Bio 2150 Homework Assignments - Exam 3

Which of the events occurs in both spermatogenesis and oogenesis? a. The developing gametes remain connected to one another via cytoplasmic bridges. b. Polar bodies are produced. c. Diploid stem cells divide by mitosis to create a large population of precursor cells. d. Production of gametes begins at puberty. e. Four functional haploid gametes are produced.

Diploid stem cells divide by mitosis to create a large population of precursor cells.

Consider events that occur during the follicular phase of the menstrual cycle. 1. The lining of the uterus thickens. 2. Granulosa cells secrete estradiol. 3. FSH acts on granulosa cells. 4. LH levels surge rapidly, then decline. 5. Ovulation occurs. Select the answer that lists these events in chronological order. a. 3 → 2 → 1 → 4 → 5 b. 1 → 2 → 3 → 4 → 5 c. 2 → 4 → 3 → 1 → 5 d. 4 → 3 → 2 → 1 → 5 e. 3 → 1 → 2 → 4 → 5

a. 3 → 2 → 1 → 4 → 5

Approximately how long after fertilization does the egg implant in the uterine wall? a. 5 days b. 7 days c. 3 days d. 10 days 3. 1 day

a. 5 days

Through which of the answer choices is water gained? a. All of these choices are correct. b. cellular respiration c. osmosis across the gills of freshwater fish d. eating food e. drinking water that has a lower solute concentration than body fluids

a. All of these choices are correct.

What is the advantage for birds and mammals of having a four-chambered heart? a. All of these choices are correct. b. It allows for complete separation of oxygenated and deoxygenated blood. c. It allows for different pressures in the systemic and pulmonary circuits. d. It allows for increased supply of oxygenated blood to active tissues. e. It allows for complete separation of systemic and pulmonary circulation.

a. All of these choices are correct.

Which activity is a function of the endocrine system? a. All of these choices are correct. b. The endocrine system helps synchronize and coordinate body processes. c. The endocrine system regulates development. d. The endocrine system helps an animal respond to the environment. e. The endocrine system regulates growth.

a. All of these choices are correct.

Which of the choices represents a step in gas transport and/or gas exchange? a. All of these choices are correct. b. the transport of O2 in the circulatory system of a frog c. the diffusion of O2 from the lungs of a horse into its bloodstream d. the exhalation of CO2 by a human into his or her environment e. the diffusion of CO2 out of mouse cells into a mouse's bloodstream

a. All of these choices are correct.

Which option is a main function of cartilage? a. All of these choices are correct. b. forming growth plates within bones for rapid growth in adolescence c. forming much of the embryonic vertebrate skeleton d. forming the bone's articular surfaces at a joint

a. All of these choices are correct.

We breathe more quickly and deeply when we exercise. Why does this make sense? Select all that apply. a. Because when we exercise, we produce more CO2 and increased ventilation is necessary to rid ourselves of CO2. b. Because when we exercise, we consume more CO2 and must increase ventilation to supply the CO2. c. 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. d. Because when we exercise, we use more ATP, and additional O2 is necessary to generate sufficient ATP.

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

Which of these events occurs during systole? a. Both ventricles contract. b. The atria fill with blood. c. Both atria contract. d. The ventricles fill with blood. e. The left ventricle contracts.

a. Both ventricles contract.

Which of the statements about open and closed circulatory systems is correct? a. Closed circulatory systems can more effectively control the flow of blood to specific body regions than open circulatory systems. b. Closed circulatory systems have lower resistance to flow than open circulatory systems. c. Closed circulatory systems operate under lower pressure than open circulatory systems. d. Closed circulatory systems deliver materials at slower rates than open circulatory systems. e. Closed circulatory systems use muscular hearts to pump blood through blood vessels, whereas open circulatory systems lack any kind of muscular pump.

a. Closed circulatory systems can more effectively control the flow of blood to specific body regions than open circulatory systems.

How does a vaccination help to prevent a disease? a. It generates a population of memory cells that speed up the response to an actual infection. b. It establishes defenses that prevent a pathogen from entering the body. c. It generates a population of plasma cells that increase the concentration of antibody in the bloodstream. d. It reduces the severity of symptoms to a disease.

a. It generates a population of memory cells that speed up the response to an actual infection.

What is the main benefit of having hemoglobin in the blood? a. It increases the amount of oxygen that can be carried in the blood. b. It keeps oxygen separated from carbon dioxide within the blood. c. It increases the solubility of carbon dioxide in the blood plasma. d. It is an important source of iron for body cells.

a. It increases the amount of oxygen that can be carried in the blood.

Chemoreceptors in the circulatory system detect changes in circulating pCO2. If CO2 concentrations get too high, the rate of ventilation increases. Why does this make sense? a. It makes sense because tissues that are more actively working produce more CO2 and, therefore, need more O2. b. It makes sense because CO2 is formed from O2 and, therefore, CO2 is a sign that oxygen is being consumed. c. Actually, it does not make sense. There is no relationship between CO2 and ventilation rate. d. It makes sense because hemoglobin carries CO2 and, therefore, blocks oxygen binding to the heme site, creating an oxygen deficiency.

a. It makes sense because tissues that are more actively working produce more CO2 and, therefore, need more O2.

Which of the statements describes innate immunity? a. It reacts to a wide variety of pathogens. b. It is a response to a specific pathogen and is the basis for the use of vaccines. c. It is a response to a specific pathogen. d. It is the basis for the use of vaccines.

a. It reacts to a wide variety of pathogens.

Which of the statements about K‑strategists is false? a. K‑strategists reproduce frequently. b. K‑strategists evolved in environments with intense competition for limited food. c. K‑strategists produce few offspring. d. K‑strategists evolved in stable environments. e. K‑strategists invest considerable parental time and care into raising their offspring.

a. K‑strategists reproduce frequently.

A key difference between hormonal regulation of the reproductive systems of human males versus human females is that: a. LH and FSH are released cyclically in females, but nearly continuously in males. b. LH is released continuously in males and FSH is released cyclically in females. c. LH and FSH are released only in males. d. LH and FSH are released only in females. e. LH is released in males and FSH is released in females.

a. LH and FSH are released cyclically in females, but nearly continuously in males.a. LH and FSH are released cyclically in females, but nearly continuously in males.

_____ are chemical signals that, instead of being secreted into the bloodstream, are introduced by animals into their habitats. They can be used to attract mates and mark territories. a. Pheromones b. Growth Factors c. Neurotransmitters d. Hormones

a. Pheromones

_____ are chemical signals that, instead of being secreted into the bloodstream, are introduced by animals into their habitats. They can be used to attract mates and mark territories. a. Pheromones b. Hormones c. Growth factors d. Neurotransmitters

a. Pheromones

Which of the statements about veins is true? a. The blood pressure within the veins is much lower than the blood pressure within the arteries. b. Veins located in the head have one-way valves that help prevent blood from pooling due to gravity. c. Only 20% of the total blood volume resides in the venous circulation at any given time. d. Veins have thicker walls than arteries.

a. The blood pressure within the veins is much lower than the blood pressure within the arteries.

Which of the statements about metabolic rate is false? a. The metabolic rate per gram of tissue is greater in large endotherms than in small endotherms. b. An animal's overall metabolic rate increases with the animal's mass. c. Metabolic rate may be measured by determining the rate of oxygen consumption. d. The metabolic rate per gram of tissue is greater in endotherms than in ectotherms. e. The metabolic rate per gram of tissue in ectotherms is dependent on external temperature.

a. The metabolic rate per gram of tissue is greater in large endotherms than in small endotherms.

Which statements describe fast-twitch muscle fibers? Select all that apply. a. They obtain energy mainly through glycolysis. b. They have a higher ratio of actin to myosin. c. They consume more ATP than slow-twitch fibers but have fewer mitochondria. d. They have less resistance to fatigue than slow-twitch fibers. e. They tend to be smaller in diameter than slow-twitch fibers.

a. They obtain energy mainly through glycolysis. c. They consume more ATP than slow-twitch fibers but have fewer mitochondria. d. They have less resistance to fatigue than slow-twitch fibers.

____, such as thyroid-stimulating hormone (TSH), signal organs of the endocrine system to secrete new, additional hormones. a. Tropic hormones b. Releasing hormones c. Stimulating hormone

a. Tropic hormones

Which of the answer choices does not occur when antidiuretic hormone (ADH) is present? a. Water diffuses into the collecting duct from the interstitial fluid. b. The urine in the collecting duct becomes more concentrated. c. The collecting duct walls become permeable to water. d. All of these answer choices are correct. e. Aquaporins insert in the membrane of the collecting duct cells.

a. Water diffuses into the collecting duct from the interstitial fluid.

