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 of the following is in a different chemical category than the others? A B C D E A portal system The contractile vacuole of Euglena decreases its rate of contraction when the organism is transferred from fresh water to sea water This is explained by The chromosome number remains unchanged as a result of A B C D E The distance between linked genes is often measured by A B C D E A an increase in the osmotic pressure of the environment B a decrease in the osmotic pressure of the environment C the nitrogenous wastes can remain in the cell because of a higher salt concentration outside the cell D excess salts are eliminated without the loss of water E salt inhibits the contractile apparatus Which of the following is a correct association? A Mitochondria : transports materials from the nucleus to the cytoplasm B Golgi apparatus : modification and glycosylation of proteins C Endoplasmic reticulum : selective barrier for the cell D Ribosome : digestive enzymes most active at an acid pH E Lysosomes : membrane-bound organelles which convert fat into sugars Cytosine Thymine Arginine Guanine Uracil A receives blood directly from the aorta B carries blood from one set of capillaries through a vein to another set of capillaries C always empties into the liver D is present in the walls of the ventricles E links the small intestine and kidney probability of crossing over frequency of silent mutations histone concentrations distance between ribosomes on mRNA AT/GC ratio Disjunction is defined as A when the paternal chromosomes separate from the maternal chromosomes B when homologous pairs of chromosomes recombine C when the spindle apparatus is formed from the centrioles D when the cell membrane invaginates to form two daughter cells E None of the above Questions 8-12 refer to the choices below meiosis mitosis fertilization non-disjunction in all gametes formed None of the above A Copulation B Fertilization C Meiosis D Mitosis E Gastrulation Method of replication for epithelial cells Tetrads are formed in this process 10 Fusion of the nuclei of two gametes 11 May result in the formation of polar bodies 12 Results in archenteron formation KAPLAN B I O L O G Y S U B J E C T T E S T 13 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 18 PGAL A is considered the prime end product of photosynthesis B can be used immediately as food C can be combined and rearranged to form glucose D can be stored as insoluble polysaccharides such as starch E All of the above 14 Which of the following is NOT a steroid? 19 During what stage of meiosis does crossing over occur? A B C D E Cholesterol Vitamin D Testosterone Thyroxine Cortisol A B C D E Prophase I Metaphase I Anaphase I Telophase I Interkinesis 15 Which of the following cells produce antibodies? 20 The blood group antigens are an example of A B C D E Macrophages B cells T cells Neurons Natural Killer cells 16 The rate of an enzyme catalyzed reaction can be influenced by all of the following EXCEPT A B C D E Substrate concentration Temperature Enzyme concentration Rate constant pH 17 What is the probability of a white, long tailed mouse from the cross of a heterozygous black, heterozygous long-tailed mouse with a homozygous recessive white, homozygous recessive short tailed mouse? A B C D E 0% 25% 50% 75% 100% A B C D E pleiotropy incomplete dominance codominance epistasis incomplete penetrance 21 Sex-linked traits such as hemophilia and colorblindness A B C D E are located on autosomes are always dominant are found in genetic bottlenecks have been selected out of the population are rarely seen in females 22 Cell division A is a mechanism by which a cell halves its organelles and cytoplasm B does not involve DNA replication C is a way for multicellular organisms to grow, develop, and repair D is also known as mitosis E None of the above KAPLAN _ B I O L O G Y S U B J E C T T E S T 23 In Drosophila, the gene for red eyes (w+) is dominant over the gene for white eyes (w) Round eye (B+) is dominant to Bar eye (B) A fly of an unknown genotype is crossed against a white bar eyed fly The phenotypic ratio of the offspring is 25% Red, round eyed 25% Red, bar eyed 25% White, round eyed 25% White, bar eyed 28 Very early in embryonic development, each cell still has the ability to develop into a complete organism This is known as A B C D E indeterminate cleavage determinate cleavage blastulation gastrulation None of the above What is the genotype of the unknown parent? A B C D E w+w+ B+B+ w+w B+B+ w+w