MCAT Subject Tests Dear Future Doctor, The following Subject Test and explanations contains questions not in test format and should be used to practice and to assess your mastery of the foundation content necessary for success on the MCAT Simply memorizing facts is not sufficient to achieve high scores; however, an incomplete understanding of basic science knowledge will limit your ability to think critically Think of building your content knowledge as learning the vocabulary and practicing MCAT-like questions as actually speaking All rights are reserved pursuant to the copyright laws and the contract clause in your enrollment agreement and as printed below Misdemeanor and felony infractions can severely limit your ability to be accepted to a medical program and a conviction can result in the removal of a medical license We offer this material for your practice in your own home as a courtesy and privilege Practice today so that you can perform on test day; this material was designed to give you every advantage on the MCAT and we wish you the best of luck in your preparation Sincerely, Albert Chen Executive Director, Pre-Health Research and Development Kaplan Test Prep © 2003 Kaplan, Inc All rights reserved No part of this book may be reproduced in any form, by Photostat, microfilm, xerography or any other means, or incorporated into any information retrieval system, electronic or mechanical without the written permission of Kaplan, Inc This book may not be duplicated, distributed or resold, pursuant to the terms of your Kaplan Enrollment Agreement  _ B I O L O G Y S U B J E C T T E S T Biology Subject Test Which enzyme changes disaccharides to monosaccharides? A B C D E A heart beat is initiated by the pacemaker, which is also known as the atrioventricular (AV) node also known as the sinoatrial node located in the wall of the right ventricle functionally dependent upon nervous stimulation E located in the brain In the nervous system A myelination of nerves permits faster rates of impulse conductance B an excitatory neurotransmitter causes hyperpolarization of the post-synaptic membrane C the autonomic nervous system mediates voluntary functions D during an action potential, first K+ rushes in E during an action potential, first K+ rushes out of the cell and then Na+ rushes in In the digestive system, all of the following are true except A digestive enzymes from the pancreas are released via a duct into the duodenum B peristalsis is a wave of smooth muscle contraction that proceeds along the digestive tract C in the small intestine, villi absorb nutrients into both the lymphatic and circulatory systems D the low pH of the stomach is essential for the function of carbohydrate digestive enzymes E the release of bile from the gall bladder is triggered by the hormone cholecystokinin A Mature red blood cells are not nucleated B Blood platelets are involved in the clotting process C The adult spleen is a site of red blood cell development D White blood cells are capable of phagocytosing foreign matter E New red blood cells are constantly developing in the bone marrow Lactase Kinase Zymogen Lipase Phosphorylase A B C D Which of the following statements about blood is false? Which of the following is a normal pathway of blood flow? A B C D E Right ventricle to aorta Pulmonary veins to left atrium Inferior vena cava to left atrium Pulmonary veins to left ventricle Left ventricle to pulmonary artery In the kidney A nephrons are located only in the cortex of the organ B ammonia is converted to urea C both glucose and water are actively reabsorbed from the glomerular filtrate D antidiuretic hormone causes the reabsorption of water from the collecting tubule E filtration of the blood begins at the glomerulus and ends at the loop of Henle Which of the following associations of brain structure and function is false? A B C D E Hypothalamus : appetite Cerebellum : motor coordination Cerebral cortex : higher intellectual function Reticular activating system : sensory processing Medulla : basic emotional drives KAPLAN B I O L O G Y S U B J E C T T E S T 13 Which statement about the menstrual cycle is false? Which pairing of digestive enzyme and type of substrate is incorrect? A B C D E Ptyalin (salivary amylase) : proteins Chymotrypsin : proteins Carboxypeptidase : proteins Pancreatic amylase : carbohydrates Pancreatic lipase : fats A FSH causes the development of the primary follicle B LH causes the graafian follicle to undergo ovulation C The corpus luteum develops from the remains of the post-ovulatory graafian follicle D As a follicle develops, it produces estrogen E FSH and LH are both posterior pituitary secretions 10 Which of the following statements about muscles is false? A During isometric contraction the length of the muscle is constant B During isotonic contraction the length of the muscle shortens C In a resting muscle there is complete relaxation D Tonus is the state of partial contraction that occurs in the resting