The ability to distinguish self from nonself is: a. a feature of both the innate and adaptive immune systems. b. a feature of only the adaptive immune system. c. a feature of only the innate immune system.

a. a feature of both the innate and adaptive immune systems.

Which of the answer choices is not part of the innate immune system? a. a helper T cell b. a cell wall c. skin d. cilia

a. a helper T cell

A taxonomist is examining adult specimens of an owl, a bear, and a bony swordfish. He should find all of these features in adult animals except: a. a notochord. b. a distinct coelom or body cavity. c. bilateral symmetry. d. bony vertebrae. e. a jaw.

a. a notochord.

A new hormone has been isolated from an organism. Although the structure of the hormone has not yet been determined, the hormone is known to exert its effects by forming a hormone-receptor complex that acts as a transcription factor within target cells. What type of hormone is this most likely to be? a. a steroid hormone b. either a steroid or a peptide hormone c. a peptide hormone d. either an amine or a peptide hormone e. either a steroid hormone or an amine hormone

a. a steroid hormone

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

a. a thickness under 10 micrometers b. a large surface area

tropic hormones: a. act on other endocrine organs. b. suppress the immune system. c. suppress the appetite. d. are released from the thyroid gland. e. regulate the metabolic state of the body.

a. act on other endocrine organs.

If a skeletal muscle is no longer able to make enough ATP, then: a. actin and myosin in the sarcomeres will remain bound. b. the muscle will be unable to shorten. c. actin and myosin in the sarcomeres are in the unbound state. d. there will be low levels of acetylcholine at the motor endplate.

a. actin and myosin in the sarcomeres will remain bound.

Which part of the amniotic egg is a fluid-filled sac that allows the embryo to develop in a watery environment? a. amnion b. allantois c. chorion d. shell e. yolk sac

a. amnion

The _____ is stimulated by releasing factors from the _____ that are transported in the bloodstream. a. anterior pituitary gland; hypothalamus b. hypothalamus; posterior pituitary gland c. anterior pituitary gland; posterior pituitary gland d. posterior pituitary gland; anterior pituitary gland e. posterior pituitary gland; hypothalamus

a. anterior pituitary gland; hypothalamus

A new hormone is discovered that appears to play a role in bone development. The hormone is hydrophilic and composed of several amino acids. How should this hormone be classified? a. as a peptide hormone b. as a steroid hormone c. as an amine hormone d. as a pheromone

a. as a peptide hormone

B cells undergo _____, where a specific cell will divide in response to its associated antibody recognizing an antigen. a. clonal selection b. genomic recombination c. positive selection d. autoimmune disease e. inflammation

a. clonal selection

What event results from the hydrolysis of ATP to ADP by the myosin head? a. cocking of myosin head b. shortening of the muscle fiber c. the power stroke d. cross-bridge formation

a. cocking of myosin head

Which of the structures is not matched properly with its function? a. collecting ducts: selective reabsorption of key electrolytes and solutes b. glomerulus: filtration c. bladder: storage and elimination of urine d. ureter: transport of urine to the bladder e. renal tubules: secretion of additional wastes

a. collecting ducts: selective reabsorption of key electrolytes and solutes

Which hormone(s) do ovaries secrete? a. estrogen and progesterone b. progesterone c. testosterone d. estrogen

a. estrogen and progesterone

Refer to the figure shown. In multicellular animals with pressurized circulatory systems, as shown in the figure, the correct order of processes in waste elimination is: a. filtration, reabsorption, secretion. b. reabsorption, secretion, filtration. c. filtration, secretion, reabsorption. d. secretion, reabsorption, filtration. e. secretion, filtration, reabsorption.

a. filtration, reabsorption, secretion.

During which developmental stage or process do cells move to new positions in the developing embryo? a. gastrulation b. fertilization c. blastula d. morula

a. gastrulation

In muscle and liver tissue, glucose consumed in the diet, but not immediately used, is stored as: a. glycogen. b. fatty acids. c. fats. d. ATP.

a. glycogen.

The figure shows a tube with walls that are only permeable to water. The solute concentration of fluid entering the tube is different from that exiting the tube. The concentration of the solution outside the tube is always higher than what is inside the tube for the entire length of the tube. The volume of fluid entering the tube is _____ the volume exiting the tube. a. greater than b. less than c. the same as

a. greater than

Because most herbivores do not produce cellulase, they have specialized compartments in their digestive tracts that: a. house large populations of bacteria that do produce cellulase. b. grind up the plant material using muscular gizzards or other structures. c. ferment nutrients in the hindgut. d. provide appropriate temperature and pH for breaking down plant material. e. secrete alternative enzymes that carry out the same function as cellulase.

a. house large populations of bacteria that do produce cellulase.

Examine the figure. The figure shown illustrates that, as water flows into a region with high solute concentration, it exerts an opposing force called _____ pressure, which eventually prevents additional water from moving into the compartment, bringing the system into equilibrium. a. hydrostatic b. osmotic c. concentration

a. hydrostatic

The partial pressure of one gas in a mixture is: a. its fractional contribution to total pressure of the mixture. b. the weight of a given volume of the gas. c. a measure of how quickly a gas moves across a respiratory surface. d. the difference in concentration of that gas inside and outside of a cell. e. equivalent to the total atmospheric pressure.

a. its fractional contribution to total pressure of the mixture.

a calorie is a: a. measure of energy. b. measure of entropy. c. particular quantity of food. d. measure of the nutritional quality of food.

a. measure of energy.

The gizzard of a bird is important for which of the activities? a. mechanical breakdown of food b. chemical breakdown of proteins c. storage of food d. absorption of nutrients e. chemical breakdown of carbohydrates

a. mechanical breakdown of food

If gastrulation fails to occur, which of the structures does not form? a. mesoderm b. inner cell mass c. blastocyst d. epiblast

a. mesoderm

Chemical elements other than carbon, hydrogen, oxygen, and nitrogen that are required in the diet and must be obtained from the food an animal eats are otherwise known as: a. minerals. b. vitamins. c. non-essential amino acids. d. fats. e. essential amino acids.

a. minerals.

Among the multiple types of teeth, _____ are used predominantly for crushing and grinding. a. molars and premolars b. incisors c. canines d. wisdom teeth

a. molars and premolars

Which of the choices is an example of bulk flow during gas exchange in vertebrates? a. movement of water past a respiratory surface b. movement of carbon dioxide from body cells into the bloodstream c. movement of hemolymph throughout the body d. all of these choices are correct. e. movement of oxygen from the lungs into the bloodstream

a. movement of water past a respiratory surface

Cnidarians are able to capture prey with the aid of _____, harpoon-like organelles that are often tipped with neurotoxins. a. nematocysts b. choanocytes c. mesoglea d. None of the other answer options is correct. e. polyps

a. nematocysts

When proteins and nucleic acids are broken down, the toxic products are collectively called _____ waste. a. nitrogenous b. soluble c. chemical

a. nitrogenous

The immune system usually responds to _____ cells and molecules but not to _____ cells and molecules. a. nonself; self b. self; nonself c. host; self d. host; foreign

a. nonself; self

The key hormone of childbirth is _____, which is released from the posterior pituitary gland. It stimulates uterine contractions which, in turn, stimulate more of the hormone to be released. a. oxytocin b. estrogen c. GnRH d. LH e. FSH

a. oxytocin

The hormone _____, released from the _____, causes uterine contractions that facilitate childbirth. a. oxytocin; posterior pituitary b. progesterone; uterus c. prolactin; anterior pituitary d. estrogen; ovaries e. oxytocin; anterior pituitary

a. oxytocin; posterior pituitary

Linnaeus sorted animals into groups based on body plans. Today, these groupings are called: a. phlya. b. families. c. branches on the phylgenetic tree.

a. phyla

Allergies result when the immune system: a. responds to harmless nonself molecules and cells. b. responds to self molecules and cells. c. responds to harmful nonself molecules and cells. d. does not respond to self molecules and cells.

a. responds to harmless nonself molecules and cells.

Skeletal muscle contraction is largely dependent on calcium ions that exit the: a. sarcoplasmic reticulum. b. extracellular space. c. Z disc. d. extensions of the plasma membrane.

a. sarcoplasmic reticulum.

Which of the choices is the correct path taken by sperm from the site of production to the site of ejection? a. seminiferous tubules, epididymis, vas deferens, ejaculatory duct, urethra b. seminiferous tubules, vas deferens, ejaculatory duct, epididymis, urethra c. epididymis, seminiferous tubules, vas deferens, urethra, ejaculatory duct d. epididymis, seminiferous tubules, vas deferens, ejaculatory duct, urethra e. vas deferens, epididymis, seminiferous tubules, ejaculatory duct, urethra

a. seminiferous tubules, epididymis, vas deferens, ejaculatory duct, urethra

Atrioventricular valves separate: a. the left atrium from the left ventricle and the right atrium from the right ventricle. b. the aorta from the left ventricle. c. the right atrium from the left atrium and the right ventricle from the left ventricle. d. the right and left ventricles.

