Biology subject test (1)

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 1 C6H12O6 + O2 ∅ CO2 + H2O This process is completed A B C D E A B C D E in the cytoplasm in the area of the cell membrane in the nucleus in the mitochondria in the area around the ribosomes Which statement about gastrulation is false? A In the amphibian, the initial site of gastrulation occurs at the gray crescent B As a consequence of gastrulation the embryo now consists of two germ layers: ectoderm and endoderm C In the amphibian, the infolding through which blastula cells migrate during gastrulation is called the blastopore D The primitive gut that results from gastrulation is called the archenteron E Mesoderm develops during gastrulation Mesoderm : heart Ectoderm : nervous system Endoderm : intestinal tract Mesoderm : pancreas Ectoderm : epidermis of skin Point Silent Insertion Frameshift All of the above are types of genetic mutations Can self-replicate Can act as a hormone Can catalyze chemical reactions Acts in cell membrane trafficking Can bind foreign materials A typical human gamete A B C D contains a haploid number of genes will always contain an X or Y chromosome is a result of the meiotic process has genetic material that has undergone recombination E All of the above All of the following organelles are membrane-bound except the A B C D E Which of the following is not a type of genetic mutation? A B C D E It is a long filament of RNA It is produced in the nucleolus It has a poly-A tail It has some short double-stranded segments It is the template for protein synthesis Which is not a characteristic of proteins? A B C D E Which of the following associations of germinal tissues and developed tissues is incorrect? A B C D E Which of the following is a characteristic of tRNA? rough endoplasmic reticulum Golgi apparatus nucleus mitochondria ribosome Which statement about cyclic AMP (cAMP) is NOT true? A cAMP is formed from ATP B The enzyme that catalyzes the formation of cAMP is adenylate cyclase C The enzyme that catalyzes cAMP formation is generally located in the cytoplasm D Membrane receptors are capable of activating the enzyme that forms cAMP E cAMP is regarded as a second messenger, since it can trigger a cascade of intracellular reactions after a hormone binds to the cell membrane KAPLAN B I O L O G Y S U B J E C T T E S T 10 All of the following about the Krebs cycle are true EXCEPT A the Krebs cycle occurs in the matrix of the mitochondrion B the Krebs cycle is linked to glycolysis by pyruvate C the Krebs cycle is the single greatest direct source of ATP in the cell D citrate is an intermediate in the Krebs cycle E the Krebs cycle produces nucleotides such as NADH and FADH2 11 Which statement about glycolysis is NOT true? A Glycolysis converts a single molecule of glucose into two molecules of pyruvate B Glycolysis can produce a net total of two ATPs C The end-product of glycolysis can form ethanol, CO2 lactate, and pyruvic acid D During glycolysis FADH2 is produced E During glycolysis NADH is produced 12 Which of the following statements about oxidative phosphorylation is NOT correct? A It occurs on the inner membrane of the mitochondrion B It involves O2 as the final electron acceptor C It produces two ATPs for the FADH2 D It can occur under anaerobic conditions E It involves a cytochrome electron transport chain 13 Glycogen A B C D E is a storage polymer of glucose is found in both animals and plants is degraded by a process called glycogenesis is synthesized by a process called glycogenolysis is an unbranched molecule 14 In a cell that secretes large quantities of protein, such as a pancreatic exocrine cell, there is (are) I an abundance of rough endoplasmic reticulum II a large Golgi apparatus III prominent nucleoli A B C D E I and II II and III I and III I only I, II, and III 15 Cells that are involved in active transport, such as cells of the intestinal epithelium, utilize large quantities of ATP In such cells there are A B C D E high levels of adenylate cyclase activity many polyribosomes many mitochondria high levels of DNA synthesis many lysosomes 16 The process by which a cell engulfs large particulate matter is called A B C D E pinocytosis exocytosis cytokinesis phagocytosis osmosis 17 The genetic code is considered degenerate because A more than one codon can code for a single amino acid B one codon can code for multiple amino acids C more than one anticodon can bind to a given codon D only one anticodon can bind to a given codon E None of the above 18 Which statement regarding protein synthesis is false? A tRNA molecules shuttle amino acids that are incorporated into the protein B tRNA molecules have the amino acid bound to the 3' end of the molecule C The process does not require energy D Ribosomal RNA is needed for proper binding of the mRNA message E The message is read from the 5' end to the 3' end 19 Which statement about the cell plasma membrane is NOT correct? A It serves as a selectively permeable barrier to the external environment B It serves as a mediator between the internal and external environments C In eukaryotes it contains the cytochrome chain of oxidative phosphorylation D It contains phospholipids as a structural component E It contains proteins that in some cases span the membrane KAPLAN _ B I O L O G Y S U B J E C T T E S T 25 Which of the following is a correct association? 