Bio 212 Final Exam

At the summit of a high mountain, the atmospheric pressure is 380 mm Hg. If the atmosphere is still composed of 21percent oxygen, then the partial pressure of oxygen at this altitude is about _____. A) 80 mm Hg B) 160 mm Hg C) 0 mm Hg D) 380 mm Hg E) 760 mm Hg

A

During oogenesis meiosis results in _____. A) two or three small cells and one large cell that develops further if fertilized B) four equally sized cells that stop dividing in meiosis I C) two equally sized cells that are both typically fertilized D) two equally sized cells, but only one is typically fertilized

A

Fertilization of a human egg takes place in the _____. A) oviduct B) cervix C) ovary D) vagina E) uterus

A

Large proteins such as albumin remain in capillaries rather than diffusing out, resulting in the _____. A) development of an osmotic pressure difference across capillary walls B) loss of osmotic pressure in the capillaries C) increased diffusion of carbon dioxide D) loss of fluid from capillaries E) increased diffusion of hemoglobin

A

Some animals have no gills when young, but then develop gills that grow larger as the animal grows larger. What is the reason for this increase in gill size? A) Relative to their volume, the young have more surface area across which they can transport all the oxygen they need. B) The young have a higher basal metabolic rate. C) The young of these animals are much more active than the adult, which leads to a higher BMR (basal metabolic rate) and, therefore, a higher need for oxygen. D) Relative to their surface area, the young have more body volume in which they can store oxygen for long periods of time.

A

To become bound to hemoglobin for transport in a mammal, atmospheric molecules of oxygen must cross _____. A) five membranes—in and out of the cell lining the lung, in and out of the endothelial cell lining an alveolar capillary, and into the red blood cell—to bind with hemoglobin B) one membrane—that of the lining in the lungs—and then bind directly to hemoglobin, a protein dissolved in the plasma of the blood C) zero membranes—oxygen binds directly to hemoglobin, a protein dissolved in the plasma of the blood D) two membranes—in and out of the cell lining the lung—and then bind directly to hemoglobin, a protein dissolved in the plasma of the blood E) four membranes—in and out of the cell lining the lung, in and out of the endothelial cell lining an alveolar capillary—and then bind directly to hemoglobin, a protein dissolved in the plasma of the blood

A

What is a disadvantage of viviparity? A) Limited number of offspring B) Decreased likelihood of surviving to birth C) Eggs are not well protected after laying. D) Mothers have to produce all the nutrition required by the embryo prior to egg laying.

A

Why is progesterone production in the corpus luteum important in the first trimester of pregnancy? A) To maintain the uterine lining B) To produce milk C) To provide nutrition to the embryo D) To regulate the heartbeat of the fetus

A

Which of the following correctly pairs the vessel type with its characteristic? a. Artery - tough, thick-walled vessel b. Vein - takes blood away from the heart c. Capillary - returns blood toward the heart d. Vein - allows gas exchange between blood and tissues e. I do not know

A As blood flows away from the heart, it is pumped to the rest of the body through arteries and is under relatively higher blood pressure. Artery walls are made of smooth muscle that regulates blood flow. Comparatively, veins have thinner walls and the blood is under relatively low pressure as it returns to the heart.

A disease results in fetal blood having a lower affinity for oxygen than the mother's blood. What can we expect to happen? a. The fetus will die, it will not receive enough oxygen from maternal blood b. The fetus will live, it can extract oxygen from amniotic fluid c. The fetus will die, it will not be able to get rid of CO2 d. The fetus will live, the fetus normally has lower affinity blood e. I do not know

A In order for the fetus to be able to acquire oxygen from the maternal circulation, the fetal hemoglobin must be able to pull oxygen away from the maternal hemoglobin. This requires that the fetal hemoglobin have a higher affinity for oxygen than the maternal hemoglobin. Oxygen is not extracted from the amniotic fluid. Most of the CO2 is transported in the form of bicarbonate in the plasma of the blood.

Beginning in the toes, which one of the following provides the proper path the deoxygenated blood would have to take to reach the systemic circulation? (Some steps in the path may not be included). a. Inferior vena cava, right atrium, pulmonary artery, left ventricle, aorta b. Inferior vena cava, left atrium, pulmonary artery, right ventricle, aorta c. Inferior vena cava, right atrium, pulmonary vein, aorta, left ventricle d. Superior vena cava, left atrium, pulmonary vein, right ventricle, aorta e. I do not know

A Starting at the toes the blood travels back up to the heart via the inferior vena cava. From the inferior vena cava the blood will travel through the right atrium and ventricle to the pulmonary artery to reach the lungs. After being re-oxygenated, the blood will travel back to the heart via the pulmonary vein. The blood will travel through the left atrium to the left ventricle and finally to the aorta.