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

If increased, which options increase muscle force? Select all that apply. a. the number of activated motor units b. increasing the strength of an isomorphic contraction c. the distance between muscle fibers d. motor neuron firing rate

a. the number of activated motor units d. motor neuron firing rate

Essential amino acids must be supplied in the diet because: a. they are necessary for protein biosynthesis, but we do not have the biochemical pathways to synthesize those amino acids. b. only essential amino acids can be oxidized when necessary for ATP synthesis and cellular respiration. c. proteins cannot be synthesized without amino acids and, therefore, all amino acids are essential.

a. they are necessary for protein biosynthesis, but we do not have the biochemical pathways to synthesize those amino acids.

Depending on their environments, animals may lose water: Select all that apply. a. through their gills b. during cellular respiration. c. through their lungs. d. by sweating. e. in urine and feces.

a. through their gills c. through their lungs. d. by sweating. e. in urine and feces.

The primary function of the loop of Henle is: a. to generate a concentration gradient between the inner medulla and outer cortex. b. to concentrate the filtrate passing through the loop. c. to dilute the filtrate passing through the loop. d. selective reabsorption of glucose and other solutes into the bloodstream. e. active secretion of other wastes from the bloodstream.

a. to generate a concentration gradient between the inner medulla and outer cortex.

Calcium is necessary to initiate muscle contraction. Which molecule binds calcium? a. troponin b. myosin c. actin d. tropomyosin

a. troponin

A fertilized egg is called a(n): a. zygote. b. oocyte. c. blastula. d. gamete. e. ootid.

a. zygote.

What percentage of water is reabsorbed by the proximal convoluted tubule by the time the filtrate leaves it? a. 9% b. 75% c. 50% d. 25% e. 10%

b. 75%

The loop of Henle in the nephrons of desert-dwelling kangaroo rats is much longer than the loop of Henle in humans.What is the advantage of this increased length for the kangaroo rat? a. A longer loop of Henle can generate a larger concentration gradient, which allows for the production of a less concentrated urine. b. A longer loop of Henle can generate a larger concentration gradient, which allows for the production of a more concentrated urine. c. A longer loop of Henle can generate a smaller concentration gradient, which allows for the production of a less concentrated urine. d. None of the answer options is correct. e. A longer loop of Henle can generate a smaller concentration gradient, which allows for the production of a more concentrated urine.

b. A longer loop of Henle can generate a larger concentration gradient, which allows for the production of a more concentrated urine.

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

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

The adaptive immune system differs from the innate immune system in: a. that the adaptive immune system has the ability to develop immune responses to novel pathogens. b. All of these choices are correct. c. that the adaptive immune system has memory. d. that the adaptive immune system has the ability to target a specific pathogen.

b. All of these choices are correct.

The amniotic egg is a character unique to which groups of animals and their ancestors? a. reptiles b. All of these choices are correct. c. birds d. mammals

b. All of these choices are correct.

Which of the choices results in increased genetic diversity? a. conjugation in prokaryotes b. All of these choices are correct. c. fusion of unique gametes during fertilization d. recombination of alleles between homologous chromosomes during meiosis e. random sorting of homologous chromosomes into different gametes during meiosis

b. All of these choices are correct.

Which of the statements is false? a. The genetic variation produced by sexual reproduction allows for more rapid evolution. b. Asexual reproduction does not occur in vertebrates. c. Not all of the offspring of sexually reproducing individuals can produce offspring. d. Asexual reproduction requires less energy than sexual reproduction. e. Population growth is more rapid among asexually reproducing organisms than among sexually reproducing organisms.

b. Asexual reproduction does not occur in vertebrates.

Antibodies are formed by which cells of the immune system? a. natural killer cells b. B cells c. phagocytes d. mast cells e. T cells

b. B cells

Why might you expect that organisms that produce amniotic eggs will also have internal fertilization? a. Internal fertilization is only found in more advanced organisms that have amniotic eggs. b. Because some amniotic eggs have a hardened shell, they must be fertilized before the shell is deposited around the egg. c. Because internal fertilization requires more refined behaviors to attract mates, those behaviors only evolved in organisms with internal fertilization. d. In mammals, the amniotic egg eventually evolved into the placenta, so there must be internal fertilization so that the embryo can develop in utero.

b. Because some amniotic eggs have a hardened shell, they must be fertilized before the shell is deposited around the egg.

At which point on the phylogeny shown did the amnion first appear? a. A b. C c. B d. D e. E

b. C

Which of the statements about K‑strategists is false? a. K‑strategists invest considerable parental time and care into raising their offspring. b. K‑strategists reproduce frequently. c. K‑strategists produce few offspring. d. K‑strategists evolved in environments with intense competition for limited food. e. K‑strategists evolved in stable environments.

b. K‑strategists reproduce frequently.

The approach most commonly used to measure metabolic rate is to measure the rate of O2 consumption. Although there are small errors inherent in this method, it is easy and provides a good estimate of metabolic rate.Why is the rate of oxygen consumption an appropriate measure of metabolic rate? a. Metabolic rate is the amount of energy released in anabolic processes, and anabolic processes are all aerobic. b. Metabolic rate is the amount of energy used per unit time. The production of usable energy in the form of ATP depends largely on aerobic respiration. c. Metabolic rate is the amount of energy used per unit time and can be measured by the rate of hydrolysis of ATP to ADP and Pi.

b. Metabolic rate is the amount of energy used per unit time. The production of usable energy in the form of ATP depends largely on aerobic respiration.

What is the difference between negative feedback and positive feedback mechanisms? a. Negative feedback mechanisms stabilize a system at a set point; positive feedback mechanisms change the set point. b. Negative feedback mechanisms return a system to a set point; positive feedback mechanisms amplify a response. c. Negative feedback mechanisms move a system away from a set point; positive feedback mechanisms stabilize a system at a set point.

b. Negative feedback mechanisms return a system to a set point; positive feedback mechanisms amplify a response.

Which of the statements about the process of excretion in complex multicellular animals is true? a. Water and all other molecules are actively transported back into the bloodstream during reabsorption. b. Selective filtration of the blood occurs as blood pressure forces materials into an extracellular space. c. Reabsorption helps to send toxic compounds to the liver so they can be detoxified and turned into usable compounds by the body. d. During the process of reabsorption, additional toxic compounds and excess ions that were not filtered from the blood initially are removed from the organism.

b. Selective filtration of the blood occurs as blood pressure forces materials into an extracellular space.

Which of the statements about spermatogenesis is false? a. Sperm are produced continuously within the seminiferous tubules. b. Sperm are motile as soon as they are produced. c. Spermatogenesis takes about 2-3 months. d. Secondary spermatocytes and spermatids are linked together by cytoplasmic bridges.

b. Sperm are motile as soon as they are produced.

how is synaptic signaling different from paracrine signaling? a. All of these choices are correct. b. Synaptic signaling specifically involves neurotransmitters that are released from neurons. c. Synaptic signaling requires receptors to elicit a response in the target cell. d. Synaptic signaling is longer in duration than paracrine signaling. e. Synaptic signaling acts over a longer distance than paracrine signaling.

b. Synaptic signaling specifically involves neurotransmitters that are released from neurons.

Which of the statements is true? a. The adrenal medulla releases epinephrine and cortisol. b. The adrenal medulla is innervated by the sympathetic nervous system. c. The cells of the adrenal medulla are modified muscle cells. d. Adrenaline released by the adrenal cortex acts as a hormone.

b. The adrenal medulla is innervated by the sympathetic nervous system.

Which of the statements about insect respiration is true? a. Air sacs in many insects hold air for use during the night. b. The insect respiratory system is composed of a series of branching tubes called tracheae. c. After diffusing through the walls of the tracheoles, oxygen is delivered to the body tissues by the circulatory system. d. Air enters the bodies of insects through the mouth.

b. The insect respiratory system is composed of a series of branching tubes called tracheae.

which statement about nervous and endocrine signaling is accurate? a. Neurotransmitters and hormones function only over short distances. b. The nervous system transmits signals between adjacent cells using neurotransmitters, whereas the endocrine system signals with hormones. c. Endocrine signaling lasts for a shorter time period than nerve cell signaling. d. The nervous system and endocrine system are both regulatory systems, but the two systems do not communicate directly with one another.

b. The nervous system transmits signals between adjacent cells using neurotransmitters, whereas the endocrine system signals with hormones.