20 The basis for the pairing of the two strands of DNA in the double helix is A B C D E covalent bonding ionic bonding hydrogen bonding hydrophobic interactions hydrophilic interactions A Mitochondria : transports materials from the nucleus to the cytoplasm B Lysosome : digestive enzyme for intracellular use C Endoplasmic reticulum : selective barrier for cell D Ribosome : electron transport chain E Polysome : group of Golgi complexes 26 Spermatogenesis and oogenesis differ in that 21 Which statement about the lac operon is NOT correct? A There are structural genes that code for functional proteins B There is a gene that codes for a repressor protein C The promoter is the binding site of RNA polymerase D The repressor protein binds to the operator, halting gene expression E The lac operon is found in leukocytes A spermatogenesis is mitotic while oogensis is meiotic B oogenesis is mitotic while spermatogenesis is meiotic C spermatogenesis produces gametes while oogenesis does not D spermatogenesis produces four haploid sperm cells while oogenesis produces one egg cell and more than one polar body E spermatogenesis involves unequal division of cytoplasm 22 Which of the following statements about enzymes is NOT true? A Their activity is unaffected by genetic mutation B Enzymes may interact with non-protein molecules in order to have biological activity C Enzymes optimally operate at a particular pH D Enzymes optimally operate at a particular temperature E Enzymes are almost always proteins 27 If a male with blood type A marries a female with blood type B, which of the following types is impossible for a first generation child? A B C D E Type B Type A Type O Type AB All types are possible 23 Bacteria have all the following organelles EXCEPT A B C D E ribosomes a cell membrane a cell wall a nucleus a flagellum 24 An individual with type AB antigen on his red blood cells, in an emergency A B C D E may receive a transfusion of type O blood may receive a transfusion of type A blood may receive a transfusion of type B blood All of the above None of the above 28 Polar bodies are formed during A B C D E male mitosis female mitosis male meiosis female meiosis Two of the above 29 The ectodermal germ layers give rise to A B C D E nails, blood vessels, and epidermis adrenal cortex and epidermis neurons and epidermis kidneys, blood vessels, and heart tooth enamel, blood vessels, and epidermis KAPLAN B I O L O G Y S U B J E C T T E S T 30 Red is dominant over white in a certain flower Which of the following is a valid way to test whether a red offspring is homozygous or heterozygous in this flower? I cross it with a red plant that had a white parent II cross it with a red plant that had two red parents 35 Which of the following cells doesn't have DNA in its nucleus? A B C D E Phagocyte Epithelial Erythrocyte Paramecium Sperm III cross it with a white plant A B C D E I only II only I and III only II and III only I, II and III 31 Which of the following is not characteristic of fermentation? A B C D E Anaerobic Glucose requiring Energy producing Oxygen requiring Produces pyruvic acid 32 Which organelle is chiefly responsible for digestive breakdown of the cell during autolysis? A B C D E Pinocytotic vesicle Golgi body Ribosome Mitochondria Lysosome 33 Green (G) is dominant over yellow (g) in peas, and smooth peas (S) are dominant over wrinkled peas (s) Which cross must produce all green, smooth peas? A B C D E GgSs x GgSs Ggss x GGSs GgSS x ggSS GgSs x GGSS None of the above 34 If 18O-labeled glucose is given to a rat, where will the label first appear? A B C D E Exhaled O2 Exhaled CO2 Exhaled H2O Plasma H2O Intracellular H2O 36 If two animals mate and produce viable fertile offspring under natural conditions, we can conclude that A B C D E they both have haploid somatic cells they are both from the same species for any given allele, they both have the same gene their blood types are compatible None of the above 37 Which of the following is (are) derived