During respiration the volume of the lungs change and the diaphragm contracts and relaxes to allow for maximum air intake and gas exchange. During inhalation what is the state of the lungs and diaphragm? a. The lungs volume increases, the diaphragm is contracted b. The lungs volume decreases, the diaphragm is relaxed c. The lungs volume increases, the diaphragm is relaxed d. The lungs volume decreases, the diaphragm is contracted e. I do not know

A The diaphragm contracts (resulting in downward movement) thus enlarging the lung cavity. This negative pressure allows air to flow into the lungs and lung volume increases.

Each hemoglobin molecule contains four heme subunits. Which element is responsible for these subunits' ability to bind O2? a. Fe2+ b. CN- c. Pb2+ d. PO3+ e. I do not know

A The oxygen binding component of heme is the associated iron (Fe2+) atom. Cyanide, a poison, will bind in place of oxygen and block heme's ability to bind oxygen. Pb is lead, also a poison. Phosphate groups serve a lot of functions in biological systems, but they are not the active component of heme.

A rabbit taken from a meadow near sea level and moved to a meadow high on a mountainside would have some trouble breathing. Why? A) The percentage of oxygen in the air at high elevations is higher than at sea level. B) The partial pressure of oxygen in the air at high elevations is lower than at sea level. C) The percentage of oxygen in the air at high elevations is lower than at sea level. D) The partial pressure of oxygen in the air at high elevations is higher than at sea level.

B

Asexual reproduction results in offspring that are genetically identical to their parent. What type of cell process occurs to generate this type of offspring? A) cell fusion B) mitosis C) meiosis

B

Determine the rate of diffusion in the gas-exchange organ of an air-breathing animal where the area for gas exchange in the lung is 200 mm2, the diffusion constant is 0.08, the PO2 (partial pressure of oxygen) of the air in the lung is 140 mm Hg, the PO2 in blood flowing into the lung is 90 mmHg, and the thickness of the gas exchange membrane is 0.001 mm. A) 125 B) 800,000 C) 10,000,000 D) 00032

B

How does "the pill" work to prevent pregnancy? A) It blocks the oviduct, preventing passage of eggs or sperm. B) It delivers progesterone leading the ovary to discontinue ovulating a new oocyte. C) It produces an acidic environment for sperm. D) It is a barrier between the vagina and the cervix.

B

In hormone production, how do the follicle and corpus luteum compare? A) The follicle produces mostly progesterone; the corpus luteum produces estradiol and progesterone. B) The follicle produces more estradiol than progesterone; the corpus luteum produces more progesterone than estradiol. C) Both produce primarily estradiol. D) Both produce primarily progesterone.

B

The sun shining on a tidal pool during a hot day heats the water. As some water evaporates, the pool becomes saltier, causing _____. A) an increase in its ability to sustain aerobic organisms B) a decrease in its oxygen content C) a decrease in the water's density D) an increase in its carbon dioxide content

B

Which of the following reactions prevails in red blood cells traveling through alveolar capillaries? (Hb = hemoglobin) A) CO2 + H2O → H2CO3 B) Hb + 4 O2 → Hb(O2)4 C) H2CO3 → H+ + HCO3- D) Hb + 4 CO2 → Hb(CO2)4 E) Hb(O2)4 → Hb + 4 O2

B

2015 has been reported as the warmest year on record. Consider what would happen if the increase in air temperature also resulted in an increase in water temperature. which of the following is a possible outcome? a. Aquatic ventilation becomes easier b. Aquatic ventilation becomes harder c. Oxygen available in water increases d. Oxygen available in water remains the same e. I do not know

B As the temperature of water increases, the amount of gas that dissolves in it decreases. If a previously cold-water environment suddenly had warmer water, the fish would have a harder time obtaining the required amount of oxygen because there would be less gas, and therefore oxygen, in the water.

