Biology 117: Exam 3 Practice Questions

Identify parts on the nephron. Match numbers 1-4 in the diagram with the approproate labels. A. Proximal tubule B. Loop of Henle C. Renal corpuscle D. Distal Tubule

1 C. Renal corpuscle 2 A. Proximal tubule 3 B. Loop of Henle 4 D. Distal Tubule

Countercurrent exchange of gasses across lamellae of fish gills is efficient. Which of the following figures represents countercurrent exchange? A or B

A

The fetus developing inside a mother has hemoglobin with a higher affinity for oxygen than the mother. Which curve represents the fetus? A or B

A

In negative feedback mechanisms, ____________. (Select ALL that apply.) A. A physiological change causes responses that counteract the change and restore the original state. B. A physiological change causes responses that amplify the original change. C. Helps to maintain homeostasis. D. Disrupts homeostasis.

A. A physiological change causes responses that counteract the change and restore the original state. B. A physiological change causes responses that amplify the original change. C. Helps to maintain homeostasis.

Where to nitrogenous wastes come from? (Select ALL that apply.) A. Breakdown of proteins B. Breakdown of sugars C. Breakdown of fats D. Breakdown of nucleic acids

A. Breakdown of proteins D. Breakdown of nucleic acids

Blood sugar is maintained by negative feedback mechanisms. (See figure below.) The hormone secreted by the alpha cells of the pancreas that raises blood glucose after skipping a meal is ____________. A. Glucagon B. Epinephrine C. Insulin D. Cortisol

A. Glucagon

Mammalian red blood cells have approximately 280 million copies of the hemoglobin molecule. What is the role of hemoglobin in blood? A. It carries oxygen to tissues B. It carries carbon dioxide from tissues C. It carries both oxygen and carbon dioxide D. Its only function is to color the blood red

A. It carries oxygen to tissues

How does the osmolarity of kidney tissues change as you move from the cortex to the medulla? A. It increases B. It decreases C. It stays the same D. None of these

A. It increases

Why is cooperative binding important? A. It makes hemoglobin sensitive to small changes in oxygen demand, or PO2 (partial pressures of oxygen), of tissues. B. It allows hemoglobin to unload the four oxygen molecules independently of one another C. It makes hemoglobin less sensitive to changes in pH D. It enables hemoglobin to deliver smaller amounts of oxygen to tissues

A. It makes hemoglobin sensitive to small changes in oxygen demand, or PO2 (partial pressures of oxygen), of tissues.

Generally speaking, what do hormones do? (Select ALL that apply.) A. Maintain homeostasis B. Signal growth and development C. Catalyze chemical reactions D. Help with response to changing environments E. Act as chemical messengers

A. Maintain homeostasis B. Signal growth and development D. Help with response to changing environments E. Act as chemical messengers

Which of the following organisms would lose the most water by osmosis across it gills? A. Marine bony fish B. Freshwater bony fish C. Freshwater invertebrate D. All will lose water across their gills equally. E. None of these lose water across gills.

A. Marine bony fish

There is ______ oxygen unloaded into working tissues from hemoglobin with cooperative binding. A. More B. Less C. About the same amount of

A. More

Hormones can be from one of several chemical families. Which of the following is NOT a chemical family of a hormone? (Select ALL that apply.) A. Sugars B. Steroids C. Nucleic acids D. Amino acid derivatives E. Peptides and polypeptides

A. Sugars D. Amino acid derivatives

Which of the following describes how osmosis occurs across a cell membrane? A. Water moves from an area of low solute concentration to an area of high solute concentration. B. Water moves from an area of high solute concentration to an area of low solute concentration. C. Solutes move from a high water concentration to an area of low water concentration. D. Solutes move from an area of low solute concentration to an area of high solute concentration. E. Both water and solutes move across the cell membrane from an area of high concentration to an area of low concentration.