muscle E Tetanus is a condition of sustained contraction due to an overlap of twitch impulses 11 Which statement about the respiratory system is NOT true? A Ciliated nasal membranes warm, moisten, and filter inspired air B Contraction of the diaphragm enlarges the thoracic cavity C When the thoracic cavity enlarges, the pressure of air within the lungs falls D When the pressure of air within the lungs is less than the atmospheric pressure, air will flow out of the lungs E The respiratory process consists of inspiratory and expiratory acts following one another 14 Which statement about pancreatic endocrine function is FALSE? A Glucagon and insulin are both produced by islets of Langerhans cells B Glucagon and insulin are mutually antagonistic in their behavior C Glucagon and insulin both cause glucose to be removed from the bloodstream and stored as glycogen D Glucagon causes an elevation in the level of serum glucose E Insulin causes a decrease in the level of serum glucose 15 Which of the following is an incorrect pairing of an endocrine gland and hormone secretion? A B C D E Posterior pituitary : LH Adrenal cortex : aldosterone Anterior pituitary : TSH Adrenal medulla : epinephrine Hypothalamus : FSH-releasing factor 16 What is the correct order that the body uses energy sources? 12 All of the following statements about hormones are true EXCEPT A they are transported by the circulatory system B they bind to receptors on target cells C they must be present in large quantities to have an effect D they are secreted by endocrine glands E they can affect organs of the body that are far removed from their site of synthesis A B C D E glucose ∅ fats ∅ proteins ∅ other carbohydrates glucose ∅ other carbohydrates ∅ proteins ∅ fats glucose ∅ other carbohydrates ∅ fats ∅ proteins fats ∅ glucose ∅ other carbohydrates ∅ proteins fats ∅ proteins ∅ glucose ∅ other carbohydrates KAPLAN _ B I O L O G Y S U B J E C T T E S T 17 Which statement about human gamete production is false? A In the testes, sperm develop in the seminiferous tubules B In the ovaries, eggs develop in the ovarian follicles C FSH stimulates gamete production in both sexes D Gametes arise via meiosis E The result of meiosis in females is the production of four egg cells 18 Which of the following statements about evolution is correct? A Lamarck's theory of use and disuse adequately describes why giraffes have long necks B Darwin's theory of natural selection relies solely on genetic mutation C Darwin's theory explains the evolution of man from present day apes D Darwin's theory of natural selection relies solely on environmental conditions E Natural selection is the process in which random mutations are selected for survival by the environment 19 Where are amino acids absorbed? A B C D E small intestine large intestine gall bladder stomach rectum 20 The hormone progesterone A stimulates follicle growth B shuts off FSH production C prepares the uterus for implantation of the zygotes D is solely responsible for the maintenance of secondary sex characteristics E is produced by the anterior pituitary 21 To ensure survival of their species, animals that not care for their young must A B C D E have the ability to live in water and on land lay eggs produce many offspring have protective coloring have internal fertilization 22 Cerebellum damage will most likely A B C D E impair memory impair coordination and equilibrium impair sense perception impair pituitary function impair breathing function 23 Basal metabolism disorders are most likely caused most directly by A B C D E impairment of the pituitary impairment of the gonads impairment of the thyroid impairment of the thymus impairment of the parathyroid 24 In the adult man, red blood cells are A non-nucleated and cannot repair themselves B replaced in the liver C outnumbered by white blood cells in the circulation D made in the spleen E sites of rapid protein synthesis 25 Which of the following is NOT reabsorbed from the glomerular filtrate? A B C D E glucose Na+ ClK+ amino acids KAPLAN B I O L O G Y S U B J E C T T E S T 26 Estrogen A maintains female secondary sex characteristics B promotes development of the follicle C induces the ruptured follicle to develop into the corpus luteum D lowers blood glucose E stimulates testosterone synthesis in males 27 You've just been stopped for going 90mph in a 55mph zone and this tickets means your license will be suspended As the police officer approaches your car, which of the following is NOT occurring? A B C D E Increased blood pressure Increased heart rate Dilated bronchioles Release of acetylcholine into the blood Increased pupil diameter 28 The oxygen content is greatest in the fluid in which of the following structures? A B C D E Pulmonary artery Thoracic duct Right atrium Left ventricle Inferior vena cava 29 What is the correct sequence of passages that air travels through during exhalation? A alveoli ∅ bronchi ∅ bronchioles ∅ trachea ∅ pharynx B alveoli ∅ bronchi ∅ lungs ∅ trachea ∅ pharynx C alveoli ∅ trachea ∅ bronchi ∅ larynx ∅ pharynx D alveoli ∅ bronchi ∅ trachea ∅ larynx ∅ pharynx E alveoli ∅ bronchi ∅ trachea ∅ pharynx ∅ larynx 30 The rate of breathing is controlled by involuntary centers in the A B C D E cerebrum cerebellum medulla oblongata spinal cord hypothalamus 31 Bones are connected to each other by connective tissue known as A B C D E sockets tendons ligaments synovia muscles 32 Examples of environmental factors affecting the way a gene is expressed include all of the following except A Drosophila with a given set of genes have crooked wings at low temperatures and straight wings at high temperatures B the change in hair color of the Himalayan hare after cooling the naturally warm portions C the production of heat shock proteins in a cell after an increase in temperature D a decrease in temperature causing shivering E All of the above 33 Which of the following is not a disorder of the eye? A B C D E Myopia Hypermetropia Glaucoma Cataracts All of the above are disorders of the eye 34 Which statement concerning the pituitary gland is false? A The anterior pituitary secretes hormones involved in the menstrual cycle B The posterior pituitary directs the action of the thyroid gland C The hypothalamus secretes factors that cause the release of anterior pituitary hormones D Growth hormone is an anterior pituitary secretion E The posterior pituitary can affect blood pressure 35 Which of the following is not a lipid derivative? A B C D E Waxes Steroids Carotenoids Albumins Lecithin KAPLAN _ B I O L O G Y S U B J E C T T E S T 36 Which of the following statements about viruses is NOT true? A B C D The genetic material may be DNA or RNA The virus may replicate in a bacterial host The virus may replicate in a eukaryotic host The virus may replicate autonomously in the absence of a host E The protein coat of the virus does not enter a host bacterial cell 37 In the kidney, blood filtered through the glomerulus does not normally contain A B C D E glucose amino acids blood cells sodium ions potassium ions 40 Which statement about acetylcholine (ACh) is NOT true? A ACh is released at the neuromuscular junction B ACh binds to specific receptors on the postsynaptic membrane C In a synaptic cleft there are enzymes that degrade ACh D ACh diffuses through the pre-synaptic membrane after its synthesis E A synapse that is subjected to many action potentials may be depleted of ACh granules STOP! END OF TEST 38 According to Starling's hypothesis of capillary physiology, which of the following is true? A The hydrostatic pressure is lower at the arteriolar end B The osmotic pressure tends to keep fluid out of the vessel C Filtration occurs where the hydrostatic pressure is less than the osmotic pressure D The ultrafiltrate is returned to the bloodstream by the lymphatic system E None of the above 39 Renin is a polypeptide produced A B C D E in response to decreased blood pressure in response to increased blood volume in response to a concentrated urine which acts on the pituitary gland in the proximal convoluted tubules of the kidney KAPLAN B I O L O G Y S U B J E C T T E S T BIOLOGY SUBJECT TEST ANSWER KEY A A 17 E 25 D 33 E B 10 C 18 E 26 A 34 B D 11 D 19 A 27 D 35 D D 12 C 20 C 28 D 36 D C 13 E 21 C 29 D 37 C A 14 C 22 B 30 C 38 D B 15 A 23 C 31 C 39 A E 16 C 24 A 32 D 40 D KAPLAN _ B I O L O G Y S U B J E C T T E S T EXPLANATIONS A Lactase breaks lactose into glucose and galactose Answer choice B is incorrect because kinase is an enzyme that phosphorylates its substrate Answer choice C is incorrect because zymogen is an enzyme that is secreted in an inactive form The zymogen is cleaved under certain physiological conditions to the active form of the enzyme Important examples of zymogens include pepsinogen, trypsinogen, and chymotrypsinogen, which are cleaved in the digestive tract to yield the active enzymes pepsin, trypsin, and chymotrypsin Answer choice D is incorrect because lipase breaks down lipids into free fatty acids Answer choice E is incorrect because phosphorylase removes a phosphate from its substrate B The heartbeat is initiated by the sinoatrial (SA) node located in the wall of the right atrium and travels through the atria It is regulated but not controlled by the accelerator nerve (sympathetic) and the vagus nerve (parasympathetic) It is then picked up by the AV node which signals the bundle of His (AV bundle) which transports the contraction through the ventricles via the Purkinje fibers Answer choice A is incorrect because while the AV node does have contractile ability and controls the contraction of the ventricles, it does not control the contraction of the entire heart and is not as regular as the signal from the SA node Answer choices C and D are not correct because the SA node is located in the wall of the right atrium and is not functionally dependent upon nervous stimulation as this tissue initiates the heartbeat although it can be modified by the