Referring to the figure shown, the movement of glucose is from the lumen of the duodenum through an interstitial cell, out to the extracellular fluid, and into a capillary. What would happen if the action of the Na+-K+ pumps was reduced? a. The direction of flow of glucose would be reversed. b. The rate of flow of glucose into the interstitial cells would be reduced. c. The rate of flow of glucose into the interstitial cells would be increased. d. Nothing would differ: the movement of glucose would be the same as before the reversal.

b. The rate of flow of glucose into the interstitial cells would be reduced.

Which of the statements about bird respiration is true? a. Oxygen is exchanged between the air, the bloodstream in the lungs, and the air sacs. b. The unidirectional flow of air through a bird's lungs maintains a larger concentration gradient for diffusion than can be obtained through tidal breathing. c. Bird lungs receive fresh air only during inhalation. d. It takes four ventilation cycles for a single breath of air to move through a bird's respiratory system. e. Air flowing through the air channels in the lungs moves in a tidal fashion.

b. The unidirectional flow of air through a bird's lungs maintains a larger concentration gradient for diffusion than can be obtained through tidal breathing.

You are infected with the latest strain of the flu virus. How will your cytotoxic T cells respond? a. They will directly destroy the virus. b. They will destroy infected host cells. c. They will secrete antigens. d. They will secrete antibodies. e. They will destroy all host cells.

b. They will destroy infected host cells.

Which of the choices presents a challenge in gas exchange for fish but not for terrestrial animals? Select all that apply. a. Unidirectional flow of water is less efficient than tidal ventilation. b. Water is more dense and more viscous than air. c. Water contains much less O2 than air per unit volume. d. Diffusion occurs more slowly in water than in air. e. Gills have less surface area than lungs.

b. Water is more dense and more viscous than air. c. Water contains much less O2 than air per unit volume. d. Diffusion occurs more slowly in water than in air.

Which option is the supportive element of hydrostatic skeletons? a. contractile proteins b. a fluid-filled body cavity c. a mineral matrix d. a hard outer covering

b. a fluid-filled body cavity

Which of the answer choices is required to activate a helper T cell, which in turn can stimulate antibody production by B cells? a. an antibody b. an antigen displayed by a major histocompatibility complex protein c. a major histocompatibility complex alone d. an antigen alone e. an antibody displayed by a major histocompatibility complex protein

b. an antigen displayed by a major histocompatibility complex protein

which of these endocrine organs and hormones are paired incorrectly? a. anterior pituitary gland: growth hormone b. anterior pituitary gland: antidiuretic hormone c. posterior pituitary gland: antidiuretic hormone d. posterior pituitary gland: oxytocin e. hypothalamus: releasing factors

b. anterior pituitary gland: antidiuretic hormone

Autoimmune disorders result from T cells that: a. produce alternate T cell receptors (TCRs) while circulating in the bloodstream. b. are activated by major histocompatibility complex (MHC) molecules displaying self antigens. c. fail to recognize MHC proteins on cell membranes. d. fail to produce TCRs.

b. are activated by major histocompatibility complex (MHC) molecules displaying self antigens.

A man is scratched by his cat. A phagocyte near the scratch site recognizes and engulfs a bacterium. Shortly thereafter, more phagocytes arrive in the tissue surrounding the scratch. How are the additional phagocytes recruited to the site of the scratch? a. by antigens secreted by the initial phagocyte b. by cytokines secreted by the initial phagocyte c. by antigens secreted by the bacteria d. by cytokines produced by the bacteria

b. by cytokines secreted by the initial phagocyte

Which of the species is most likely a K-strategist? a. fish b. chimpanzee c. frog d. butterfly

b. chimpanzee

Virus-infected cells are detected and destroyed by which cell-mediated immune response? a. macrophages b. cytotoxic T cells c. B cells d. helper T cells

b. cytotoxic T cells

An individual with vitamin D deficiency will experience: a. nervous system disorders. b. difficulty absorbing sufficient amounts of calcium from their diet. c. slow wound healing. d. anemia. e. bleeding gums and loss of teeth.

b. difficulty absorbing sufficient amounts of calcium from their diet.

Calcium levels in the blood are primarily maintained through the interactions of two different hormones, calcitonin and parathyroid hormone. Based on your understanding of homeostasis through feedback mechanisms, we could also describe the action of these hormones as: a. positive feedback. b. exerting opposite influences on the concentration of blood calcium. c. exerting the same influence on the concentration of blood calcium.

b. exerting opposite influences on the concentration of blood calcium.

Motion that causes two bones to move further apart from each other is known as: a. flexion b. extension. c. rotation. d. lengthening.

b. extension.

Most animals rely on _____, in which food is isolated and broken down in a body compartment rather than inside individual cells. a. neither intra- nor extracellular digestion b. extracellular digestion c. intracellular digestion d. both intra- and extracellular digestion

b. extracellular digestion

Antibody diversity is primarily the result of: a. gene silencing. b. genomic rearrangement. c. differential gene expression. d. mRNA splicing.

b. genomic rearrangement.

Which of the choices correctly describes the path of a drop of blood leaving the human heart? a. heart → arteries → arterioles → capillaries → venules → veins → heart b. heart → arteries → arterioles → capillaries → venules → veins → heart c. heart → arterioles → arteries → capillaries → veins → venules → heart d. heart → venules → veins → capillaries → arteries → arterioles → heart e. heart → arteries → veins → capillaries → arterioles → venules → heart

b. heart → arteries → arterioles → capillaries → venules → veins → heart

Which of these structures serves as a connection between the nervous and endocrine systems? a. thyroid gland b. hypothalamus c. pancreas d. pineal gland e. adrenal gland

b. hypothalamus

Which of these changes would increase the rate of oxygen diffusion from the air into the body cells of a flatworm? a. increasing the surface area of the body and the partial pressure of oxygen inside the cells b. increasing the surface area of the body c. increasing the thickness of the body wall d. All of these choices are correct. e. increasing the partial pressure of oxygen inside of the cells

b. increasing the surface area of the body

If gastrulation fails to occur, which of the structures does not form? a. inner cell mass b. mesoderm c. blastocyst d. epiblast

b. mesoderm

Moving from the lumen outward, what is the correct order of layers that make up the lining of the digestive tract? a. serosa, nerve net, longitudinal muscle layer, circular muscle layer, submucosa, mucosa b. mucosa, submucosa, circular muscle layer, nerve net, longitudinal muscle layer, serosa c. mucosa, circular muscle layer, serosa, nerve net, longitudinal muscle layer, submucosa d. submucosa, mucosa, circular muscle layer, longitudinal muscle layer, nerve net, serosa e. serosa, submucosa, mucosa, longitudinal muscle layer, nerve net, circular muscle layer

b. mucosa, submucosa, circular muscle layer, nerve net, longitudinal muscle layer, serosa

A macrophage destroys a pathogen by: a. production of antigens. b. phagocytosis. c. production of antibodies. d. secretion of histamine.

b. phagocytosis.

Which of the groups of molecules commonly serve as sources of energy for animals? a. proteins and carbohydrates b. proteins, lipids, and carbohydrates c. carbohydrates and lipids d. carbohydrates, nucleic acids, and lipids e. proteins and lipids

b. proteins, lipids, and carbohydrates

Which of these chemicals will not pass through the phospholipid bilayer of a membrane? a. molecular oxygen b. sodium ions c. carbon dioxide

b. sodium ions

Which layer of cells in the human blastocyst migrates inwards during gastrulation to form all three developmental tissue layers? a. the hypoblast b. the epiblast c. the inner cell mass

b. the epiblast

What is the function of the bicarbonate ions secreted by the pancreas? a. to stimulate secretion of the hormone secretin b. to neutralize acid produced by the stomach c. to stimulate the release of bile from the gall bladder d. All of these choices are correct. e. to facilitate the transport of nutrients across the intestinal wall

b. to neutralize acid produced by the stomach

Gastrulation results in the formation of a: a. bilaminar gastrula consisting of the epiblast and the hypoblast. b. trilaminar embryo consisting of ectoderm, endoderm, and mesoderm. c. bilaminar embryo consisting of the epiblast and the hypoblast. d. trilaminar embryo consisting of the epiblast, the mesoblast, and the hypoblast. e. gastrula consisting of a trilaminar embryo.

b. trilaminar embryo consisting of ectoderm, endoderm, and mesoderm.

The specific part of an antibody to which an antigen binds is called the: a. heavy chain. b. variable region. c. MHC class II. d. light chain. e. MHC class I.

b. variable region.