A. Water moves from an area of low solute concentration to an area of high solute concentration.

Which form of nitrogenous waste requires the most water for dilution? A. ammonia B. uric acid C. nitrogen gas D. urea E. All forms of nitrogenous waste require similar amounts of water to dilute them to non-toxic concentrations

A. ammonia

White blood cells called T-cells synthesize and release interleukin 2, a molecule that activates T-cells and causes those T-cells to repeatedly divide. A. autocrine B. endocrine C. neural D. neuroendocrine

A. autocrine

Which components of blood do not normally enter Bowman's capsule from the glomerulus? A. blood cells B. sodium ions C. urea D. water E. nutrients

A. blood cells

Together, the respiratory and circulatory systems function to supply tissues with the ____________ required to complete cellular respiration while removing the ____________ produced as a by-product of this process. A. oxygen; carbon dioxide B. nitrogen; oxygen C. oxygen; nitrogen D. carbon dioxide; oxygen

A. oxygen; carbon dioxide

Starting from the filtrate of blood, give the pathway of pre-urine processing in terrestrial vertebrates. A. renal corpuscle, proximal tubule, loop of Henle, distal tubule, collection duct B. renal corpuscle, distal tubule, loop of Henle, proximal tubule, collection duct C. collection duct, proximal tubule, distal tubule, loop of Henle, renal corpuscle D. renal corpuscule, collection duct, proximal tubule, distal tubule, loop of Henle E. proximal tubule, loop of Henle, distal tubule, renal corpuscule, loop of Henle

A. renal corpuscle, proximal tubule, loop of Henle, distal tubule, collection duct

What is the path of blood flow in an organism with a double circulatory (2-curcuit) system? A. right atrium → right ventricle → pulmonary circuit → left atrium → left ventricle B. right atrium → left atrium → pulmonary circuit → right ventricle → left ventricle C. left atrium → left ventricle → pulmonary circuit → right atrium → right ventricle D. pulmonary circuit → right atrium → left atrium → left ventricle → right ventricle E. right atrium → right ventricle → left atrium → left ventricle → pulmonary circuit

A. right atrium → right ventricle → pulmonary circuit → left atrium → left ventricle

In order to maximize the rates of diffusion for gasses, indicate whether you would want to increase or decrease the following variables in Fick's Law. (You may reuse the choices and many times as you like.) Rate of Diffusion = k x A x (P2 - P1)/D A: P2-P1: D: A. increase B. decrease C. neither

A: increase P2-P1: increase D: decrease

Are under higher pressure

Arteries

Have very thick wall

Arteries

According to the percentages in the figure, how much oxygen from water diffuses into fish gills during countercurrent exchange? A. 100% B. 85% C. 50% D. 10% E. 0%

B. 85%

Oxygen will diffuse faster from blood to tissues faster in response to which of the following conditions? A. An increase in the partial pressure of oxygen in the tissue B. A decrease in the partial pressure of oxygen in the tissue C. An increase in the thickness of the capillary wall D. A decrease in the surface area of the capillary

B. A decrease in the partial pressure of oxygen in the tissue

The products of filtration in the renal corpuscle enter the renal tubule through which of the following structures? A. the loop of Henle B. Bowman's capsule C. the proximal convoluted tubule D. the collecting duct

B. Bowman's capsule

Which of the following organisms would you expect to have the highest concentrations of proteins that protect cells from the toxic effects of ammonia? A. Terrestrial reptile B. Freshwater bony fish C. Mammal D. Insect E. Bird

B. Freshwater bony fish

Endocrine glands and tissues release: A. Nucleic acids B. Hormones C. Neurotransmitters D. Polysaccharides

B. Hormones

Hormones have a role in regulation of many different physiological functions. Most hormones are regulated by __________. A. Positive feedback B. Negative feedback C. Both positive and negative feedback D. Neither positive nor negative feedback

B. Negative feedback

Which side is hypertonic relative to the other? A. The left is hypertonic B. The right is hypertonic C. They are isotonic

B. The right is hypertonic

In the descending limb of the loop of Henle, which of the following helps explain the water movement out of the pre-urine solution and into the surrounding kidney tissues? (Select ALL that apply.) A. Water is moving by active transport mechanisms B. Water is moving passively by osmosis C. The osmolarity of the surrounding kidney tissues is high D. The osmolarity of the surrounding kidney tissues is low

B. Water is moving passively by osmosis C. The osmolarity of the surrounding kidney tissues is high

The cells of the pancreas release two hormones to help keep the levels of glucose in the blood close to a set point. Which of the following is true about this negative feedback system? A. When insulin levels are high, glucagon levels are high B. When insulin levels are high, glucacon levels are low C. Insulin is released in response to low levels of glucose in the blood D. Insulin stimulates the liver to break down glycogen into glucose

B. When insulin levels are high, glucacon levels are low

Can cells respond to multiple hormones? A. Yes, but only if hormones arrive at the cell at different times. B. Yes, if they have receptors for each of the hormones. C. No, a cell is only able to respond to one hormone.