The act of ventilation in mammals is made possible by which of the following? a. Air being pulled in by flexing of the lungs b. Negative pressure due to contraction of the diaphragm c. Transfer of oxygen across the alveolar membrane d. Positive pressure due to contraction of the diaphragm e. I do not know

B Mammalian lungs work by negative pressure. When the diaphragm muscles contract, the diaphragm moves downward, enlarging the lung cavity. This creates negative pressure and allows air to move into the lungs. The lungs are largely passive in this process. Transfer of oxygen across the alveolar membrane and exchange of carbon dioxide and oxygen in the capillaries are both gas exchange.

A rupture in the thoracic cavity, that exposes the internal cavity to the outside air, can result in which of the following? a. Increase in gas diffusion b. Collapsed lung c. Disequilibrium between internal and external pressures e. I do not know

B Since mammalian lungs inflate due to negative pressure created when the diaphragm moves downward, if the lung cavity is exposed to outside air, no negative pressure is created and the lungs will not inflate.

A major difference between mammalian spermatogenesis and oogenesis is _____. A) the number of meiotic divisions needed to form gametes B) the ploidy of the gametes C) the timing of gamete formation D) All of the above are correct.

C

Carbon dioxide levels in the blood and cerebrospinal fluid affect pH. This enables the organism to sense a disturbance in gas levels as _____. A) the medulla oblongata is able to control the concentration of bicarbonate ions in the blood B) the brain directly measures and monitors oxygen levels and causes breathing changes accordingly C) the medulla oblongata, which is in contact with cerebrospinal fluid, monitors pH and uses this measure to control breathing D) stretch receptors in the lungs cause the medulla oblongata to speed up or slow breathing E) the brain alters the pH of the cerebrospinal fluid to force the animal to retain more or less carbon dioxide

C

In an animal that switches between sexual and asexual reproduction, when is sexual reproduction more likely to occur? A) when conditions for survival are favorable B) when males and females find each other C) when conditions for survival are unfavorable D) What conditions favor sexual over asexual remains a complete mystery.

C

Which of the following statements best describes the difference between non-cooperative and cooperative binding of oxygen by hemoglobin? a. Non-cooperative binding increases the total saturation of oxygen for a given change in partial pressures b. Non-cooperative binding allows for more oxygen to be delivered to both resting and exercising tissues c. Cooperative binding allows for more oxygen to be delivered to both resting and exercising tissues because the amount of change in oxygen loading is increased for a given change in partial pressures d. Cooperative binding requires a higher oxygen saturation of hemoglobin for resting tissues e. I do not know

C Cooperative binding allows for more oxygen to be delivered to both resting and exercising tissues because it incorporates hemoglobin's high sensitivity to changes in PO2 in tissues. The sigmoidal shape of the curve illustrates cooperative binding. It shows that less oxygen saturation changes rapidly over the physiological ranges of both resting and active tissues.

Which of the following is an adaptation found in amphibians and some reptiles for gas exchange? a. A crosscurrent system b. An open circulatory system c. A pulmocutaneous system d. A countercurrent system e. I do not know

C In some amphibians and reptiles, the circulatory system is able to shunt circulation to the skin when the animal submerges. This allows for some gas exchange. The pulmonary circulation is through the lungs and cutaneous refers to the skin. Open circulatory systems are found in animals, such as insects, that have hemolymph. Countercurrent gas exchange is found in fish. It allows for efficient gas exchange in water which contains less dissolved gas than in air.

Which of the following explanations is correct for why it is easier to breathe at sea level compared to at the peak of Mount Everest? a. The partial pressure of oxygen is much higher at the top of Mount Everest, which makes the air much harder to inhale b. The partial pressure of oxygen is much higher at sea level, which makes the oxygen less likely to diffuse into the tissues c. The partial pressure of oxygen is much lower at the top of Mount Everest, which makes the oxygen less likely to diffuse into the tissues d. The partial pressure of oxygen is much lower at sea level, because oxygen is less soluble in water e. I do not know

C It is harder to breathe at the top of Mt. Everest because the partial pressure of oxygen is so much lower than the partial pressure of oxygen at sea level. The low partial pressure of oxygen decreases the rate of diffusion of oxygen from the environment to the lung tissue, making it harder for us to get the oxygen we need for respiration.