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

c. 4

Approximately how often is the blood filtered by the human kidney? a. 144 times a day (once every 10 minutes) b. 12 times a day (once every 2 hours) c. 60 times a day (once every 24 minutes) d. once a day (once every 24 hours)

c. 60 times a day (once every 24 minutes)

Basic life processes account for what percentage of energy use in animals? a. 25 percent b. 50 percent c. 70 percent d. 10 percent

c. 70 percent

Imagine a planet that has a similar atmospheric pressure to Earth (760 mmHg) but different concentrations of gases in its atmosphere. On this hypothetical planet, oxygen makes up 10% of the atmosphere, carbon dioxide makes up 15%, and nitrogen makes up the remaining 75%. Based on this information, what is the partial pressure of oxygen on this new planet? a. 160 mmHg b. 571 mmHg c. 76 mmHg d. 114 mmHg e. 646 mmHg

c. 76 mmHg

Which of the statements about excretory organs in complex multicellular animals is false? a. If organisms relied on molecule-specific active transport of wastes alone, then novel toxic compounds could not be excreted. b. Excretory systems are important for balancing both electrolyte and water levels in the body. c. All of the materials that are removed from the blood during filtration will eventually be excreted. d. The process of excretion has more steps in complex multicellular animals with pressurized circulatory systems than in simple multicellular animals.

c. All of the materials that are removed from the blood during filtration will eventually be excreted.

The binding of a phagocyte's toll-like receptor (TLR) to a foreign cell (for example, a bacterium): a. leads to the recruitment of other immune cells. b. acts as a trigger for the phagocytic cell to engulf the bacterium c. All of these choices are correct. d. is a signal for the phagocytic cell to release cytokines to recruit other immune cells.

c. All of these choices are correct.

What can animals do to maintain an energy balance when food supplies become scarce in winter? a. hibernate to reduce energy expenditure and conserve energy reserves b. migrate to areas with more abundant food supplies c. All of these choices are correct. d. build up enough of a positive energy balance during summer and fall to sustain them through the winter e. migrate to warmer areas

c. All of these choices are correct.

Which chemical or enzyme is secreted by the stomach when an organism is eating? a. hydrochloric acid (HCI) b. gastrin c. All of these choices are correct. d. pepsin

c. All of these choices are correct.

Which of the answer choices is an advantage of producing very concentrated urine? a. reducing the need to drink b. ability to live in drier environments c. All of these choices are correct. d. minimizing water loss

c. All of these choices are correct.

Which type of cell produces antibodies? a. helper T cells b. cytotoxic T cells c. B cells d. natural killer cells e. mast cells

c. B cells

T cells must undergo both positive and negative selection during development. This means that they must: a. not recognize or bind to self antigens associated with MHC molecules. b. Both of these choices are correct. c. recognize and bind to self MHC (major histocompatibility complex) molecules.

c. Both of these choices are correct.

The membranous sac enclosing the glomerulus of a mammalian kidney is called: a. the medulla. b. the renal pelvis. c. Bowman's capsule. d. the renal pyramid. e. the nephron.

c. Bowman's capsule.

If an individual carries a mutation that results in a complete lack of major histocompatibility complex (MHC) class I proteins, how would the individual's immune response be affected? a. Helper T cells would not be able to interact with antigen-presenting cells. b. Plasma cell antibodies would not be able to attach to antigens. c. Cytotoxic T cells would not be able to target (and destroy) infected cells. d. Memory cell antibodies would not be able to attach to antigens.

c. Cytotoxic T cells would not be able to target (and destroy) infected cells.

How is a fetus able to extract O2 from its mother's blood? a. The maternal blood mixes with the fetal blood in the placenta to provide O2. b. Fetal hemoglobin has a lower affinity for O2 than maternal hemoglobin. c. Fetal hemoglobin has a higher affinity for O2 than maternal hemoglobin. d. The pO2 of fetal blood is higher than the pO2 of maternal blood. e. Fetal blood has a higher concentration of hemoglobin than maternal blood.

c. Fetal hemoglobin has a higher affinity for O2 than maternal hemoglobin.

Which of the statements is true? a. The systemic blood pressure of a bird is lower than that of a fish. b. The walls of the human right ventricle are thicker than the walls of the left ventricle. c. Human blood pressure in the pulmonary circulation is lower than blood pressure in the systemic circulation. d. The human left ventricle pumps deoxygenated blood, whereas the right ventricle pumps oxygenated blood.

c. Human blood pressure in the pulmonary circulation is lower than blood pressure in the systemic circulation.

Mammals and birds have four-chambered hearts and fully divided pulmonary and systemic circulations. The circulatory systems of reptiles and amphibians are sometimes presented as "inferior" because pulmonary and systemic circulations are not completely separate. What might be an advantage to incompletely separated circuits in these organisms? a. Incompletely separated circuits allow for higher blood pressure and therefore increased blood flow. b. Incompletely separated circuits take less energy to function. c. In incompletely separated circuits, the distribution of blood flow can be adjusted, depending on whether or not the animal is breathing air through its lungs.

c. In incompletely separated circuits, the distribution of blood flow can be adjusted, depending on whether or not the animal is breathing air through its lungs.

Which of the statements about the proximal convoluted tubule of the mammalian kidney is accurate? a. It has thin walls permeable to only water. b. It is impermeable to water. c. It reabsorbs glucose and amino acids filtered by the glomerulus. d. It is the second section of the renal tubule that filtrate encounters after passing into Bowman's space.

c. It reabsorbs glucose and amino acids filtered by the glomerulus.

why are some body cells responsive to a particular hormone, whereas others are not? a. Responsive cells have complex signal transduction pathways, whereas cells that do not respond to a particular hormone lack these pathways. b. Whether or not a cell responds to a hormone depends entirely on what type of cell it is (liver cell vs. fat cell vs. nerve cell), because hormones only activate one type of cell. c. Responsive cells express a receptor specific for the hormone. d. Responsive cells are located closer to the gland that releases the hormone.

c. Responsive cells express a receptor specific for the hormone.

Why is it useful for T cells that do not recognize self MHC (major histocompatibility complex) molecules to be removed from the maturing T cell population? a. T cells unable to recognize self MHC molecules cannot be stimulated by cytokines released in areas of infection. b. T cells unable to recognize self MHC molecules will bind and potentially attack, and kill, all the cells of the body. c. T cells unable to recognize self MHC molecules will be unable to bind to cells that present foreign antigens on MHC class I proteins.

c. T cells unable to recognize self MHC molecules will be unable to bind to cells that present foreign antigens on MHC class I proteins.

Which of the statements about mammalian cleavage is false? a. Zygotic transcription begins as early as the two-cell stage. b. Cell divisions extend completely through the egg. c. The embryo increases in overall size during cleavage. d. Early divisions do not occur at the same time. e. Cleavage in mammals occurs more slowly than cleavage in other organisms.

c. The embryo increases in overall size during cleavage.

At any given point along the length of the gill lamella, how does the pO2 of the blood flowing through the blood vessels in the lamella compare to the pO2 of the water flowing over the gill lamella? a. The pO2 of the blood is variable and cannot be compared to the pO2 of the water. b. The pO2 of the blood is higher than the pO2 of the water. c. The pO2 of the blood is lower than the pO2 of the water. d. The pO2 in the blood is equal to the pO2 of the water. e. The pO2 of the blood never exceeds 50% of the pO2 of the water.

c. The pO2 of the blood is lower than the pO2 of the water.

Why are muscles always associated with some type of skeleton? a. The skeleton is necessary for animals to grow. b. All of these choices are correct. c. The skeleton transmits the force generated by the muscles. d. The skeleton provides a storage area for calcium ions used by muscle. e. The skeleton is always necessary to support the body against gravity.

c. The skeleton transmits the force generated by the muscles.

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

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

The ability to distinguish self from nonself is: a. a feature of only the adaptive immune system. b. a feature of only the innate immune system. c. a feature of both the innate and adaptive immune systems.

c. a feature of both the innate and adaptive immune systems.

All echinoderms have: a. a cardiovascular circulatory system and five-fold symmetry. b. a cardiovascular circulatory system and bilateral symmetry. c. a water vascular system and five-fold symmetry.

c. a water vascular system and five-fold symmetry.

List the three major forms of nitrogenous waste in order from highest amount of water required for excretion to lowest amount of water required for excretion. a. uric acid, urea, ammonia b. urea, uric acid, ammonia c. ammonia, urea, uric acid d. ammonia, uric acid, urea e. urea, ammonia, uric acid

c. ammonia, urea, uric acid

Which of the factors affects the rate of diffusion of a substance? a. viscosity b. direct supply of metabolic energy (ATP) c. concentration gradient d. presence of other solutes

c. concentration gradient

Aside from whatever digestion has happened before the food reaches the small intestine, the bulk of digestion takes place in the: a. appendix. b. colon. c. duodenum. d. ileum. e. jejunum.

c. duodenum.