B. Yes, if they have receptors for each of the hormones.

The epithelial cells of fish gills have membrane proteins involved in maintaining salt balance. Would you expect these cells to have many mitochondria? A. No; salts will diffuse according to concentration gradients to maintain osmotic balance of the fish and diffusion does not require energy (ATP) inputs. B. Yes; fish need to actively transport salts in or out of tissues to maintain osmotic balance and active transport requires ATP generated by mitochondria. C. Yes; salts will diffuse according to concentration gradients to maintain osmotic balance of the fish and diffusion requires ATP generated by mitochondria. D. No; fish need to actively transport salts in or out of tissues to maintain osmotic balance and active transport does not require energy (ATP) inputs.

B. Yes; fish need to actively transport salts in or out of tissues to maintain osmotic balance and active transport requires ATP generated by mitochondria.

If you are hiking through the desert for several days, which of the following should you drink to ensure proper hydration? A. bottled water that had been frozen to ensure that it would be as cold as possible B. a drink with a combination of water and electrolytes C. caffeinated beverages D. bottled water kept at room temperature

B. a drink with a combination of water and electrolytes

Identify the conditions that would cause a cell to dehydrate. A. an isotonic external environment B. a hypertonic external environment C. a hypertonic internal environment D. hypotonic external environment E. isotonic internal environment

B. a hypertonic external environment

Hormones from the anterior pituitary ____________. A. are produced in the hypothalamus, but released by the anterior pituitary B. are produced and released by the anterior pituitary C. are produced by the anterior pituitary, but released by the hypothalamus D. are produced in the posterior pituitary, but released by the anterior pituitary.

B. are produced and released by the anterior pituitary

Anterior pituitary gland located at the base of the brain releases prolactin, which travels through the bloodstream and stimulates mammary gland growth and milk production in females. A. autocrine B. endocrine C. neural D. neuroendocrine

B. endocrine

Erythropoietin (EPO) is released by cells in the kidney. It promotes production of red blood cells from precursor cells in bone marrow. Synthetic EPO is used to treat certain forms of anemia. It has also been used by athletes trying to gain an edge over the competition in endurance sports (against regulations, of course). A. autocrine B. endocrine C. neural D. neuroendocrine

B. endocrine

The necropsy (postmortem analysis) of a freshwater fish that died after being placed accidentally in saltwater would likely show that _____. A. the kidneys were not able to keep up with the water removal necessary in this hyperosmotic environment, creating an irrevocable loss of homeostasis B. loss of water by osmosis from cells in vital organs resulted in cell death and organ failure C. high amounts of salt had diffused into the fish's cells, causing them to swell and lyse D. the gills became encrusted with salt, resulting in inadequate gas exchange and a resulting asphyxiation E. brain cells lysed as a result of increased osmotic pressure in this hyperosmotic environment, leading to death by loss of autonomic function

B. loss of water by osmosis from cells in vital organs resulted in cell death and organ failure

Hormones from the posterior pituitary are ____________ signals. A. endocrine B. neuroendocrine C. neural D. pheromone E. paracrine

B. neuroendocrine

What would be the consequences if we were to reverse the direction of water flow over the gills of a fish, moving water inward past the operculum, past the gills, then out of the mouth? This reversal of water flow would ________. A. change the exchange of gases in the body from carbon dioxide out and oxygen into carbon dioxide in and oxygen out B. reduce the efficiency of gas exchange C. increase the efficiency of gas exchange

B. reduce the efficiency of gas exchange

The force driving simple diffusion is ________, while the energy source for active transport is ________. A. transmembrane pumps; electron transport B. the concentration gradient; ATP C. the concentration gradient; ADP D. phosphorylated protein carriers; ATP

B. the concentration gradient; ATP

Salmon and sea bass are useful for studies of the role of the gills in osmoregulation in fishes because ________. A. they are unique fishes that osmoconform to seawater B. they live in freshwater and in seawater at different life history stages C. they both feed on marine invertebrates, increasing their salt intake D. they excrete extremely high levels of salts in freshwater environments