from the mesoderm? A B C D E Heart Lung epithelium Intestinal mucosa Nerve Two of the above 38 Ribosomes function in aggregates called A B C D E histones nucleoli endoplasmic reticulum the Golgi complex polysomes 39 Unequal division of the cytoplasm occurs in A B C D E production of sperm cells production of egg cells mitosis of an epidermal cell binary fission in bacteria None of the above 40 Which of the following is most likely to result in erythroblastosis fetalis? A B C D E Mother is Rh- and embryo is RhMother is Rh+ and embryo is RhMother is Rh- and embryo is Rh+ Mother and embryo are both Rh+ Mother is Rh+ and father is Rh- KAPLAN _ B I O L O G Y S U B J E C T T E S T THE ANSWER KEY AND EXPLANATIONS BEGIN ON THE FOLLOWING PAGE KAPLAN B I O L O G Y S U B J E C T T E S T BIOLOGY SUBJECT TEST ANSWER KEY D C 17 A 25 B 33 D B 10 C 18 C 26 D 34 B D 11 C 19 C 27 E 35 C E 12 D 20 C 28 D 36 B D 13 A 21 E 29 C 37 A A 14 E 22 A 30 D 38 E E 15 C 23 D 31 D 39 B E 16 D 24 D 32 E 40 C KAPLAN _ B I O L O G Y S U B J E C T T E S T EXPLANATIONS D Respiration begins in the cytoplasm but is completed in the mitochondria The first step of respiration is glycolysis, which occurs in the cytoplasm Pyruvate from this reaction is converted to acetyl CoA, which enters the Krebs cycle in the mitochondria NADH and FADH2 from the Krebs cycle enter the electron transport chain in the cristae, the inner membrane of the mitochondria B The in-pocketing of the blastula during gastrulation actually allows for the formation of the third cell layer, the mesoderm All the other answer choices are true D The ectoderm develops into the skin, the nervous system, and the eyes while the mesoderm develops into the musculoskeletal system and the internal organs The endoderm develops into the digestive tract and is associated with organs such as the pancreas and liver, the respiratory tract, and the bladder lining The pancreas would therefore develop from the endoderm E Point mutations occur when a single nucleotide base is substituted by another A silent mutation is a point mutation that occurs in a noncoding region, or it does not change the amino acid sequence due to the degeneracy of the genetic code A frameshift mutation is either an insertion or deletion of a number of nucleotides These mutations have serious effects on the protein coded for, since nucleotides are read as series of triplets The addition or loss of nucleotides (except in multiples of three) will change the reading frame of the mRNA D tRNA is a smaller type of RNA, which functions as a carrier of amino acid molecules Like mRNA, tRNA is coded for by DNA, but, unlike mRNA, it is a comparatively short ribonucleotide polymer instead of a long filament Although it is largely single-stranded, there are short double-stranded segments in tRNA where the nucleotide chain loops back upon itself mRNA is actually the template for protein synthesis and has a poly-A tail, which plays a role in the degradation of mRNA rRNA is produced in the region of the nucleus known as the nucleolus A DNA is the only molecule capable of self-replication Some functions of proteins are as hormones (chemical messengers), enzymes (catalyze chemical reactions), structural proteins (physical support), transport proteins (carriers of important materials), and antibodies (which bind foreign particles) E During meiosis, the gamete reduces its genetic component from 2n to n resulting in a haploid cell with half the normal chromosome number When a haploid egg and sperm unite they form a diploid organism known as a zygote All ova will contain an X chromosome and all sperm will contain either an X or a Y chromosome These gametes are formed during the two reductional divisions called meiosis During metaphase I of meiosis I, tetrads form and sister chromatids undergo homologous recombination known as crossing over KAPLAN B I O L O G Y S U B J E C T T E S T E The ribosome, found in both prokaryotes and eukaryotes, can be found in the cytoplams or bound to the endoplasmic reticulum It is involved in polypeptide synthesis Membrane-bound organelles are found only in eukaryotes, and include the ER, Golgi apparatus, mitochondria, nuclei, and lysosomes C cAMP is a second messenger triggered after a receptor binds a ligand Ligands (such as hormones and neurotransmitters) will bind their membrane receptors, activating it Through a G-protein intermediate the enzyme adenylate cyclase will be activated, and will covert ATP into cAMP Adenylate cyclase is attached to the inner layer of the phospholiped bilayer; it is not located in the cytoplasm cAMP is responsible for carrying the chemical stimulus into the cytoplam and triggering a response, and