Most individuals who include meat in their diet do not need to carefully monitor the protein that they eat. However, vegetarians must monitor their diet more closely to ensure that they are getting appropriate levels of: a. carbohydrates. b. fats. c. essential amino acids. d. vitamins.

c. essential amino acids.

In which of the structures does fertilization typically take place? a. uterus b. ovaries c. fallopian tubes d. cervix e. vagina

c. fallopian tubes

In humans, fertilization usually occurs in the: a. uterus. b. vagina. c. fallopian tubes. d. ovaries. e. cervix.

c. fallopian tubes.

Which of the answer choices correctly describes the path of excretory fluids through a mammalian nephron? a. glomerulus, Bowman's space, proximal convoluted tubule, distal convoluted tubule, loop of Henle, collecting duct b. Bowman's space, glomerulus, proximal convoluted tubule, distal convoluted tubule, loop of Henle, collecting duct c. glomerulus, Bowman's space, proximal convoluted tubule, loop of Henle, distal convoluted tubule, collecting duct d. collecting duct, proximal convoluted tubule, loop of Henle, distal convoluted tubule, Bowman's space, glomerulus e. glomerulus, Bowman's space, loop of Henle, proximal convoluted tubule, distal convoluted tubule, collecting duct

c. 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? a. midgut b. foregut c. hindgut d. crop

c. hindgut

An autoimmune disease occurs when: a. there is an unregulated release of cytokine by helper T cells. b. macrophages engulf normal host cells. c. immune cells react to antigens normally present on host cells. d. cytotoxic T cells attack B cells.

c. immune cells react to antigens normally present on host cells.

The majority of all known animal species are: a. cnidarians. b. vertebrates. c. insects. d. mollusks.

c. insects.

Which of the choices describes the correct path of air through the human respiratory system? a. trachea, bronchi, larynx, bronchioles, alveoli b. trachea, larynx, bronchi, bronchioles, alveoli c. larynx, trachea, bronchi, bronchioles, alveoli d. bronchi, trachea, larynx, bronchioles, alveoli e. larynx, bronchioles, trachea, bronchi, alveoli

c. larynx, trachea, bronchi, bronchioles, alveoli

If you've ever read any stories about Sherlock Holmes, you may remember that he once solved a mystery in which a man died due to injuries sustained from a lion's mane jellyfish. According to the story, the victim encountered this free-floating jellyfish in a pool of water, was stung, and died suddenly. From this information, you can deduce that the victim encountered what form of the jellyfish? a. anemone b. polyp c. medusa d. trochophore c. placozoan

c. medusa

Which of these animals has the highest resting metabolic rate per gram of body tissue? a. polar bear b. cheetah c. mouse d. elephant e. dog

c. mouse

What does the process of extravasation involve? a. release of chemical signals such as histamines or cytokines b. the engulfing of a pathogen by a phagocyte c. movement of phagocytes from the bloodstream into infected tissue d. coating of a pathogen with C-reactive protein

c. movement of phagocytes from the bloodstream into infected tissue

Immunodeficiency is a general term that refers to the loss of: a. immune system function because of genetic mutations. b. immune system function with age. c. one or more components of the immune system. d. functional mast cells in the body.

c. one or more components of the immune system.

Growth factors are examples of which type of chemical signal? a. autocrine signals b. hormones c. paracrine signals d. pheromones e. neurotransmitters

c. paracrine signals

Once the plasma membranes of the egg and sperm fuse, the egg completes meiosis II and undergoes a series of changes that further prevent _____, or fertilization by more than one sperm. a. gastrulation b. cleavage c. polyspermy d. aneuploidy e. polyploidy

c. polyspermy

Nitrogenous wastes are produced through the breakdown of: a. lipids. b. glucose. c. proteins. d. carbohydrates.

c. proteins.

In which of the heart chambers would deoxygenated blood be found? a. right atrium and left ventricle b. left atrium and right ventricle c. right atrium and right ventricle d. right atrium and left atrium e. left atrium and left ventricle

c. right atrium and right ventricle

When stimulated by _____, arterioles supplying the digestive system ______, which decreases blood flow to digestive organs. a. parasympathetic nerves; constrict b. sympathetic nerves; dilate c. sympathetic nerves; constrict d. ADH; constrict e. parasympathetic nerves; dilate

c. sympathetic nerves; constrict

What is the function of a toll-like receptor? a. to bind to cytokines b. to facilitate the release of histamine c. to bind to surface molecules present on pathogens d. to bind to self molecules

c. to bind to surface molecules present on pathogens

Most mammals excrete _____; most aquatic animals excrete _____; birds, insects, and many reptiles excrete _____. a. uric acid; urea; ammonia b. uric acid; ammonia; urea c. urea; ammonia; uric acid d. urea; uric acid; ammonia e. ammonia; urea; uric acid

c. urea; ammonia; uric acid

An animal's metabolic rate can be affected by its: a. body size. b. activity level. c. body temperature. d. All of these choices are correct.

d. All of these choices are correct.

Endotherms: a. include mammals and birds. b. generate heat from the breakdown of food and other metabolic reactions. c. usually maintain a constant body temperature that is higher than that of their environment. d. All of these choices are correct. e. have high metabolic rates.

d. All of these choices are correct.

How can a pathogen be destroyed once a phagocyte internalizes it? a. by degradation by lysosomes b. by containing the cell or particle in a vesicle c. by exposure to reactive oxygen species d. All of these choices are correct.

d. All of these choices are correct.

Which of the statements about oogenesis is true? a. It can take as long as 50 years for some primary oocytes to complete oogenesis. b. Fertilization occurs before the final round of meiotic divisions in humans. c. Primary oocytes form when a female is a fetus in her mother's uterus. d. All of these choices are correct. e. Meiotic divisions are asymmetrical in oogenesis.

d. All of these choices are correct.

Which of the statements is false? a. Animals that use suspension filter feeding are found in both marine and freshwater environments. b. The largest baleen whales are suspension filter feeders. c. The similar feeding strategies of scallops and whales are an example of convergent evolution. d. Animals that use suspension filter feeding are all herbivores.

d. Animals that use suspension filter feeding are all herbivores.

receptors for _____ hormones are located on the plasma membrane and affect target cells by _____ a. peptide; forming hormone-receptor complexes that activate or inhibit gene expression b. amine; forming hormone-receptor complexes that activate or inhibit gene expression c. steroid; forming hormone-receptor complexes that activate or inhibit gene expression d. amine; activating protein kinase enzymes e. steroid; activating protein kinase enzymes

d. amine; activating protein kinase enzymes

the _____ is stimulated by releasing factors from the _____ that are transported in the bloodstream. a. hypothalamus; posterior pituitary gland b. anterior pituitary gland; posterior pituitary gland c. posterior pituitary gland; hypothalamus d. anterior pituitary gland; hypothalamus e. posterior pituitary gland; anterior pituitary gland

d. anterior pituitary gland; hypothalamus

Most proteins consumed in the diet: a. are digested into nucleic acids and absorbed, and may be fed into cellular respiration pathways. b. are absorbed and maintained as functional proteins if the body needs that particular protein. c. are digested into amino acids and then enter into cellular respiration pathways to be reduced so that they provide energy to the organism. d. are broken down into amino acids and absorbed, and may be re-polymerized into the proteins the body needs.

d. are broken down into amino acids and absorbed, and may be re-polymerized into the proteins the body needs.

Consider the image. A Protostomia is distinguished by a(n): a. mesoderm that becomes an anus. b. endoderm that becomes a mouth. c. blastopore that becomes an anus. d. blastopore that becomes a mouth.

d. blastopore that becomes a mouth.

Which of the types of blood vessels would have the greatest resistance to flow? a. arteries b. veins c. arterioles d. capillaries e. venules

d. capillaries

The myriapods include the _____, which are fast-moving predators with front legs modified into venomous fanglike organs, and _____, which are slow-moving herbivores. a. scorpions; millipedes b. millipedes; centipedes c. spiders; mites d. centipedes; millipedes e. centipedes; mites

d. centipedes; millipedes

A newly developed drug works by blocking thyroid hormone receptors throughout the body. Which result would be expected to occur in a patient taking this drug? a. decreased resorption of bone b. increased uptake of glucose by body cells c. production of more dilute urine d. changes in metabolism e. inability to release cortisol

d. changes in metabolism

Antidiuretic hormone (ADH) controls how diluted or concentrated urine is by controlling the permeability of the: a. collecting ducts to electrolytes. b. loops of Henle to electrolytes. c. loops of Henle to water. d. collecting ducts to water. e. collecting ducts to urea.

d. collecting ducts to water.

