ls 7c midterm 2

An increase of _____ increases the permeability of the collecting duct to water. caffeine diuretic drug alcohol ADH (antidiuretic hormone)

ADH (antidiuretic hormone)

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

4

Which of the following statements about bird respiration is FALSE? Bird lungs receive fresh air during both inhalation and exhalation. Air flowing through the air channels in the lungs moves in a tidal fashion. The unidirectional flow of air through a bird's lungs maintains a larger concentration gradient for diffusion than can be obtained through tidal breathing. It takes two ventilation cycles for a single breath of air to move through a bird's respiratory system. Oxygen is exchanged between the air and the bloodstream in the lungs, but not in the air sacs.

Air flowing through the air channels in the lungs moves in a tidal fashion.

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

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

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

All of these choices are correct.

Which of the following statements about the control of blood volume and blood pressure is NOT true? Angiotensin II causes the smooth muscle in the walls of the arterioles to contract. A drop in blood pressure stimulates the cells of the juxtaglomerular apparatus to release renin. None of the answer options is false. Inactive angiotensinogen is converted to angiotensin II by an enzyme released from the lungs. Angiotensin II stimulates the release of antidiuretic hormone, which increases salt and water uptake by the distal convoluted tubule.

Angiotensin II stimulates the release of antidiuretic hormone, which increases salt and water uptake by the distal convoluted tubule.

We breathe more quickly and deeply when we exercise. Why does this make sense? (Select all that apply.) Because when we exercise, we hydrolyze more ATP to ADP and Pi, and O2 is necessary for the hydrolysis, so we increase our intake of oxygen. Because when we exercise, we consume more CO2 and must increase ventilation to supply the CO2. Because when we exercise, we use more ATP, and additional O2 is necessary to generate sufficient ATP. Because when we exercise, we produce more CO2 and increased ventilation is necessary to rid ourselves of CO2

Because when we exercise, we produce more CO2 and increased ventilation is necessary to rid ourselves of CO2 Because when we exercise, we use more ATP, and additional O2 is necessary to generate sufficient ATP.

Which of the following occurs during systole? The left ventricle contracts. Both atria contract. The atria fill with blood. Both ventricles contract. The ventricles fill with blood.

Both ventricles contract.

Which of the following statements is FALSE? Larger, more complex animals rely on bulk flow and diffusion to deliver oxygen to their cells, whereas some smaller, simpler animals rely on diffusion alone. 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. Ventilation increases the concentration of oxygen in the air on the outside of the respiratory surface. Oxygen and carbon dioxide both move across the respiratory surface by diffusion.

Circulation requires a pump to generate pressure to drive flow, whereas ventilation does not.

Which of the following statements about the protonephridia of freshwater flatworms is CORRECT? Fluid from the body enters the protonephridia without first being filtered. The fluid passing through the tubules is not modified before excretion. Muscular contractions drive fluid movement through the excretory tubules. The urine leaving the body of a freshwater flatworm is more concentrated than its body fluids. Protonephridia are surrounded by a capillary network to allow for selective reabsorption and secretion.

Fluid from the body enters the protonephridia without first being filtered.

Insects possess _____ circulatory systems, circulatory systems in which hemolymph completely "bathes" the organs and is not typically contained in distinct arteries or veins. fluid solid open closed

open

What is the function of the vasa recta? It helps determine the final concentration of the urine. None of the answer options is correct. It filters the blood within the glomerulus. It maintains the concentration gradient established by the loop of Henle. It secretes the hormone renin in response to a drop in blood pressure.

It maintains the concentration gradient established by the loop of Henle.

Diffusion of materials between the blood and body tissues occurs at which of the following blood vessels? venules veins arteries arterioles capillaries

capillaries

The body fluid of sharks has a much lower concentration of sodium chloride than that of the surrounding seawater, and sharks are able to remain in osmotic equilibrium with the external environment. How can this be the case? Sharks maintain high levels of sodium chloride in their skin. Sharks are osmoregulators. None of the answer options is correct. Sharks drink large volumes of seawater to compensate for the low salt concentration of their body fluids. Sharks store enough urea to match the total solute concentration of the surrounding seawater.

Sharks store enough urea to match the total solute concentration of the surrounding seawater.

