the flow of blood toward the capillaries of the alveoli.

What do arrows A and B represent in the diagram above?

  1. A: inhaled air; B: blood travelling from the heart
  2. A: exhaled air; B: blood travelling from the heart
  3. A: inhaled air; B: blood travelling to the heart
  4. A: exhaled air; B: blood traveling from the heart
35.

Intubation is a procedure used by ambulance crews that allows a person to breathe if part of the respiratory system is blocked by a foreign object (or otherwise injured). During intubation, a long, plastic tube is placed in the respiratory system so that air can bypass the obstructed area and reach the lungs. Typically, air is supplied artificially using a squeezable bag that connects to the top of the tube.The illustration shows the human respiratory system. The nasal cavity is a wide cavity above and behind the nostrils, and the pharynx is the passageway behind the mouth. The nasal cavity and pharynx join and enter the trachea through the larynx. The larynx is somewhat wider than the trachea and flat. The trachea has concentric, ring-like grooves, giving it a bumpy appearance. The trachea bifurcates into two primary bronchi, which are also grooved. The primary bronchi enter the lungs, and branch into secondary bronchi. The secondary bronchi in turn branch into many tertiary bronchi. The tertiary bronchi branch into bronchioles, which branch into terminal bronchioles. The diaphragm pushes up against the lungs. There is an intubation site indicated at the beginning of the pharynx. A patient has been surgically intubated in the location shown in the diagram.

The illustration shows the respiratory system. The airways in the mouth and nose connect to a wide, cartilaginous structure, which in turn opens into a long, cartilaginous tube. At the bottom, this tube branches into each lung. The intubation side is beneath the airways of the mouth and nose but above the wide, cartilaginous structure.

Based on this information, where did the injury likely occur in the patient’s respiratory system? Justify your answer.

  1. in the oral cavity, because it is above the injury
  2. in the oral cavity, because it is below the injury
  3. in the larynx, because it is above the injury
  4. in the larynx, because it is below the injury
35.

An organism’s body systems work to maintain homeostasis by adjusting when body cells need more oxygen or are experiencing a buildup of carbon dioxide. How would the body most likely react to the  difference between the blood vessel and body cell, as shown in the diagram?

This figure shows that the partial pressure of oxygen in a blood vessel and a body cell is the same, 46 millimeters of mercury.

Figure 30.24
  1. generating neural signals that stimulate the heart to beat at a slower rate
  2. releasing hormones that stimulate body cells to undergo more active transport
  3. releasing red blood cells that can accept oxygen using diffusion as opposed to facilitated passive transport
  4. adjust blood pH to decrease the partial pressure of CO2 in the body cells
36.

The diagram shows a red blood cell in a capillary and a cell in a body tissue.

This figure shows a red blood cell in a capillary and a nearby body cell. Double arrows indicate that oxygen and carbon dioxide flow between the red blood cell and the body cell, but do not indicate the direction of flow.

Figure 30.25

In which direction should the arrows point for the diffusion of oxygen and CO2? How should each partial pressure (body cell and RBC) be labeled as high or low to accomplish this diffusion?

  1. O2→ CO2←; Body cell PO2 = low; RBC PO2 = high; Body cell PCO2 = high, RBC PCO2 = low
  2. O2← CO2→; Body cell PO2 = high; RBC PO2 = low; Body cell PCO2 = low, RBC PCO2 = high
  3. O2← CO2→; Body cell PO2 = low; RBC PO2 = high; Body cell PCO2 = high, RBC PCO2 = low
  4. O2→ CO2←; Body cell PO2 = high; RBC PO2 = low; Body cell PCO2 = low, RBC PCO2 = high
37.

The graph plots percent oxygen saturation of hemoglobin as a function of oxygen partial pressure in the alveoli. Oxygen saturation increases in an S-shaped curve, from 0–100 percent as the partial pressure of oxygen increases from 0 to 100.

The graph shows how the percent oxygen saturation of hemoglobin changes with the partial pressure of oxygen in alveoli. When the partial pressure of oxygen is zero, no oxygen is bound to hemoglobin. The partial pressure increases gradually as partial pressure increases to 15 millimeters of mercury, then rises rapidly. At about 60 millimeters of mercury the rise in oxygen saturation slowly tapers off. At 100 millimeters of mercury, oxygen saturation of hemoglobin is about 95 percent.

Figure 30.26

What happens as the curve levels off around a partial pressure of 60 mmHg?

  1. As the percent saturation of hemoglobin increases to its maximum, hemoglobin’s affinity for oxygen increases as the availability of oxygen increases.
  2. As the percent saturation of hemoglobin decreases (without all of the oxygen dissociating), hemoglobin’s affinity for oxygen decreases as the availability of oxygen decreases.
  3. As the percent saturation of hemoglobin increases to very high levels, hemoglobin’s affinity for oxygen decreases due to its decreasing ability to bind oxygen.
  4. As the percent saturation of hemoglobin decreases, hemoglobin’s affinity for oxygen increases as the availability of oxygen decreases.
38.

The graph shows an oxygen dissociation curve for hemoglobin.

The graph shows how the percent oxygen saturation of hemoglobin changes with the partial pressure of oxygen in alveoli. A solid line indicates that oxygen saturation initially rises slowly, then rises rapidly, then tapers off. A dotted line follows the same trend as the solid line but is shifted slightly to the left.

Based on the graph, what would likely cause the curve to shift to the left, as shown by the dotted plot line?

  1. Decreasing carbon dioxide, increasing pH, or decreasing temperature
  2. Increasing carbon dioxide, decreasing pH, or decreasing temperature
  3. Decreasing carbon dioxide, decreasing pH, or decreasing temperature
  4. Increasing carbon dioxide, increasing pH, or increasing temperature
39.

The graph shows an oxygen dissociation curve for hemoglobin.

The graph shows an oxygen dissociation curve for hemoglobin. The percentage of oxygen saturation of hemoglobin on the y axis from zero to 100 percent over the partial pressure of oxygen in the alveoli from zero to 100. A solid line indicates that oxygen saturation initially rises slowly, then rises rapidly, then tapers off. A dotted line follows the same trend as the solid line but is shifted slightly to the right.

Based on the graph, what would likely cause the curve to shift to the right, as shown by the dotted plot line?

  1. decreasing carbon dioxide, increasing pH, or decreasing temperature
  2. decreasing carbon dioxide, decreasing pH, or decreasing temperature
  3. increasing carbon dioxide, increasing pH or increasing temperature.
  4. increasing carbon dioxide, decreasing pH, or increasing temperature.