Endotherms usually, though not always, maintain a _____ body temperature that is _____ that of the environment. a. constant; lower than b. fluctuating; identical to c. constant; identical to d. constant; higher than e. fluctuating; higher than

d. constant; higher than

Refer to the figure shown. In multicellular animals with pressurized circulatory systems, as shown in the figure, the correct order of processes in waste elimination is: a. secretion, filtration, reabsorption. b. filtration, secretion, reabsorption. c. secretion, reabsorption, filtration. d. filtration, reabsorption, secretion. e. reabsorption, secretion, filtration.

d. filtration, reabsorption, secretion.

In which animals does blood flow directly from respiratory organs to tissues without first returning to the heart? a. amphibians b. mammals c. birds d. fish e. reptiles

d. fish

Animals that use suspension filter feeding capture food particles that are: a. buried within the sediments. b. All of these choices are correct. c. laying on the surface of the sea floor. d. floating in the water around them. e. attached to rocks or other hard surfaces.

d. floating in the water around them.

In what order are internal fuel reserves consumed during starvation? a. fat, glycogen, protein b. protein, fat, glycogen c. fat, protein, glycogen d. glycogen, fat, protein e. glycogen, protein, fat

d. glycogen, fat, protein

Which of the hormones is indicative of the presence of a developing embryo and is thus the basis of home pregnancy tests? a. progesterone b. estradiol c. LH d. hCG e. FSH

d. hCG

Which of the choices is not a correct pairing of tooth type and function? a. premolars: shearing b. molars: grinding c. canines: ripping and tearing d. incisors: piercing

d. incisors: piercing

The blood of some individuals does not carry sufficient oxygen to their tissues. These individuals could be deficient in: a. calcium. b. potassium. c. magnesium. d. iron. e. phosphorus.

d. iron.

At the venous end of a capillary, the blood pressure is _____ the osmotic pressure and fluid _____ the blood vessel. a. lower than; moves out of b. higher than; moves out of c. equal to; remains within d. lower than; moves into e. higher than; moves into

d. lower than; moves into

Food poisoning can sometimes result from ingestion of the bacteria Salmonella in meats and eggs. When Salmonella is ingested, it multiplies in the lumen of the gut, where it can lead to inflammation of the gut lining and symptoms like diarrhea and abdominal cramps. Occasionally, the bacteria enter the bloodstream.The route the bacteria take to get to the bloodstream is: a. serosa, outer longitudinal muscle layer, inner circular muscle layer, submucosa, mucosa, lumen. b. lumen, mucosa. c. lumen, mucosa, submucosa, serosa. d. lumen, mucosa, submucosa. e. lumen, mucosa, submucosa, inner circular muscle layer, outer longitudinal muscle layer, serosa.

d. lumen, mucosa, submucosa.

Which cell type is responsible for the strength of the secondary immune response? a. naive B cells b. All of these choices are correct. c. plasma cells d. memory cells

d. memory cells

Which cell type is responsible for the strength of the secondary immune response? a. plasma cells b. All of these choices are correct. c. naive B cells d. memory cells

d. memory cells

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: a. of high CO2 concentration in the tissues, created as a by-product of cellular respiration. b. osmotic pressure causes a net flow of O2 from the tissues into the blood. c. O2 is pumped into the tissues where it is needed. d. of a concentration gradient between O2 in the tissues and O2 in the blood.

d. of a concentration gradient between O2 in the tissues and O2 in the blood.

The pulmonary veins carry: a. deoxygenated blood from the lungs to the left atrium. b. deoxygenated blood from the lungs to the right atrium. c. oxygenated blood from the lungs to the right atrium. d. oxygenated blood from the lungs to the left atrium. e. deoxygenated blood from the heart to the lungs.

d. oxygenated blood from the lungs to the left atrium.

In which of the forms of reproduction does an unfertilized egg develop into a new individual? a. binary fission b. budding c. conjugation d. parthenogenesis e. fragmentation

d. parthenogenesis

After clonal selection, B cells become either _____ cells that secrete _____, or _____ cells with membrane-bound antibodies a. memory; antibodies; plasma b. memory; antigens; plasma c. plasma; antigens; memory d. plasma; antibodies; memory

d. plasma; antibodies; memory

Which of the macromolecules are broken down by pepsin? a. carbohydrates b. nucleic acids c. All of these choices are correct. d. proteins e. lipids

d. proteins

In which of the structures are sperm produced? a. epididymis b. seminal vesicles c. prostate gland d. seminiferous tubules e. vas deferens

d. seminiferous tubules

Osmoregulation is defined as: a. the movement of water from an area of lower solute concentration to an area of higher solute concentration. b. the movement of water through aquaporins. c. the difference in solute concentration on the two sides of a selectively permeable membrane. d. the control of osmotic pressure through regulation of water and solute levels. e. the regulation of membrane permeability.

d. the control of osmotic pressure through regulation of water and solute levels.

The main solute in the filtrate as it enters the distal convoluted tubule is: a. nucleotides. b. electrolytes. c. glucose. d. urea. e. amino acids.

d. urea.

Mammals are divided into three major groups based on: a. ability to produce milk. b. presence of hair. c. presence or absence of a pouch. d. where early development of the young occurs.

d. where early development of the young occurs.

Which of the statements are true regarding histamine? a. It contributes to inflammation. b. It changes the permeability of blood vessels. c. It causes blood vessels to dilate. d. It can be produced by mast cells. e. All of these choices are correct.

e. All of these choices are correct.

Which of the statements is true regarding CO2 in the mammalian bloodstream? a. All CO2 is transported through the mammalian bloodstream as a dissolved gas and is carried directly in the plasma. b. Like oxygen, CO2 is transported through the mammalian bloodstream via hemoglobin; however, CO2 binds to hemoglobin at amine groups rather than heme groups. c. In the mammalian bloodstream, CO2 is much less soluble than O2. d. Unlike oxygen, CO2 is transported through the mammalian bloodstream by myoglobin. e. CO2 is mainly transported through the mammalian bloodstream in the form of bicarbonate ions or carbonic acid.

e. CO2 is mainly transported through the mammalian bloodstream in the form of bicarbonate ions or carbonic acid.

Which of the statements is true? a. Uric acid can be stored at a higher concentration in tissues than urea. b. Ammonia is safe to cells at high concentrations. c. Excretion of urea requires less water than excretion of uric acid. d. Urea is produced and eliminated in the kidneys. e. Excretion of ammonia requires high volumes of water.

e. Excretion of ammonia requires high volumes of water.

_____ are cells of the adaptive immune system that can activate B cells by binding to major histocompatibility complex (MHC) class II protein-antigen complexes. a. Phagocytes b. Plasma B cells c. Cytotoxic T cells d. Memory B cells e. Helper T cells

e. Helper T cells

As you move from sitting in class to riding your bike, what happens to your metabolic rate and levels of oxygen consumption? a. Oxygen consumption increases and metabolic rate decreases. b. Oxygen consumption and metabolic rate remain constant. c. Oxygen consumption and metabolic rate both decrease. d. Oxygen consumption decreases and metabolic rate increases. e. Oxygen consumption and metabolic rate both increase.

e. Oxygen consumption and metabolic rate both increase.

If solution X has a 2% concentration of salt (NaCl) and solution Y has an 8% concentration of NaCl, which of the statements is correct? a. Solution X has a higher osmotic pressure than solution Y. b. Solution X has a higher solute concentration than solution Y. c. Solution X has a lower concentration of water than solution Y. d. Solution X is hypertonic relative to solution Y. e. Solution X is hypotonic relative to solution Y.

e. Solution X is hypotonic relative to solution Y.

The same hormone stimulates gene expression in one cell, but inhibits gene expression in another cell. What is the best explanation for this difference? a. The two cells receive different amounts of the hormone. b. The two cells receive the hormone at different times. c. The hormone can diffuse through the plasma membrane of one cell, but not the other cell. d. The hormone is degraded more quickly in one cell than the other. e. The two cells have different types of receptors for the hormone.

e. The two cells have different types of receptors for the hormone.

As a person ages, his or her thymus shrinks. How does this change affect the effectiveness of vaccinations? a. Vaccinations will have no effect because the entire immune system shuts down when the thymus shrinks to a certain size. b. Vaccinations will be as effective in aging patients as in young patients because T cell development occurs in the bone marrow. c. Vaccinations will be more effective because at birth your thymus made all the T cells you'll need for your entire life. d. Vaccinations will be less effective because B cells will not produce appropriate amounts of antibodies. e. Vaccinations will be less effective because the rate of T cell maturation will be reduced.

e. Vaccinations will be less effective because the rate of T cell maturation will be reduced.