so is called a 2o messenger 10 C The single greatest direct source of ATP in the cell is the electron transport chain The Krebs cycle does occur in the matrix of the mitochondria and oxidative phosphorylation (the electron transport chain) occurs in the inner membrane The final product of glycolysis is pyruvate, which is converted into acetyl coA for use in the Krebs cycle Citrate is an intermediate in this cycle (it is the first molecule formed; another term for the Krebs cycle is the Citric Acid cycle) The Krebs cycle only forms two ATP directly, all of the other ATPs that are formed are produced by oxidative phosphorylation (the nucleotides NADH and FADH2 donate their electrons to the electron transport chain) 11 D Answer choice A is true because the first set of respiratory reactions are anaerobic and involve the breakdown of glucose into pyruvate Answer choice B is true because two ATP are required and four are produced leaving a net of two ATP Answer choice C is true because pyruvic acid, the final product of glycolsis can be anaerobically converted to lactic acid in humans and broken down to ethanol & CO2 in yeast (yeast are used to make alcoholic beverages and cause dough to rise) Answer choice E is true because two NADH are produced by glycolysis and will donate their electrons to compound Q in the electron transport chain Answer choice D is false, and therefore the correct answer, because FADH2 is not produced until the Krebs cycle 12 D Oxidative phosphorylation occurs in the cristae of the mitochondria NADH and FADH2 donate their electrons to a series of cytochrome molecules and form an electron gradient, which forms a proton gradient This proton gradient drives a proton pump that is coupled to an enzyme, which produces ATP The donated electrons are ultimately picked up by O2 and form H2O, one of the metabolic wastes of cellular respiration Each FADH2 from the Krebs cycle results in two ATP, while each NADH results in three ATP However, the NADH from glycolysis only produce two ATP due to the energy needed to get their electrons into the mitochondria from the cytoplasm 13 A Glycogen is a storage polysaccharide sometimes known as animal starch It is made usually in the liver as a result of high glucose concentrations in the blood Answer choice B is incorrect because plants not produce glycogen, rather they produce starch Answer choice C is incorrect because glycogen is degraded by a process called glycogenolysis, and answer choice D is incorrect because glycogen is synthesized by a process called glycogenesis Answer choice E is incorrect because glycogen is also a highly branched molecule KAPLAN _ B I O L O G Y S U B J E C T T E S T 14 E If a cell such as a pancreatic exocrine cell is producing large amounts of enzymes for export, lots of protein synthesis will be occurring in the rough endoplasmic reticulum (RER) This process will begin in the nucleus with the transcription of lots of mRNA, which will be translated in the RER into polypeptides These polypeptides will be packaged and modified in the Golgi for export out of the cell This cell would also have a large nucleolus as the nucleolus is the RNA source for the ribosomes 15 C A cell that is involved in active transport, such as the epithelial cells of the intestine, will require large amounts of ATP If a cell utilizes large amounts of ATP, it must produce it in many mitochondria Answer choice A is incorrect because high levels of adenylate cyclase activity is found in cells that are the target cells for hormones Answer choice B is incorrect because many polyribosomes are found in cells that have a high level of protein synthesis Answer choice D is incorrect because high levels of DNA synthesis are found in cells that undergo rapid reproduction and mitosis Answer choice E is incorrect because many lysosomes would be found in phagocytic cells enabling them to digest the foreign material they've endocytosed 16 D Phagocytosis is the process of engulfing large matter such as a bacterium Answer choice A is incorrect because pinocytosis is the process of taking in small amounts of liquid, and answer choice B is incorrect because exocytosis is the process of releasing proteins from the cell Answer choice C is incorrect because cytokinesis is the division of the cytoplasm during mitosis, and answer choice E is incorrect because osmosis is the movement of water from an area of lower solute to an area of higher solute concentration 17 A The degeneracy of the genetic codes describes how it is not precise or specific More than one codon can code for each of the different amino acids For example, both UAU and UAC code for tyrosine Since there are three bases in a