nervous system D The low pH of the stomach is essential for the function of the enzymes that break down proteins into their amino acids Answer choice A is true: amylases, lipases, and bicarbonate are released through the pancreatic duct Answer choice B is true: peristalsis propels food and waste through the system Answer choice C is true because glucose and amino acids are picked up by the blood while fats are picked up by lacteals, which are special vessels that connect with the lymphatic system Answer choice E is true because cholecystokinin is a hormone released by the wall of the small intestine due to the presence of acidic chyme from the stomach It stimulates the gall bladder to release bile and the pancreas to release digestive enzymes Both secretions are released into the duodenum D ADH is released by the posterior pituitary gland and causes the collecting tubule to be more permeable to water Therefore, more water is absorbed and urine becomes more concentrated Answer choice A is incorrect because in the nephrons, the glomerulus, Bowman's capsule, and the proximal and distal convoluted tubule are in the cortex while the loop of Henle and the collecting tubule are in the medulla Answer choice B is incorrect because ammonia is transformed into urea in the liver and excreted by the kidney Answer choice C is incorrect because salts, glucose, and amino acids are reabsorbed by active transport while water is reabsorbed by diffusion Answer choice E is incorrect because filtration only occurs at the glomerulus and Bowman's capsule C In the adult, all hematopoiesis occurs in the bone marrow In the fetus, hematopoiesis occurs in the fetal liver The spleen acts as a reservoir for red blood cells and filters the blood Answer choice A is true because mature red blood cells are not nucleated in order to create more space for hemoglobin Answer choice B is incorrect because blood platelets are crucial for the clotting of blood, and answer choice D is incorrect because certain white blood cells such as macrophages and neutrophils engulf foreign matter, and answer choice E is incorrect because new blood cells are continually being produced in the bone marrow to replace the cells after their life span of 120 days has ended KAPLAN B I O L O G Y S U B J E C T T E S T A Myelin is a fatty compound that surrounds the axons and has been compared to insulation on a wire It speeds conduction along the nerve cell, and is produced by Schwann cells Answer choice B is incorrect because depolarization actually occurs after release of an excitatory neurotransmitter Hyperpolarization actually makes it more difficult for an action potential to occur Answer choice C is incorrect because the autonomic nervous system is made up of the sympathetic and parasympathetic nervous systems and regulates involuntary actions with opposing results Answer choices D and E are incorrect because sodium channels open first and Na+ rushes in, then K+ channels open and release potassium out of the cell B Blood traveling from the left ventricle will flow into the aorta, then go to all areas of the body except the lungs For example, blood in the brachiocephalic artery will travel to the head and the shoulders, and blood in the renal artery will travel to the kidney to be filtered Blood will go from these arteries into arterioles, then capillaries, where food, waste, and energy will be exchanged Then the blood will go into venules and collect in veins, and will be transported to the superior and inferior vena cavae This makes up the systemic circulation Then the blood will enter the right atrium and flow into the right ventricle After this it will be transported to the lungs via the pulmonary artery where capillary beds will surround the alveoli so gas exchange can occur Then the pulmonary veins will bring it back to the left atrium to start the process over again This is known as pulmonary circulation Looking at the answer choices, only B follows this flow chart E The medulla monitors blood carbon dioxide levels and pH, and adjusts breathing, temperature, and heart rate It is also the center for reflex activities such as coughing, sneezing, and swallowing Answer choice A is true because the hypothalamus is the center that controls thirst, hunger, sleep, blood pressure, and water balance Answer choice B is true because the cerebellum controls muscle coordination and tone, and maintains posture Answer choice C is true because the cerebral cortex is the center for vision, hearing, smell, voluntary movement, and memory Answer choice D is true because the reticular activating system receives and sorts sensory input A Salivary amylase digests starch into maltose All the other enzymes are correctly paired with their substrates 10 C Even in resting muscles there is a slight contraction known as tonus Answer choice A is true because in isometric contraction, there is constant length and an increase in muscle tension Answer choice B is true because in isotonic