You are a doctor examining a patient's blood test reports. You are looking at the ratio of helper T cells to cytotoxic T cells. Helper T cells _____; cytotoxic T cells _____. You can tell them apart by the type of protein they _____. a. kill altered host cells; activate other immune system cells; secrete b. kill altered host cells; activate other immune system cells; express on their plasma membrane c. activate other immune system cells; kill altered host cells; secrete d. activate antigens; destroy antigens; digest e. activate other immune system cells; kill altered host cells; express on their plasma membrane

e. activate other immune system cells; kill altered host cells; express on their plasma membrane

Which of these hormones increases blood pressure by directly stimulating the distal convoluted tubule and collecting ducts to take up more water and salts? a. antidiuretic hormone b. angiotensin I c. renin d. angiotensin II e. aldosterone

e. aldosterone

Antidiuretic hormone (ADH) controls how diluted or concentrated urine is by controlling the permeability of the: a. collecting ducts to urea. b. collecting ducts to electrolytes. c. loops of Henle to electrolytes. d. loops of Henle to water. e. collecting ducts to water.

e. collecting ducts to water.

Which of the hormones is indicative of the presence of a developing embryo and is thus the basis of home pregnancy tests? a. FSH b. LH c. estradiol d. progesterone e. hCG

e. hCG

In mammals such as humans, the chorion and allantois fuse to form the _____, an organ that allows the embryo to obtain nutrients directly from the mother. a. amnion b. shell c. yolk d. embryo e. placenta

e. placenta

In organisms, the ability to control osmosis depends on the properties of the plasma membranes of individual cells. Based on their ability to permit the free movement of water and some solutes, these membranes are described as: a. diffusible. b. impermeable. c. impervious. d. permeable. e. selectively permeable.

e. selectively permeable.

Which layer of the digestive tract covers and protects the gut? a. longitudinal muscles b. mucosa c. submucosa d. lumen e. serosa

e. serosa

The heartbeat originates in the: a. atrioventricular node located in the wall of the atrioventricular valve. b. atrioventricular node located in the tissue separating the atria and ventricles. c. sinoatrial node located at the junction of the vena cava and the left atrium. d. sinoatrial node and atrioventricular node simultaneously. e. sinoatrial node located at the junction of the vena cava and the right atrium.

e. sinoatrial node located at the junction of the vena cava and the right atrium.

Most nutrient absorption takes place in the: a. liver. b. stomach. c. pancreas. d. large intestine. e. small intestine.

e. small intestine.

in vertebrates, which structure frequently serves as the first intermediary between the areas of the brain that perceive sensory stimuli and the rest of the endocrine system? a. the thyroid gland b. the posterior pituitary gland c. the adrenal glands d. the anterior pituitary gland e. the hypothalamus

e. the hypothalamus

The human embryo normally implants and develops in which of the structures? a. fallopian tubes b. ovaries c. vagina d. cervix e. uterus

e. uterus

Rabbits produce two types of droppings: fecal pellets, which are waste products of digestion, and cecotropes, which they re-ingest. Ruminants do not re-ingest any droppings.Why is re-ingestion required in rabbits but not in ruminants? a. Rabbits use microorganisms in their hindgut to digest cellulose; ruminants secrete cellulose-digesting enzymes into their stomachs. b. Ruminants use microorganisms to digest cellulose and release cellular contents into the stomach to be digested; rabbits secrete cellulose-digesting enzymes into their hindgut so products of digestion can be absorbed. c. Rabbits are hindgut fermenters and consume a carnivorous diet; ruminants are foregut fermenters and have a cellulose-based diet. The digestive systems of rabbits and ruminants are adaptations to these two dietary specializations. d. Rabbits are hindgut fermenters; therefore, nutrients would be lost if the products of fermentation in the cecum were not eaten. Ruminants are foregut fermenters, and the products of digestion are absorbed in the small intestine.

d. Rabbits are hindgut fermenters; therefore, nutrients would be lost if the products of fermentation in the cecum were not eaten. Ruminants are foregut fermenters, and the products of digestion are absorbed in the small intestine.

What effect does the nervous system have on the heart rate? a. The nervous system does not directly affect the heart rate. b. Stimulation by sympathetic nerves causes the pacemaker cells of the AV node to depolarize more rapidly than the pacemaker cells of the SA node. c. Stimulation by sympathetic nerves sets the resting heart rate of the pacemaker cells in the SA node. d. Stimulation by parasympathetic nerves causes the heart rate to slow down. e. Stimulation by either the sympathetic or parasympathetic nerves causes pacemaker cells in the SA node to depolarize more slowly.

d. Stimulation by parasympathetic nerves causes the heart rate to slow down.

You are a doctor and have a patient who has been injured by a rusty nail. As a precaution, you vaccinate her against tetanus. In response to the vaccine, how does her body produce antibodies against C. tetani and prevent future illness due to tetanus? a. Every B cell in her body produces antibodies against C. tetani. b. Every cell in her immune system produces antibodies against C. tetani. c. The B cell that produces the appropriate antibody undergoes genomic rearrangement in order to produce other cells that produce the same antibody. d. The B cell with the appropriate antibody is stimulated to divide, producing plasma cells that make antibodies to C. tetani, and memory cells that "remember" C. tetani.

d. The B cell with the appropriate antibody is stimulated to divide, producing plasma cells that make antibodies to C. tetani, and memory cells that "remember" C. tetani.

Omnivorous, carnivorous, and herbivorous mammals all possess the same four tooth types. How are these distinctions in diet possible between the three types of mammals if they all have the same types of teeth? a. The presence of gaps in the jaw, where no teeth occur, is more important for diet than the different tooth types. b. The animals have different patterns of chewing that enable each dietary specialist to eat specific types of food. c. The different tooth types have little to do with diet; what the different organisms eat is a matter of choice. d. The different tooth types are further specialized in each dietary specialist to maximize the ability to process food.

d. The different tooth types are further specialized in each dietary specialist to maximize the ability to process food.

At any given point along the length of the gill lamella, how does the pO2 of the blood flowing through the blood vessels in the lamella compare to the pO2 of the water flowing over the gill lamella? a. The pO2 of the blood is variable and cannot be compared to the pO2 of the water. b. The pO2 of the blood never exceeds 50% of the pO2 of the water. c. The pO2 of the blood is higher than the pO2 of the water. d. The pO2 of the blood is lower than the pO2 of the water. e. The pO2 in the blood is equal to the pO2 of the water.

d. The pO2 of the blood is lower than the pO2 of the water.

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 statements is correct? a. There will be a net diffusion of oxygen from inside the cell to outside the cell. b. There will be a net diffusion of carbon dioxide out of the cell. c. There will be a net diffusion of carbon dioxide into the cell. d. There will be a net diffusion of oxygen from outside the cell to inside the cell. e. There will be a net diffusion of oxygen from inside the cell to outside the cell.

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

What is the function of major histocompatibility complex (MHC) proteins? a. They stimulate cell division. b. They trigger endocytosis of the antigen. c. They promote phagocytosis by binding to antigens. d. They facilitate antigen recognition by T cell receptors.

d. They facilitate antigen recognition by T cell receptors.

What is the function of tropomyosin in muscle cells? a. Tropomyosin is the contractile unit of the muscle cell. b. Tropomyosin binds to actin molecules and brings about shortening of the muscles. c. Tropomyosin stores calcium. d. Tropomyosin covers the myosin binding sites on the actin filaments, preventing contraction from occurring.

d. Tropomyosin covers the myosin binding sites on the actin filaments, preventing contraction from occurring.

If the fluid inside of a cell has a solute concentration of 5%, what would happen if the cell was placed into a solution with a solute concentration of 10%? a. Solute molecules would leave the cell by osmosis. b. Water molecules would enter the cell by osmosis. c. There would be no movement of water molecules in either direction. d. Water molecules would leave the cell by osmosis. e. Water molecules would cross the membrane in both directions, but there would be no net movement of water molecules.

d. Water molecules would leave the cell by osmosis.

Which of the hormonal changes would lead to a decrease in testosterone production by Leydig cells? a. an increase in GnRH production b. None of the other answer options is correct. c. an increase in FSH production d. a decrease in LH production

d. a decrease in LH production

Which of these hormones increases blood pressure by directly stimulating the distal convoluted tubule and collecting ducts to take up more water and salts? a. angiotensin II b. renin c. angiotensin I d. aldosterone e. antidiuretic hormone

d. aldosterone

the two main classes of hormones are: a. steroid hormones and lipid hormones. b. polysaccharide hormones and protein hormones. c. nucleic acid hormones and lipid hormones. d. amine/peptide hormones and steroid hormones.

d. amine/peptide hormones and steroid hormones.