If solution X has a 2% concentration of NaCl and solution Y has an 8% concentration of NaCl, which of the following statements is CORRECT? Solution X has a lower concentration of water than solution Y. Solution X is hypertonic relative to solution Y. Solution X has a higher osmotic pressure than solution Y. Solution X is hypotonic relative to solution Y. Solution X has a higher solute concentration than solution Y.

Solution X is hypotonic relative to solution Y.

Fish in a marine environment must maintain a relatively constant ion concentration in their tissues and blood. How do the chloride cells in the gills aid fish in the removal of excess ions? The chloride cells create a countercurrent system where water is lost from the body and chloride ions are absorbed. The chloride cells create a countercurrent system where ions are lost from the body and water is absorbed to dilute other ions (NaCl). The chloride cells actively remove ions from the body and water follows by osmosis. The chloride cells actively move ions into the body and water follows by osmosis.

The chloride cells actively remove ions from the body and water follows by osmosis.

In systemic tissue fluids, the enzyme carbonic anhydrase catalyzes the reaction CO2 + H2O → H2CO3 (which then can dissociate into H+ and HCO3-). In fact, CO2 released from cells is converted to HCO3- ions and travels in that form in the bloodstream. HCO3- is reconverted to CO2 + H2O in the pulmonary capillaries by the same enzyme, and there the CO2 is exhaled. How is it possible for the same enzyme to catalyze reverse reactions? The direction of a reversible reaction is influenced by the concentrations of reactants and products. In pulmonary circulation, the low CO2 concentration favors the formation of CO2 and H2O. There must be two forms of carbonic anhydrase. One form catalyzes the forward reaction CO2 + H2O → H2CO3 and the other catalyzes the reverse reaction H2CO3 → CO2 + H2O. The lungs contain an allosteric inhibitor that prevents the formation of carbonic acid.

The direction of a reversible reaction is influenced by the concentrations of reactants and products. In pulmonary circulation, the low CO2 concentration favors the formation of CO2 and H2O.

Imagine that a young girl suffers a horseback-riding injury, and one of her ribs punctures her diaphragm. How will this injury affect the girl's breathing? The injury will not affect her at all, as intercostal muscles are responsible for breathing. The injury will make it more difficult to decrease negative air pressure in her chest cavity, making inhalation more difficult. The injury will make it easier to increase negative air pressure in her chest cavity, making inhalation easier. The injury will make it more difficult to increase negative air pressure in her chest cavity, making inhalation more difficult.

The injury will make it more difficult to increase negative air pressure in her chest cavity, making inhalation more difficult.

Consider the mammalian heart. Why is the muscular wall of the left ventricle thicker than that of the right ventricle? This difference stems from the fact that frogs have a thicker left ventricular muscle mass. The left ventricle must contract with more force in order to send blood to the body's extremities. The left ventricle has more nerve endings for contraction, and more muscle mass must be there to accommodate the extra neurons. The ventricle wall must be thicker to inhibit diffusion between the right and left ventricle.

The left ventricle must contract with more force in order to send blood to the body's extremities.

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 following statements is CORRECT? There will be a net movement of oxygen from inside the cell to outside the cell. There will be a net movement of oxygen from outside the cell to inside the cell. There will be no net movement of oxygen in either direction. There will be a net movement of carbon dioxide out of the cell. There will be a net movement of carbon dioxide into the cell.

There will be a net movement of oxygen from outside the cell to inside the cell.

Two solutions of water and dissolved potassium and glucose are separated by a selectively permeable membrane that only permits the passage of water. If the two solutions have the same total solute concentration, but solution 1 has a higher concentration of potassium and a lower concentration of glucose than solution 2, which of the following statements is CORRECT? There will be no net movement of water molecules between the solutions. There will be net water movement from solution 1 to solution 2. There will be net glucose movement from solution 2 to solution 1. There will be net water movement from solution 2 to solution 1. There will be net potassium movement from solution 1 to solution 2.

There will be no net movement of water molecules between the solutions.

What function do collagen and elastin have in arteries? They help to control blood flow within the body by contracting with the smooth muscles in the arterial wall. They line the interior to provide a smooth surface for blood flow. All of these choices are correct. They form valves to prevent the backflow of blood. They provide elastic rebound of the arterial wall to help smooth out blood flow.