contraction, the muscle shortens while the tension remains constant Answer choice D is true because tonus is the partial sustained contraction in relaxed muscles Answer choice E is true because in tetanus, there is no complete recovery before the next sustained contraction This will cause muscle contraction until fatigue because of lack of energy or a build up of waste occurs 11 D Answer choice D is false and therefore the correct answer because when the pressure of air within the lungs is less than atmospheric, air actually rushes into the lungs Answer choices B and C are correct because there is low pressure inside the thoracic cavity due to the expansion of the thoracic volume when the diaphragm contracts Answer choice A is true because when this pressure drops, air rushes in and the ciliated membranes warm, moisten, and filter the inspired air Air then travels through the bronchi, into the bronchioles and finally into the alveoli where diffusion occurs to oxygenate the blood and release CO2 carried back from the tissue KAPLAN _ B I O L O G Y S U B J E C T T E S T 12 C Hormones are capable of being effective at picomolar concentrations Answer choices A and D are true because they are transported by the circulatory system after being secreted by the endocrine (ductless) glands Answer choice E is true because they may travel far from their site of synthesis to have an effect on their target organ Answer choice B is true because cells will respond to hormones only if they have the appropriate receptor on their cell surface in the case of peptide hormones, or inside their cytoplasm in the case of steroid hormones 13 E FSH and LH are secreted by the anterior pituitary, and affect the maturation of the follicle FSH stimulates the production of estrogen, and aids in the maturation of the primary follicle LH causes the corpus luteum to secrete progesterone, which causes the uterine lining to thicken to prepare for implantation 14 C The pancreas is a dual organ with both endocrine and exocrine functions Its exocrine function is to release digestive enzymes and bicarbonate into the small intestine via the pancreatic duct Its endocrine function is to release insulin, produced by the b cells in the islets of Langerhans, and glucagon, produced by a cells, into the bloodstream These antagonistic molecules work together to regulate levels of blood glucose Insulin causes a decrease of blood glucose by stimulating the formation of glycogen Glucagon causes an increase in blood glucose by catabolizing the breakdown of glycogen into glucose 15 A The posterior pituitary only secretes ADH and oxytocin Answer choice B is correct because the adrenal cortex does secrete aldosterone, which is a mineral cortisone that causes the increase of absorption of Na+ Answer choice C is correct because the anterior pituitary does secrete TSH, which stimulates thyroid production of thyroxin, which raises the basal metabolic rate Answer choice D is correct because the adrenal medulla does secrete epinephrine, which increases heart rate and blood pressure, and the flow of the blood to skeletal muscle Answer choice E is correct because the hypothalamus secretes FSH-releasing factor, which stimulates the anterior pituitary 16 C When glucose supplies run low, the body utilizes other energy sources These sources are used by the body in the following preferential order: other carbohydrates, fats, and proteins These substances are first converted to either glucose or glucose intermediates, which can then be degraded in the glycolytic pathway and the citric acid cycle Proteins are the last resource for energy because there is no protein storage in the body Utilization of protein results in muscle wasting and connective tissue breakdown, which can be harmful in the long term 17 E Oogenesis produces only one viable egg and two or three polar bodies This is a result of unequal distribution of the cytoplasm during meiosis Answer choice A is true because interstitial cells are stimulated by LH to produce testosterone FSH and testosterone then cause the development of sperm in the seminiferous tubules Answer choice B is true because eggs develop in follicles in the ovaries under the control of FSH Answer choice C is true because obviously FSH plays a role in gamete production in both sexes Answer choice D is true because gametes become haploid through reductional division (meiosis) in which a diploid cell gives rise to four haploid sperm or one haploid egg and two or three polar bodies KAPLAN B I O L O G Y S U B J E C T T E S T 18 E This statement is correct Natural selection is the process by which mutations are "tried out" in the environment and if they offer some degree of fitness, they will be passed on to the next generation Answer choice A, Lamarck's theory, was if something was used, such as a giraffe stretching its neck until it became longer, these acquired traits would be passed on to the next generation We know, however, that acquired characteristics