Which of the following is true about partial pressures? a. Rates of diffusion remain the same regardless of atmospheric pressure b. Gas percentages fluctuate with atmospheric pressure c. At lower atmospheric pressure, partial pressures are lower d. At higher atmospheric pressures, partial pressures are lower e. I do not know

C Partial pressure of a gas is the amount of the total pressure contributed by the given gas. This is calculated by taking the percentage of the gas in the total mixture (expressed as the decimal) times the total pressure. This is a direct relationship so at lower total pressure (atmospheric pressure in this case) the partial pressure is lower. Rates of diffusion are affected by pressure. The gas percentages (gas composition) do not change as the total pressure changes.

For a sloth the required rate of diffusion of oxygen is less than the required rate of diffusion of oxygen for a cheetah due to the differences in the speed of their movements and oxygen requirements. What variable of Fick's law of diffusion is likely different between these two animals? Fick a. k b. P2 c. P1 d. D e. I do not know

C The partial pressure of oxygen in a cheetah's muscle tissue (P2) is likely to be much lower than a sloth due to the demands of running when chasing prey. Since both are mammals, the thickness of the lung alveoli and blood vessel walls is likely to be similar between the two species.

As mountaineers climb to higher altitudes, they often fatigue more quickly due to a change in the atmospheric conditions. Which of the following is the correct explanation of this change? a. The percentage of oxygen molecules in the air decreases b. The amount of nitrogen in the air increases c. The total amount of molecules in the air decreases d. The percentage of oxygen molecules in the air increases e. I do not know

C The percentage of oxygen in the atmosphere does not vary with elevation and pressure. Instead, there are far fewer molecules of oxygen and other atmospheric gases present at higher altitudes compared to at sea level because of less atmospheric pressure. While the percentage of oxygen in the air does not change, the partial pressure of oxygen does.

Which of the following is NOT true about an open circulatory system? a. Hemolymph is not confined to the circulatory system b. Molecules are exchanged directly from hemolymph and tissues c. Open circulatory systems do not have vessels d. Hemolymph is under relatively low pressure e. I do not know

C While the vessels are not continuous as in closed circulatory systems, open circulatory systems still have a vascular system to move hemolymph throughout the body. These vessels then open up into fluid-filled cavities to allow hemolymph to come in direct contact with tissues.

At an atmospheric pressure of 870 mm Hg with 21 percent oxygen, the partial pressure of oxygen is _____. A) 219 mm Hg B) 127 mm Hg C) 151 mm Hg D) 182 mm Hg E) 100 mm Hg

D

Peaks of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) production occur during _____. A) the secretory phase of the menstrual cycle B) the menstrual flow phase of the uterine cycle C) the beginning of the follicular phase of the ovarian cycle D) the period just before ovulation E) the end of the luteal phase of the ovarian cycle

D

The surgical removal of the seminal vesicles would likely _____. A) cause the testes to migrate back into the abdominal cavity B) enhance the fertilization potency of sperm in the uterus C) cause sterility because sperm would not be produced D) greatly reduce the volume of semen E) cause sterility because sperm would not be able to exit the body

D

What embryo-produced hormone maintains progesterone and estrogen secretion by the corpus luteum through the first trimester of pregnancy? A) progesterone B) luteinizing hormone (LH) C) gonadotropin-releasing hormone (GnRH) D) human chorionic gonadotropin (hCG) E) follicle-stimulating hormone (FSH)

D

What would occur if follicle-stimulating hormone levels were inhibited? A) The lining of the uterus would remain thickened. B) Estradiol would be maintained at a high level. C) Progesterone would be maintained at a high level. D) No estradiol would be produced.

D

When you are jogging, your muscles are using more oxygen and releasing more carbon dioxide into the blood than when you are at home on the couch. Which of the following would occur during your jog? A) The concentration of bicarbonate ions (HCO3-) in the blood would decrease. B) The volume of the dead air space would decrease. C) Blood pH would become more basic. D) The medullary respiratory center would detect rising carbon dioxide levels.

D

Consider a mutation that causes concurrent flow through a fish's gills. What would you expect to observe as a result of this mutation? a. The P2 - P1 term in Fick's law would decrease b. The fish would receive less oxygen than a normal fish c. The fish would receive more oxygen than a normal fish d. A and B are correct e. I do not know

D Concurrent flow would cause blood to flow in the same direction as water through the fish's gills. This is much less efficient than countercurrent flow because in concurrent flow the partial pressure of oxygen is highest in both the gills and blood is highest at the start of the system and lowest at the end, causing the P2 - P1 term in Fick's law to decrease. This results in only half of the oxygen in the water diffusing into the blood as the two flows reach equilibrium. Countercurrent flow maintains the greatest differences in the partial pressures of gasses between the gills and the blood, thus allowing more gas exchange between the two streams.