B. they live in freshwater and in seawater at different life history stages

The lipid bilayer below is impermeable to solutes. Which way will water move? A. <<--- to the left B. to the right --->> C. equally in both directions <-- --> D. It will not move at all

B. to the right --->>

Biologists recently have been able to produce mice that lack functioning genes for aquaporins. How does their urine compare to that of individuals with normal aquaporins? A. Lower volume and lower osmolarity B. Lower volume and higher osmolarity C. Higher volume and lower osmolarity D. Higher volume and higher osmolarity

C. Higher volume and lower osmolarity

What effect does ADH (antidiuretic hormone) have on the nephron? A. It increases water permeability of the descending limb of the loop of Henle. B. It decreases water permeability of the descending limb of he loop of Henle. C. It increases the water permeability of the collecting duct D. It decreases the water permeability of the collecting duct. E. None of the answers are correct.

C. It increases the water permeability of the collecting duct

Which of the following most accurately describes selective permeability? A. There must be a concentration gradient for molecules to pass through a membrane. B. An input of energy is required for transport. C. Only certain molecules can cross a cell membrane. D. Lipid-soluble molecules pass through a membrane

C. Only certain molecules can cross a cell membrane.

Many athletes have tried to enhance their performance by taking anabolic steroids that mimic the naturally occurring testosterone steroid hormones in the body. Testosterone can help build muscle by ____________. (Hint: Think in general about what steroid hormones do.) A. Promoting catabolic reactions (reactions that break down molecules) B. Switching off negative feedback mechanisms C. Promoting transcription of muscle-growth genes D. Activating existing intracellular proteins and enzymes

C. Promoting transcription of muscle-growth genes

The cells that initiate contraction in the vertebrate heart are located at the SA (sinoatrial) node. The signal from the SA node is delayed at the AV (atrioventricular) node. Which of the following explains the delay? A. The delay ensures atria and ventricles are both filled with blood before contraction. B. The delay allows time for blood in the left side to move to the right side before it contracts. C. The delay allows time for blood in the atria to move to the ventricles before they contract. D. The delay prevents blood from being pumped backward through the heart.

C. The delay allows time for blood in the atria to move to the ventricles before they contract.

Which of the following statements is true regarding marine osmoregulators (e.g. organisms living in ocean environments, balancing water and salts in their systems)? A. They include only marine invertebrates. B. They are isosmotic with their environments. C. They tend to lose water to their environment. D. They actively take in salt via gills or other structures. E. All answers are correct.

C. They tend to lose water to their environment.

Animals produce waste, even very young ones. Which type of nitrogenous waste would you expect to find produced by embryos inside eggs laid on land? (Hint: Think about what you know about toxicity and solubility of nitrogenous wastes.) A. Ammonia B. Urea C. Uric acid D. Any of these would be equally likely; it varies by species

C. Uric acid

Which of the following types of nitrogenous wastes released by animals needs the least amount of water? A. Ammonia B. Urea C. Uric acid D. These all need similar amounts of water to be excreted from the body.

C. Uric acid

Which one of the following statements is true of fishes that live in freshwater? A. The environment is isosmotic with respect to their tissues. B. They lose water to their environment primarily through the gills. They replace this water by drinking. C. Water enters epithelial cells in their gills via osmosis. Electrolytes leave the same cells via diffusion. D. They have specialized cells that actively pump salts from their tissues into the environment.

C. Water enters epithelial cells in their gills via osmosis. Electrolytes leave the same cells via diffusion.

In the brain, dopamine is a chemical signal that gets passed from one neuron to the next. While it has many roles in animal physiology, it is most known for mediating feelings of pleasure. A. autocrine B. endocrine C. neural D. neuroendocrine

C. neural

Which of the following is the destination for blood traveling through the pulmonary artery? A. the pulmonary vein B. the right atrium C. the lungs D. the left atrium E. the left ventricle

C. the lungs

What is the function of the osmotic gradient found in the kidney? The osmotic gradient allows for _____. A. the filtration of large cells at the glomerulus B. electrolytes to move from low to high concentrations in the absence of ATP C. the precise control of the retention of water and electrolytes D. the loop of Henle to deliver water to the renal vein