They provide elastic rebound of the arterial wall to help smooth out blood flow.

What are desirable characteristics for a gas exchange surface, such as the endothelial cells lining the inside of lung? (Select all that apply.) a thickness of 100 micrometers a small surface area a large surface area a thickness under 10 micrometers

a large surface area a thickness under 10 micrometers

Muscle fibers generate maximum force: when the overlap between actin and myosin is minimal. when contracting at short lengths. at intermediate lengths. when the myosin filaments contact the Z discs. when pulled to long lengths before contraction.

at intermediate lengths.

Essential amino acids are those that: can only be found in plants. cannot be synthesized biochemically and must be taken in through the diet. include minerals such as calcium and iron. provide essential vitamins.

cannot be synthesized biochemically and must be taken in through the diet.

A person's blood pressure falls. Which of the following would you expect to occur? (Select all that apply.) circulating concentrations of angiotensin II will decrease circulating concentrations of renin will increase water uptake by the distal convoluted tubule will increase circulating concentrations of aldosterone will decrease

circulating concentrations of renin will increase water uptake by the distal convoluted tubule will increase

Water levels are adjusted to meet the osmoregulatory needs of the organism in the _____ of the nephron under the control of _____, also called vasopressin. collecting ducts; diuretic hormone collecting ducts; antidiuretic hormone loops of Henle; antidiuretic hormone distal convoluted tubule; antidiuretic hormone distal convoluted tubule; diuretic hormone

collecting ducts; antidiuretic hormone

Osmoregulators have _____ internal solute concentrations compared to their external environment. the same always higher always lower different

different

An individual with vitamin D deficiency will experience which of the following problems? anemia slow wound healing bleeding gums and loss of teeth nervous system disorders difficulty absorbing sufficient amounts of calcium from the diet

difficulty absorbing sufficient amounts of calcium from the diet

The _____ is the first section of the small intestine, where food enters from the stomach. gizzard jejunum duodenum ileum

duodenum

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).

false

Imagine that a doctor encounters a patient carrying a mutation that reduces collagen production. As a result, the arteries of this patient will likely be stronger and more resistant to aneurysms compared to arteries in an individual not carrying this mutation. T/F

false

In mammals, bulk flow only refers to the movement of oxygen (either into or out of the lungs and within the bloodstream). Bulk flow never refers to the movement of carbon dioxide. T/F

false

One of the roles of the kidneys is to help buffer body fluids, to keep fluids from becoming too acidic or too basic. The cells of the renal tubule wall secrete H+ into the tubule lumen, and absorb bicarbonate, passing it into the tissue fluid. Consider the reaction catalyzed by the enzyme carbonic anhydrase, shown in the accompanying figure and below.

false

Which of the following processes occur within Bowman's capsule? filtration and selective reabsorption secretion filtration filtration, selective reabsorption, and secretion selective reabsorption

filtration

When skeletal muscles contract such that bone segments move closer together, this action is known as: flexion. tetanus. extension. lengthening contraction

flexion.

During _____ bone segments rotate closer, whereas during _____ bone segments move further apart. contraction; flexion contraction; extension flexion; extension rotation; flexion extension; flexion

flexion; extension

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

frog

Which of the following CORRECTLY describes the path of excretory fluids through a mammalian nephron? collecting duct, proximal convoluted tubule, loop of Henle, distal convoluted tubule, Bowman's space, glomerulus glomerulus, Bowman's space, proximal convoluted tubule, loop of Henle, distal convoluted tubule, collecting duct glomerulus, Bowman's space, loop of Henle, proximal convoluted tubule, distal convoluted tubule, collecting duct glomerulus, Bowman's space, proximal convoluted tubule, distal convoluted tubule, loop of Henle, collecting duct Bowman's space, glomerulus, proximal convoluted tubule, distal convoluted tubule, loop of Henle, collecting duct

glomerulus, Bowman's space, proximal convoluted tubule, loop of Henle, distal convoluted tubule, collecting duct

Which part of the digestive tract is the predominant location for water and mineral absorption? midgut crop foregut hindgut

hindgut

You discover a new type of marine organism that has the kidneys of a fish but no gills. Based on what you know about other aquatic organisms, the newly discovered organism is _____ compared to the surrounding water. isotonic hypotonic hypertonic

hypotonic

Muscle contractions have _____ force at slower shortening contraction velocities compared to higher shortening contraction velocities. less stable equal decreased increased

increased

Atrioventricular valves separate the: aorta from the left ventricle. right and left ventricles. right atrium from the left atrium and the right ventricle from the left ventricle. left atrium from the left ventricle and the right atrium from the right ventricle.

left atrium from the left ventricle and the right atrium from the right ventricle.