not affect the genes, and are therefore not passed on to the next generation Answer choice B is incorrect because Darwin's theory is much more than mutation It is based on overreproduction, which allows for genetic variation among the offspring These offspring are then selected on whether their genetic makeup is the most fit, and these most fit organisms will pass on their genes to the next generation Answer choice C is incorrect because Darwin believed that man and apes actually evolved from a common ancestor And answer choice D is incorrect because natural selection includes selection pressures but also needs a population with genetic variation in order to select the most fit organisms 19 A The small intestine is where chemical digestion is completed and absorption takes place The small intestine is highly adapted to absorption due to it's large surface area formed by finger-like projections called villi Amino acids and monosaccharides pass through the villi walls and enter into the capillary system within the villi Choice B, the large intestine, functions in the absorption of salts and water Choice C, the gall bladder, stores the bile prior to its release in the small intestine Choice D, the stomach, is a large muscular organ that stores, mixes and partially digests food Choice E, the rectum, provides for transient storage of feces prior to elimination through the anus 20 C Progesterone readies the uterus for implantation by thickening and vascularizing the uterine lining Answer choice A is incorrect because FSH secreted by the anterior pituitary actually stimulates follicle growth Answer choice B is incorrect because the production of estrogen by the ovaries actually shuts off FSH secretion Answer choice D is incorrect because estrogen and testosterone are responsible for the secondary sex characteristics of females and males respectively Answer choice E is incorrect because FSH and LH are produced by the anterior pituitary 21 C There are many types of fertilization/development/care in nature At one end of the spectrum would be internal fertilization, internal development, and lots of care These organisms, such as elephants, produce few offspring but a large percentage of the offspring produced reach adulthood The other end of the spectrum would be external fertilization, external development, and no care These organisms, such as many species of fish, must produce large numbers of both eggs and sperm as relatively few eggs and sperm will even interact to produce a zygote Then, without any protection, these zygotes are susceptible to predation Therefore, millions of eggs and sperm must be released in order to perpetuate the species Answer choice A does not help these organisms at all, and while answer choice D might be useful, it is not related to whether or not the young are cared for 22 B The cerebellum is involved in fine motor coordination, balance, and equilibrium so damage to this section of the brain will result in loss of these functions A patient might become jerky and have erratic fine motor skills and lose his balance easily Answer choices A and C would result after trauma to the cerebrum, and answer choice D would result in the impairment of a large number of body functions that depend on hormones secreted by the pituitary gland Answer choice E would result after damage to the medulla oblongata, which controls breathing rates 10 _ KAPLAN _ B I O L O G Y S U B J E C T T E S T 23 C The thyroid gland controls the basal metabolic rate through release of thyroxin It is stimulated by TSH released by the anterior pituitary gland Answer choice A is incorrect because impairment of the pituitary would result in a myriad of disorders as the anterior and posterior pituitary glands secrete a large number of hormones such as ACTH, LH, FSH, ADH, and GH, which control a large number of bodily functions Answer choice B is incorrect because impairment of the gonads would result in a loss of FSH and LH from the anterior pituitary Answer choice D is incorrect because the thymus is involved in the development, maturation, and education of T cells Answer choice E is incorrect because parathyroid hormone stimulates calcium resorption from bone and increases plasma Ca2+ levels as a result 24 A Red blood cells are produced in the bone marrow They lose their nucleus to make room for more hemoglobin so they cannot reproduce, repair themselves, or make proteins Answer choice C is incorrect because RBCs actually highly outnumber leukocytes, and answer choice D is incorrect because the spleen stores a reservoir of red blood cells and acts as a biological and physical filter for the blood 25 D K+ is considered a waste product and is secreted into the distal convoluted tubule Glucose and amino acids are reabsorbed in the proximal convoluted tubule Na+ and Cl- are reabsorbed everywhere but the descending limb and collecting duct Water is reabsorbed everywhere but the ascending limb (where only salt is pumped out) 26 A Estrogens