Maternal and fetal hemoglobin oxygen binding affinities differ. Which statement best describes the difference and why it occurs? a. Maternal hemoglobin affinity is less than the affinity of the fetal hemoglobin because the mother's lungs are more developed b. Maternal hemoglobin affinity is greater than the affinity of the fetal hemoglobin because the mother must maintain more body functions and is subject to higher oxygen requirements c. Maternal hemoglobin affinity is less than the affinity of the fetal hemoglobin because the fetus doesn't require as much oxygen as the mother d. Maternal hemoglobin affinity is less than the affinity of the fetal hemoglobin, which ensures that the fetus will have an adequate supply of oxygen through development e. I do not know

D The maternal hemoglobin has a lower affinity than fetal hemoglobin. This makes it more likely that the maternal hemoglobin will release oxygen to the fetal hemoglobin in the placenta, ensuring that the fetus maintains an adequate supply of oxygen throughout development. The mother's blood is able to easily transfer oxygen to the fetus's blood due to this difference in affinity. The opposite situation would result in the death of the fetus.

A common birth defect, called ventricular septal defect, is characterized by an opening in the wall separating the two ventricles of the heart, allowing blood to flow between the two chambers. Which of the following symptoms would you expect to see as a result of this defect? a. Cardiac muscle atrophy b. Lower blood pressure than expected c. Higher oxygen levels in systemic circulation d. Higher oxygen levels in pulmonary circulation e. I do not know

D The ventricles receive blood from the atria and pass it on to arteries. Typically, blood in the right ventricle is filled with oxygen-poor blood heading toward the pulmonary circulation and the left ventricle is filled with oxygen-rich blood heading toward systemic circulation. When the wall between the two ventricles is not closed properly during development, blood in the ventricles is able to mix. Usually this results in blood flowing from left-to-right, causing a higher level of oxygen in the pulmonary circulation as stated in choice d. Ventricular septal defect also causes a decrease in oxygen levels in systemic circulation.

A contraceptive pill that continuously inhibits the release of gonadotropin-releasing hormone (GnRH) from the hypothalamus will _____. A) increase the production of estrogen and progesterone by the ovaries B) stimulate the secretion of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) from the posterior pituitary gland C) initiate ovulation D) increase the flow phase of the menstrual cycle E) reduce the secretion of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) from the anterior pituitary gland

E

A decrease from pH 7.4 to pH 7.2 causes hemoglobin to _____. A) denature B) release all bound carbon dioxide molecules C) decrease its binding of H+ D) bind more oxygen molecules E) give up more of its oxygen molecules

E

At the time of fertilization, the maturation of the human oogonium has resulted in _____. A) four zygotes B) four primary oocytes C) two primary oocytes D) four secondary oocytes E) one secondary oocyte

E

During the menstrual cycle, _____ peaks first, _____ peak next, and finally _____ surges. A) progesterone; luteinizing hormone (LH) and follicle-stimulating hormone (FSH); estradiol B) testosterone; estradiol and follicle-stimulating hormone (FSH); progesterone C) estradiol; luteinizing hormone (LH) and follicle-stimulating hormone (FSH); testosterone D) estradiol; luteinizing hormone (LH) and progesterone; follicle-stimulating hormone (FSH) E) estradiol; luteinizing hormone (LH) and follicle-stimulating hormone (FSH); progesterone

E

Genetic mutations in asexually reproducing organisms lead to more evolutionary change than do genetic mutations in sexually reproducing ones because _____. A) asexually reproducing organisms devote more time and energy to the process of reproduction than do sexually reproducing organisms B) more genetic variation is present in organisms that reproduce asexually than is present in those that reproduce sexually C) asexually reproducing organisms have more dominant genes than organisms that reproduce sexually D) sexually reproducing organisms can produce more offspring in a given time than can asexually reproducing organisms E) asexually reproducing organisms, but not sexually reproducing organisms, pass all mutations on to their offspring

E

Mature human sperm and ova are similar in that they _____. A) are formed before birth B) are produced from puberty until death C) are approximately the same size D) each have a flagellum that provides motility E) both have the same number of chromosomes

E