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

less than 25%

When an individual has an energy surplus, he or she stores the extra energy as: nucleic acids. lipids. proteins. None of the answer options is correct. carbohydrates.

lipids.

A single motor neuron and the population of muscle fibers that it innervates is called a(n): excitation-contraction coupling. motor unit. neuromuscular junction. twitch fiber. motor endplate.

motor unit.

Which of the following relationships BEST describes the partial pressure of oxygen (pO2) in the lung (alveolar air), red blood cells, and blood plasma? pO2 lung < pO2 blood plasma < pO2 red blood cell pO2 red blood cell < pO2 blood plasma < pO2 lung pO2 blood plasma < pO2 lung < pO2 red blood cell pO2 red blood cell < pO2 lung < pO2 blood plasma

pO2 red blood cell < pO2 blood plasma < pO2 lung

Which process is responsible for creating MOST of an animal's nitrogenous waste? respiration toxins in the environment protein breakdown during metabolism consuming nitrogen in food

protein breakdown during metabolism

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

right atrium and right ventricle

Which of the following organisms would be able to extract the GREATEST percentage of oxygen from their respiratory medium? sparrows humans seagulls blue whales salmon

salmon

The initiation of the mammalian heart contraction: takes place at the SA node and requires neural input. takes place at the SA node. takes place at the AV node and requires neural input. requires neural input. takes place at the AV node.

takes place at the SA node.

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

the affinity of hemoglobin for O2 has decreased.

The partial pressure of a gas is: the difference in concentration of that gas inside and outside of a cell. the weight of a given volume of the gas. equivalent to the total atmospheric pressure. the fractional concentration of the gas multiplied by the overall, atmospheric pressure. a measure of how quickly a gas moves across a respiratory surface.

the fractional concentration of the gas multiplied by the overall, atmospheric pressure.

As fluid moves through a vessel, which factors determine the flow resistance? (Select all that apply.) the radius of the vessel the pressure exerted by the heart the length of the vessel the viscosity of the fluid

the radius of the vessel the length of the vessel the viscosity of the fluid

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

the return of excess interstitial fluid to the bloodstream

Metanephridia differ from protonephridia in all of the following ways EXCEPT that: fluid enters metanephridia through a funnel-shaped opening. fluid from the body cavity enters protonephridia without first being filtered. metanephridia are surrounded by an extensive capillary network, whereas protonephridia are not. selective reabsorption of materials occurs via cells lining the tubules in protonephridia and via capillaries in metanephridia. the urine produced in both systems is more dilute than the body fluids.

the urine produced in both systems is more dilute than the body fluids.

Cells can regulate their internal osmotic pressure by controlling the solute concentration inside of the cell. T/F

tru

During starvation, humans and other animals deplete glycogen and fat reserves first, followed by protein.

true

In most organisms, the excretion of wastes is closely tied to the maintenance of water and electrolyte balance.

true

Muscles produce higher forces when lengthening than when shortening. False True

true

The pancreas produces a variety of secretions, including: (Select all that apply.) trypsin for further protein digestion. gastrin to stimulate HCl production. lipase for fat digestion. methane from fermentation. bicarbonate ions to neutralize stomach acid.

trypsin for further protein digestion. lipase for fat digestion. bicarbonate ions to neutralize stomach acid.

Most mammals excrete _____; most aquatic animals excrete _____; birds, insects, and many reptiles excrete _____. urea; uric acid; ammonia urea; ammonia; uric acid ammonia; urea; uric acid uric acid; urea; ammonia uric acid; ammonia; urea

urea; ammonia; uric acid