are steroid hormones necessary for normal female maturation Estrogen stimulates the development of the female reproductive tract and contributes to the development of secondary sexual characteristics and sex drive Estrogens are also secreted by the follicle during the menstrual cycle and are responsible for the thickening of the endometrium Choice B is incorrect because it is FSH released from the anterior pituitary that promotes the development of the follicle, which matures and begins secreting estrogen Choice C is describing the function of LH in the female menstrual cycle Choice D is describing insulin function Insulin is a protein hormone secreted in response to a high blood glucose concentration and stimulates the uptake of glucose by muscle and adipose cells Choice E is another function of LH 27 D The situation described would stimulate the sympathetic nervous system Acetylcholine is a neurotransmitter and is not released into the bloodstream Also, acetylcholine is the primary neurotransmitter in a parasympathetic nervous response, not sympathetic Choices A, B, C and E are all responses stimulated by the sympathetic nervous system The primary neurotransmitter for this nervous system is norepinephrine 28 D Blood in the left ventricle has just returned from the lungs where it was oxygenated via the pulmonary vein This is the only vein in the adult body that carries oxygenated blood Answer choice A is incorrect because the pulmonary artery is blood on its way to the lungs to be oxygenated It is actually the most deoxygenated blood in the body Answer choice B KAPLAN _ 11 B I O L O G Y S U B J E C T T E S T is incorrect because lymph vessels such as the thoracic duct are returning lymphatic fluid back to the venous circulation They have a very low partial pressure of O2 Answer choice C is incorrect because the right atrium has a low O2 content as blood returning from the body is collected here before being transported to the lungs Answer choice E is incorrect because the inferior vena cava returns deoxygenated blood to the heart from the lower half of the body 29 D The exhalation process begins in the alveoli then goes through the bronchioles to the bronchi, then it travels through the trachea where it passes through the larynx and then the pharynx 30 C The breathing center in the medulla oblongata monitors the increase in CO2 through its sensory cells It also will detect a decrease in pH in the blood, which is also indicative of an increase of CO2 levels in the blood A decrease in O2 is monitored peripherally by chemoreceptors in the carotid bodies in the carotid arteries, and aortic bodies in the aorta Answer choice A is incorrect because the cerebrum is involved in sensory interpretation, memory, and thought Answer choice B is incorrect because the cerebellum is involved in fine motor coordination, balance, and equilibrium Answer choice D is incorrect because the spinal cord relays sensory and motor information to and from the brain Answer choice E is incorrect because the hypothalamus regulates hunger, thirst, body temperature, sex drive, and emotion 31 C Ligaments are fibrous connective tissue that link bone to bone, while answer choice B is incorrect because tendons are fibrous connective tissue that connect bone to muscle Answer choice A is incorrect because sockets are types of joints such as the ball and socket joint of the hip Answer choice D is incorrect because the synovia is the lining of synovial joints and are meant to ease the friction between bones Answer choice E is incorrect because muscles actually connect bones via their origin and insertion points, but they are not connective tissue Rather they are contractile tissue 32 D Genes supply the hereditary background, but the environment determines the way in which the gene is expressed Thus, the genetic and environmental factors interact to produce the phenotype of the individual Answer choices A, B, and C are all examples of the environment affecting what genes are transcribed Answer choice D is an example of a change in environment causing an effect to maintain homeostasis Shivering generates heat because muscles are contracting rapidly 33 E In myopia (nearsightedness), the image forms in front of the retina In hypermetropia (farsightedness), the image forms behind the retina Glaucoma is an increase of pressure in the aqueous humor due to the blocking of the outflow of the aqueous humor Cataracts occur when the lens becomes opaque and no light can enter the eye, resulting in blindness 34 B The anterior pituitary secretes Thyroid Stimulating Hormone (TSH), which directs the action of the thyroid gland Choice A is incorrect because the anterior pituitary secretes Follicle Stimulating Hormone (FSH), which stimulates follicle maturation and estrogen release, and Luteinizing Hormone (LH), which causes ovum release and progesterone release The hypothalamus, choice C, secretes several hormones into the hypothalamic portal system that controls