C. the precise control of the retention of water and electrolytes

Why is it necessary for arterioles to constrict and dilate? A. to absorb oxygen into blood B. to increase blood volume C. to help maintain consistent blood pressure D. to regulate the rhythm of the heartbeat E. All answers are correct

C. to help maintain consistent blood pressure

Gas exchange is more difficult for aquatic animals with gills than for terrestrial animals with lungs because _____. A. gills allow only unidirectional transport B. gills collapse in air C. water contains much less oxygen per unit volume than air D. water is less dense than air E. gills have less surface area than lungs

C. water contains much less oxygen per unit volume than air

Consider the various structures animals have for exchanging gasses. In order to maximize the diffusion for gasses from one area to another, you would want _____________________. A. Large surface area, large difference in partial pressures between the two areas, and a thickbarrier of diffusion B.Small surface area, small difference in partial pressures between the two areas, and a thin barrier of diffusion C.Large surface area, large difference in partial pressures between the two areas, and a thinbarrier of diffusion D. Small surface area, large difference in partial pressures between the two areas, and a thinbarrier of diffusion E.Large surface area, small difference in partial pressures between the two areas, and a thinbarrier of diffusion

C.Large surface area, large difference in partial pressures between the two areas, and a thin barrier of diffusion

Have a small diameter, approximately the diameter of a single red blood cell

Capillaries

Some types of hormones are lipid soluble and others are not. Lipid soluble hormones usually bind to receptors ____________. A: embedded within the cell membrane B: inside the cell C: and alter gene expression D. A and C D. B and C E. A and/or B F. All of the above

D. B and C

Which of the following is an osmoregulatory challenge that saltwater fishes need to overcome? A. Diffusion of sodium ions out of the gills and body B. Low intake of water into the body C. High urine excretion from the kidneys D. Diffusion of water out of the gills and body surfaces

D. Diffusion of water out of the gills and body surfaces

Hyperthyroidism Part 2: Hyperthyroidism a condition is characterized by symptoms such as weight loss, feelings of anxiety and irritability, and an increased sensitivity to heat. In normal function, the pituitary gland releases thyroid-stimulating hormone (TSH) to signal the thyroid to release the thyroid hormone thyroxine. The pituitary stops releasing TSH when thyroxine levels are adequate. What would you expect to find in a person with hyperthyroidism caused by Grave's disease, an autoimmune disorder that affects the thyroid? A. Low levels of thyroxine, low levels of TSH B. Low levels of thyroxine, high levels of TSH C. High levels of thyroxine, high levels of TSH D. High levels of thyroxine, low levels of TSH

D. High levels of thyroxine, low levels of TSH

Which of the following organisms would you expect to have nephrons with very long loops of Henle in their kidneys (relative to the others listed). A. Freshwater fish B. Humans C. Beavers living in/near a river D. Kangaroo rats of the desert

D. Kangaroo rats of the desert

Which is not part of the reason that insects today are smaller than the very large Paleozoic insects? A. Insects rely on a system of tubes called tracheae for gas exchange, which limits rates of diffusion of oxygen to the body's tissues compared to other respiratory systems. B. Body size in insects will depend in part on the ability of the insect to provide adequate oxygen to maintain healthy body tissues. C. There was twice as much oxygen in the atmosphere during the Paleozoic era, permitting greater rates of respiration and growth. D. Paleozoic insects competed with large amphibians for food resources.

D. Paleozoic insects competed with large amphibians for food resources.

What would happen to a red blood cell in isotonic solution? A. It would shrivel. B. It would shrivel and then swell. C. It would burst open. D. The red blood cell would not change when placed in the solution. E. It would decrease in size.

D. The red blood cell would not change when placed in the solution.

In insects, what is the adaptive significance of spiracles? A. They open and close during flight or other types of movement, so function as a "breathing" mechanism. B. They open into the body cavity, allowing direct contact between hemolymph and tissues. C. They are thin and highly branched, so offer a large surface area for gas exchange. D. They close off tracheae to minimize water loss.