codon, there are 64 possible codons and only 20 amino acids Obviously, there will be some repeating of amino acids among the codons Answer choice B is the opposite of answer choice A and therefore not true Answer choice C is incorrect because it is essential that the anti-codon be the exact base pair complement of the codon to maintain protein integrity Answer choice D is true, but not the definition of the degenerate genetic code 18 C Protein synthesis does require energy Answer choice A is true because tRNA brings the amino acid to the ribosome where it interacts with the mRNA with the proper sequence Answer choice B is true because tRNA molecules have the amino acid bound to their 3' end The mRNA is read from 5' to 3' as the ribosome moves along the message Answer choices D and E are both true 19 C The plasma membrane separates the cellular contents from the environment and is responsible for the permeability of the membrane and what is allowed in and out The fluid mosaic model of the plasma membrane states that it is a bilayer of phospholipid interspersed with proteins acting as receptors, pores, and channels The pores and channels cross the entire membrane The cytochrome chain is actually located in the cristae (the inner membrane) of the mitochondria KAPLAN B I O L O G Y S U B J E C T T E S T 20 C DNA is a double-stranded helix composed of the purines adenine and guanine, and the pyrimidines cytosine and thymidine Adenine binds with thymidine while guanine binds with cytosine via weak hydrogen bonds These weak bonds enable the helices to separate easily to facilitate DNA replication Answer choice A is incorrect because covalent bonding is characterized by shared electron pairs while answer choice B is incorrect because ionic bonding is characterized by electron transfer These are both strong forms of intermolecular bonds Answer choice D is incorrect because hydrophobic interactions are attractive forces between non-polar molecules while answer choice E is incorrect because hydrophilic interactions are attractive forces between polar molecules 21 E The lac operon is a set of control and structural genes in E coli that allow the digestion of lactose There are three structural genes controlled by an operator found on another part of the genome In the abscence of lactose a repressor protein is bound to the operator, preventing RNA polymerase from binding to the DNA, thus preventing translation of the structural genes However, when lactose is present (and glucose is absent), the repressor is removed and RNA polymerase can attach to the promoter, and translation occurs This is known as an inducible system 22 A Enzymes are biological catalysts composed usually of proteins They work at an optimal temperature and pH, typically around the physiological temperature of 36°C and a pH of 7.2 At higher temperatures the proteins will denature and lose their function They will often have to interact with cofactors such as vitamins or ions for optimal activity Also, mutation will affect the DNA sequence coding for these proteins, leading to an altered polypeptide and often a change in spatial configuration and therefore a change in function 23 D Prokaryotes have no membrane-bound organelles so therefore would not have a nucleus 24 D People with the blood type AB are known as the universal recipients They have both A and B blood group antigens on the surface of their red blood cells Therefore, their blood will have no antibodies to any of the blood antigens and they can receive blood from type A, B, and O donors 25 B Lysosomes are membrane-bound organelles containing digestive enzymes and typically have a low pH Answer choice A is incorrect because mitochondria are involved in cellular respiration, and answer choice C is incorrect because the ER transports polypeptides around the cell and to the Golgi apparatus for packaging Answer choice D is incorrect because the ribosome is the site of protein synthesis, and answer choice E is incorrect because polysomes are groups of ribosomes making lots of the same polypeptide 26 D Spermatogenesis and oogenesis are both gametogenesis in that haploid gametes are produced through reductional division (meiosis) of diploid cells This occurs in the gonads They differ in that in spermatogenesis the cytoplasm is equally divided during meiosis and four viable sperm are produced from one diploid cell In oogenesis, the cytoplasm is divided unequally and only one ovum, with the bulk of the cytoplasm, is produced plus two or three inert polar bodies 27 E A and B blood groups are co-dominant over blood antigen O Therefore if a man heterozygous for blood type A (AO) married a woman heterozygous for blood type B (BO), they could possibly have children with the genotypes AO, BO, OO, or AB Therefore, all blood types are possible in this mating 28 D Polar bodies are haploid, or monoploid, nonfunctional gamete-like cells that are formed during female meiosis Recall that meiosis is a two-stage process In the first stage, a diploid cell undergoes a reduction division to form two haploid cells In the second division, each of those haploid or monoploid cells undergoes a second division to form two haploid or monoploid cells each So there are a total of four haploid or monoploid cells formed from each original diploid germ cell In the case of sperm cells, four functional haploid or monoploid gamete sperm cells are formed In the case of 10 _ KAPLAN _ B I O L O G Y S U B J E C T T E S T egg cells, the first meiotic division involves an unequal division of cytoplasm, and that results in the formation of one large cell and one small cell The large cell will go on to divide again; the smaller cell is known as the first polar body The small cell polar body may then divide again to form two other polar bodies The large cell undergoes a second meiotic division, again unequally dividing the cytoplasm, with the larger resulting cell being the final haploid or monoploid ovum, and the other small cell again becoming a polar body So it is possible that during a female meiotic division that one large ovum or functional egg cell and three polar bodies may be formed Polar bodies are not formed in mitosis, which is how all other cell divisions occur in the body; that is, equal cell divisions that not form sex cells 29 C The ectodermal germ layers give rise to the epidermis of the skin and also the nervous system The endodermis, or endodermal germ layer, gives rise to the lining of the digestive system, its associated glands and organs (such as the liver and pancreas), and the lungs Most of the other organs and systems of the body are mesodermal, including the excretory system, the reproductive system, the muscular and skeletal systems, and the circulatory system In general, on the test, if you cannot identify a particular tissue as being specifically endodermal or ectodermal, there's a very good chance that it is one of the many mesodermal-derived tissues Choices A, B, D, and E all contain tissues or structures that are mesodermal in origin 30 C Let R = dominant red color and r = recessive white color There are two possible red genotypes for the unknown offspring–RR (pure homozygous red) and Rr (heterozygous red) The unknown offspring will be referred to as R_ If the cross in I were performed, crossing R_ with Rr (red plant with a white parent), the you would be able to determine the unknown genotype If there were any white offspring, the unknown genotype must be Rr If only red offspring resulted, then the genotype must be RR If the cross in II were performed, crossing R_ with RR, you would not be able to determine the genotype If the unknown allele was recessive, it would be masked by the homozygous dominant red genotype The only phenotype that can result from a parent that is RR is red, so any white allele would never be exposed If the cross in III were performed, crossing R_ with rr, you would be able to determine the unknown genotype of the offspring If there were any white offspring, the unknown genotype must be Rr If only red offspring resulted, then the genotype must be RR Therefore answer choice C, I and III, is the correct answer 31 D Fermentation is a process that occurs during anaerobic respiration in organisms such as yeast After the yeast begin the respiration process by changing glucose to pyruvic acid, gaining some net ATPs in the process, the pyruvic acid is then changed into ethyl alcohol, a waste product of the fermentation process Fermentation does produce energy, as described in the first set of reactions in which glucose is changed into pyruvic acid It is not, however, oxygen-requiring The oxygen-requiring reactions of respiration occur in aerobic respiration, not in fermentation, and they occur as NADH and FADH2 molecules produced in the Krebs cycle are sent to the electron-transport chain for the production of ATPs The final electron acceptor in these reactions is oxygen However, in fermentation, there is no aerobic stage, and ATP is not produced through a Krebs cycle and electron-transport chain mechanism 32 E The lysosome is a small, membrane enclosed vesicle containing digestive enzymes at a very low pH These enzymes are sometimes used to digest worn-out organelles within the cell In some cells, such as phagocytic cells, they are used to help break down ingested bacteria and foreign material Autolysis is when the lysosomes release