the release of the anterior pituitary hormones An example is GnRH, which controls the release of FSH and LH 12 _ KAPLAN _ B I O L O G Y S U B J E C T T E S T Growth hormone, choice D, is secreted by the anterior pituitary HG promotes bone and muscle growth, and is involved in fat metabolism The posterior pituitary can affect blood pressure, choice E, through the action of AntiDiuretic Hormone (ADH, vasopressin) ADH can indirectly increase blood pressure by increasing blood volume by increasing water reabsorption in the nephron 35 D Albumins are globular proteins that act as carriers, enzymes, and have a variety of other functions in the body Waxes are esters of fatty acids and monohydroxylic alcohols They are found as protective coatings on skin, fur, leaves of higher plants, and on the cuticle of the exoskeleton of many insects Steroids such as cholesterol and estrogen have three fused cyclohexane rings and one fused cyclopentane ring Carotenoids are fatty acid-like carbon chains containing conjugated double bonds and carrying six-membered carbon rings at each end These compounds are pigments and they produce red, yellow, orange, and brown colors in plants and animals Lecithin is an example of a phospholipid Phospholipids contain glycerol, two fatty acids, a phosphate group, and nitrogen-containing alcohol 36 D A virus is a simple non-living organism that takes on living characteristics when it enters cells that support its replication They are made up of genetic material, either DNA or RNA, and a protein coat, and must replicate within its host cell A bacteriophage will inject its DNA into the bacterium while leaving the protein coat on the cell surface In eukaryotes, however, the whole virus may enter the cell and not become unencapsulated until it enters the cytoplasm 37 C The glomerulus is a capillary ball in the nephron where glucose, water, amino acids, ions, and urea enter while plasma proteins and cells remain behind Glucose and amino acids are filtered and completely reabsorbed, while urea is filtered and excreted, and Na+ and other salts are filtered and partially reabsorbed Therefore, blood filtered through the glomerulus would not contain blood cells 38 D The movement of fluids occurs between the capillaries and the surrounding tissues Plasma proteins and fluids leave at the arterial end of the capillary bed and reenter at the venule end In between they exchange wastes, food, and fluids with the cells There are two forces that affect this movement 1) The hydrostatic pressure, which is greater at the arterial end (and much greater than the osmotic pressure), drives fluid out of the vessels into the interstitial spaces 2) The osmotic pressure, which is greater at the venule end (and much greater than the hydrostatic pressure), drives fluids back into the vessels to be returned to the circulatory system However, according to Starling's hypothesis, all of the fluid cannot be returned to the vessel Instead, some of this fluid travels through the interstitial spaces until it is picked up by the lymphatic system where it is filtered through the lymph nodes and returns to the circulatory system via the thoracic duct 39 A Renin is part of the renin-angiotensin system, which aids in controlling blood pressure in the body When blood pressure falls (due to heavy bleeding for example) renin is released by the kidneys and converts angiotensinogen to angiotensin I Angiotensin converting enzyme (ACE), which is also present in the blood, converts angiotensin I to angiotensin II Angiotensin II causes vasoconstricion (angio = blood vessel; e.g angioplasty: inserting a plastic balloon into a blood vessel; tensin = tense; constrict) resulting in an increase in blood pressure It also causes the release of aldosterone from the adrenal cortex, which opens ion channels in the convoluted tubule of the kidney to increase water resorption Renin is formed by the juxtoglomerular apparatus near the distal convoluted tubule in the nephron It acts indirectly on the adrenal cortex but does not act on the pituitary gland KAPLAN _ 13 B I O L O G Y S U B J E C T T E S T 40 D Acetylcholine (ACh) is released at the neuromuscular junction when vesicles containing this neurotransmitter merge with the membrane ACh diffuses across the synapse and binds to specific receptors on the post-synaptic membrane An enzyme known as acetylcholinesterase degrades ACh very quickly after release in order to prevent constant stimulation of the synapse 14 _ KAPLAN ... _ B I O L O G Y S U B J E C T T E S T Biology Subject Test Which enzyme changes disaccharides to monosaccharides? A B C D E A heart beat is initiated... B I O L O G Y S U B J E C T T E S T BIOLOGY SUBJECT TEST ANSWER KEY A A 17 E 25 D 33 E B 10 C 18 E 26 A 34 B D 11 D 19 A 27 D 35 D D 12 C 20... pre-synaptic membrane after its synthesis E A synapse that is subjected to many action potentials may be depleted of ACh granules STOP! END OF TEST 38 According to Starling's hypothesis of capillary