D. They close off tracheae to minimize water loss.

Which statement describes hemoglobin's cooperativity? A. When hemoglobin binds one oxygen molecule, its shape changes, which reduces its affinity for binding more oxygen molecules. B. When oxygen is present in blood, the shape of hemoglobin changes to allow oxygen to bind to it. C. When the oxygen concentration of blood decreases, hemoglobin changes its shape to retain oxygen more readily. D. When hemoglobin binds one molecule of oxygen, its shape changes to make it bind more readily to a second, third, and fourth oxygen molecule. E. None of the answers accurately describe the cooperativity of hemoglobin

D. When hemoglobin binds one molecule of oxygen, its shape changes to make it bind more readily to a second, third, and fourth oxygen molecule.

Name the simplest and most toxic nitrogenous waste excreted by animals. A. sodium chloride B. uric acid C. urea D. ammonia E. both uric acid and urea

D. ammonia

Blood in __________________. A. veins is always deoxygenated while in arteries it is always oxygenated. B. arteries is always oxygenated while in veins it is always deoxygenated. C. veins is flowing away from the heart while in arteries it is flowing toward the heart. D. arteries is flowing away from the heart while in veins it is flowing toward the heart. E. None of the answers above is correct

D. arteries is flowing away from the heart while in veins it is flowing toward the heart.

Which of the following pairs of organisms excrete nitrogenous wastes in the form of uric acid? A. humans and frogs B. fish and turtles C. lions and horses D. insects and birds E. mice and birds

D. insects and birds

Growth hormone (GH) is produced by neurons that originate in the hypothalamus of the brain. GH acts on many cells and tissues throughout the body to promote cell division and growth. A. autocrine B. endocrine C. neural D. neuroendocrine

D. neuroendocrine

Which of the following statements regarding osmosis is accurate? A. If a cell is placed in a hypotonic solution, water will move into the cell. B. If a cell is placed in a hypertonic solution, water will move out of the cell. C. If a cell is placed in an isotonic solution, there will be no net movement of water. D. Water molecules move in both directions across a cell membrane even if the cell and surrounding environment are isotonic. E. All answers are correct.

E. All answers are correct.

What are the structures in lungs that facilitate gas exchange called? A. Ventricles B. Tracheae C. Bronchi D. Atria E. Alveoli

E. Alveoli

Hyperthyroidism Part 1: Hyperthyroidism is a condition characterized by symptoms such as weight loss, feelings of anxiety and irritability, and an increased sensitivity to heat. In normal function, the pituitary gland releases thyroid-stimulating hormone (TSH) to signal the thyroid to release the thyroid hormone thyroxine. The pituitary stops releasing TSH when thyroxine levels are adequate. Which of the following are possible causes of hyperthyroidism? A: The thyroid is not producing adequate amounts of thyroxine. B: The thyroid is producing too much thyroxine. C: There is a tumor on the pituitary causing it to release too much TSH. D. A and C E. B and C

E. B and C

Which group of animals most likely excretes the largest volume of urine relative to their body size? A. marine fish B. reptiles C. mammals D. birds E. Freshwater fish

E. Freshwater fish

True or False: All animals take in CO2 needed for cellular respiration from the environment and release O2.

False

In humans, the hormone melatonin is released by the pineal gland located in the center of the brain. It is involved in maintaining sleep-wake cycles in response to light availability. It is an amine, so the receptors are likely [a] and it likely [b]. A. embedded within the cell membrane B. inside the cell C. alters gene expression by affecting transcription D. alters second messengers or enzyme activity

In humans, the hormone melatonin is released by the pineal gland located in the center of the brain. It is involved in maintaining sleep-wake cycles in response to light availability. It is an amine, so the receptors are likely embedded within the cell membrane and it likely alters second messengers or enzyme activity.

The amount of oxygen unloaded from hemoglobin into tissues with a PO2 of 45 mm Hg would be [x] with cooperative binding and [y] without cooperative binding. A. 80% B. 70% C. 55% D. 30% E. 20%

The amount of oxygen unloaded from hemoglobin into tissues with a PO2 of 45 mm Hg would be 30% with cooperative binding and 20% without cooperative binding.

True or False: All animals rely on diffusion for the exchange of gasses with their various environments

True

True or False: Terrestrial animals have a 2-circuit circulatory system because the pressures needed overcome gravity and pump blood to all parts of the body are too high for the more delicate lung tissues.

True

True or false: Hormones are released by glands or tissues in the endocrine system, then travel through the bloodstream to reach target cells.

True

Are under lower pressure

Veins

Have one way valves to prevent backflow

Veins