there contents into the cytoplasmof a cell, causing cell death Autolysis is a method by which a cell can undergo programmed death, called apoptosis An example of apoptosis is seen during the molding of the human hand during fetal development Answer KAPLAN _ 11 B I O L O G Y S U B J E C T T E S T choice A is incorrect; a pinocytotic vesicle is a small vesicle formed by the cell membrane in order to take into the cell a small particle or drop of liquid Answer choice B is incorrect; a Golgi body, normally located at the end of a section of endoplasmic reticulum, has the function of packaging and modifying proteins The Golgi apparatus may surround these proteins and vesicles for export out of the cell, and may also add or delete sections of these proteins that have been formed Answer choice C is incorrect; ribosomes produce proteins under the direction of messenger RNAs using amino acids, which are present in the cytoplasm Answer choice D is incorrect; mitochondria are the site of cell respiration and all energy-producing processes within the cell They are also known as the "powerhouses" of the cell, as they produce ATPs 33 D Both green and smooth are dominant phenotypes We want to produce only green smooth peas, so we want only dominant phenotype offspring Therefore we must avoid any crossing that may result in the mating or combining of two recessive alleles In choice A, crossing Gg and Gg could result in approximately 1/4 yellow offspring Similarly, in choice B, ss crossed with Ss would produce approximately half wrinkled phenotype offspring In choice C, Gg crossed with gg is likely to produce approximately half yellow offspring Choice D is correct in that one of the parents is a double dominant, in that all offspring will have the dominant phenotype, regardless of the genotype of the other parent 34 B When radioactively-labeled glucose is given to a rat, it will enter the respiration reactions beginning with glycolysis and proceeding through the Krebs cycle and the electron transport chain The glucose will be broken down into pyruvic acid during glycolysis However, at that point, no CO2 is formed As pyruvic acid forms acetyl coenzyme A, CO2 is released, and this CO2 may contain the labeled oxygen Later, as acetyl coenzyme A enters the Krebs cycle and the Krebs cycle reactions occur, more CO2 is released This CO2 may also contain the labeled oxygen Answer choice A is incorrect because we generally not exhale oxygen The only oxygen exhaled is that which is not absorbed into the alveoli Answer choices C, D, and E are all incorrect The water that is formed as a result of respiration is formed from the electrons that are sent down the electron transport chain in the mitochondria, combined with hydrogen ions and molecular oxygen, which is taken in through the lungs This molecular oxygen is the final electron acceptor of the chain Therefore the oxygen in respiratory waste product water comes from the oxygen that is inhaled into the alveoli It does not come from oxygen that is part of the glucose molecule that is respired 35 C DNA is contained within the chromosomes, located within the nuclei of cells Almost all cells contain a nucleus, and this nucleus is responsible for both maintenance and reproduction of the cell On occasion, unusually specialized cells such as erythrocytes, or red blood cells, not contain a nucleus This lack of nucleus, in humans and other mammals, is a specialization related to the ability of the erythrocyte to store additional hemoglobin The function of erythrocytes is to distribute oxygen to the tissues, and additional hemoglobin is advantageous in this function All other human cells would contain a nucleus and DNA Answer choice A is incorrect because phagocytes are leukocytes or white blood cells and contain nuclei Answer choice B is incorrect because epithelial cells are lining cells along the surface of many tissues, and they are also nucleated Answer choice D is incorrect because paramecium is a single-celled protist, and it also contains a nucleus Answer choice E is incorrect because sperm cells also have a nucleus with DNA The only difference between a sperm cell and the other cells mentioned is that sperm cells contain half the DNA; that is, sperm cells are monoploid, which the other cells are diploid 36 B The definition of a species involves organisms that can mate with each other under natural conditions, and this mating produces viable offspring that are themselves fertile Physical or morphological similarity between organisms is not sufficient to make two given organisms the same species Likewise, organisms that may appear quite different from each other (e.g., different breeds of dog) can be shown to be the same species because they can mate and produce fertile offspring Answer choice A is incorrect; somatic cells, which are body cells and not reproductive cells, are never haploid or monoploid Answer choice C is incorrect; organisms can be the same species and yet have different varieties of gene at 12 _ KAPLAN _ B I O L O G Y S U B J E C T T E S T the same gene locus For example, blue-eyed and brown-eyed people can mate and produce fertile offspring Answer choice D is incorrect; there is no relationship between the ability to produce viable, fertile offspring and blood type 37 A As seen in question 5, many of the human body tissues are derived from the mesoderm In answering questions of this type, if you review and eliminate tissues derived from the ectoderm and endoderm, you find that the remaining tissues are mesodermal In this question, answer choices B and C are endodermal tissues Answer choice D is incorrect because nerve is an ectodermal derivative 38 E Large groups of ribosomes collected together and producing the same protein are known as polysomes Answer choice A is incorrect because histones are proteins located within the nucleus but which are not genetic material themselves Recall that genetic material is DNA, but there are associated proteins within the nucleus and chromosomes; some of them are known as histones Answer choice B is incorrect because nucleoli are areas within the nucleus containing RNA The nucleolus is the source of the RNA that forms ribosomes Answer choice C is incorrect because endoplasmic reticulum refers to a set of transfer canals within the cytoplasm through which manufactured proteins are sent Answer choice D is incorrect because the Golgi complex (or Golgi body or Golgi apparatus) are organelles that package and modify proteins made by the ribosomes and sent to the Golgi bodies by the endoplasmic reticulum 39 B Unequal cytoplasm division occurs when egg cells are produced during the meiotic process of oogenesis All meiotic divisions are two stages In the first stage of egg production, also known as oogenesis, the precursor diploid cell produces two daughter cells, but one of the daughter cells receives almost the entire amount of cytoplasm, while the other becomes a nonfunctioning polar body In the second division of oogenesis, the large daughter cell divides again, and once again one of the new daughter cells receives almost all of the cytoplasm, and the other becomes a small nonfunctional polar body The original first polar body may also divide to form two nonfunctional polar bodies The final result is a potential four haploid or monoploid cells, but only one of them—the one that received a greater amount of cytoplasm during each meiotic division—becomes a functional egg cell Answer choice A is incorrect; during spermatogenesis, one diploid precursor cell forms four functional haploid, or monoploid, sperm cells In this case, both divisions are equal, and all sperm cells are equal in amount of cytoplasm Answer choice C is incorrect; during mitosis of epidermal cells cytoplasm is distributed equally Likewise, answer choice D is incorrect; in the binary fission of bacteria, in which bacterial cells are dividing as a means of reproduction, cytoplasmic division will be equal 40 C Erythroblastosis fetalis is a condition also known as Rh incompatibility, in which an Rh+ fetus is developing within an Rh– mother This condition also requires that the father be Rh+ In this case, the Rh- mother may produce antibodies against the Rh proteins present in the fetus This is most likely to occur in second, third, or fourth children, as the first child often sensitizes the mother to Rh protein and causes the formation of antibodies These antibodies are then available when the second Rh+ fetus is present The incompatibility also occurs late in the pregnancy when some potential mixing of maternal and fetal blood occurs Normally the maternal and fetal blood systems are completely separate In order for this problem to occur, the child must contain an antigen that the mother does not have In this case, only the case of a positive fetus and a negative mother will match these conditions KAPLAN _ 13 ... _ B I O L O G Y S U B J E C T T E S T Biology Subject Test 1 C6H12O6 + O2 ∅ CO2 + H2O This process is completed A B C D E A B C D E in the cytoplasm... B I O L O G Y S U B J E C T T E S T BIOLOGY SUBJECT TEST ANSWER KEY D C 17 A 25 B 33 D B 10 C 18 C 26 D 34 B D 11 C 19 C 27 E 35 C E 12 D 20... mitochondrion B the Krebs cycle is linked to glycolysis by pyruvate C the Krebs cycle is the single greatest direct source of ATP in the cell D citrate is an intermediate in the Krebs cycle E the Krebs