BB ww B+B w+w B+B 24 How many ATP are produced from molecules of glucose using only substrate level phosphorylation? A B C D E 36 38 40 25 In the DNA of C elegans, 15% of the bases are guanine, what percentage are thymines? A B C D E 15% 20% 35% 70% 85% 26 Which of the following does not secrete a hormone? A B C D E pituitary gland salivary gland hypothalamus heart kidney 27 In pedigree analysis, which of the following would lead you to assume autosomal dominance? A B C D E The trait skips every other generation The trait shows up in every generation The trait shows up mainly in females The trait shows up mainly in males The trait is always masked by another allele 29 The insertion or deletion of a single nucleotide base in a cell’s DNA results in a A B C D E thymine dimer missense mutation frameshift mutation nonsense mutation degenerate genetic code 30 According to the theory of blood groups, which of the following statements is false? A Type O blood contains no agglutinins B Agglutinins are antibodies C Type A blood contains agglutinins for type B agglutinogens D Agglutinogens are antigens E Rh factor is a type of agglutinogen found in human blood 31 During what stage of cell division chromosomes go from single-stranded to double-stranded? A B C D E Interphase Prophase Metaphase Anaphase Telophase 32 What level(s) of protein structure is characterized by αhelices and β-sheets? A B C D E Primary Secondary Tertiary Quaternary Secondary and tertiary KAPLAN B I O L O G Y S U B J E C T T E S T 33 Axons are sheathed in myelin which A B C D E allows faster conduction of impulses maintains the resting potential allows the pumping of Na+ out of the cell initiates the action potential determines the threshold of the neuron 34 How many genetically different gametes can be formed by a mouse that is genotypically AABbCc? (Assume no linkage between these genes and that none are lethal.) A B C D E 35 Active transport is best defined as A diffusion of soluble substances across a membrane from a region of high concentration to low concentration B osmosis of water across a semi-permeable membrane involving the hydrolysis of polypeptides C the movement of materials across a semipermeable membrane against an electrochemical gradient D the movement of materials across a semipermeable membrane with an electrochemical gradient E the movement of substances across a membrane in accordance with the Donnan equilibrium 38 What is the major difference between prokaryotes and eukaryotes? A B C D E Only eukaryotes have a cell wall Eukaryotes are all autotrophic Eukaryotes lack ribosomes Prokaryotes have no nuclear membrane Prokaryotes have mitochondria 39 In which of the following would you find cristae? A B C D E Endoplasmic reticulum Mitochondria Nucleus Nucleolus Ribosomes 40 Which of the following is not a necessary condition for the Hardy-Weinberg equilibrium? A B C D Random mating Large gene pool Random emigration and immigration Forward mutation rate equals backward mutation rate E No inbreeding STOP! END OF TEST 36 Which of the following cells does not have DNA? A B C D E Phagocyte Epithelial cell Erythrocyte Osteocyte Sperm 37 Continuous muscle contraction causes a buildup of lactic acid because A it is a breakdown product of ADP B it is a degredation product of phosphocreatine C it is a metabolic end-product of anaerobic metabolism D it is a breakdown product of fatty acid degradation E actomyosin contraction releases cross-links of lactate 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 C C 17 B 25 C 33 A B 10 B 18 E 26 B 34 A B 11 C 19 A 27 B 35 C B 12 E 20 C 28 A 36 C B 13 A 21 E 29 C 37 C A 14 D 22 C 30 A 38 D A 15 B 23 E 31 A 39 B D 16 D 24 B 32 B 40 C KAPLAN _ B I O L O G Y S U B J E C T T E S T EXPLANATIONS C Of the compounds listed, answer choices A, B, D, and E are all nitrogenous bases They are present in such compounds as RNA and DNA The nitrogenous bases guanine and adenine are purines, and the nitrogenous bases cytosine, thymine, and uracil are pyrimidines Answer choice C, arginine, is an amino acid and not a nitrogenous base Amino acids are the building blocks for proteins B Portal systems are unusual circulatory arrangements in the body in which there are two interconnected capillary beds In normal non-portal circulation, blood travels from arteries to a capillary bed and back to a vein In portal systems, however, blood travels from an artery to a capillary bed, to a vein, to a second capillary bed, and back to a second vein The two most well-known portal systems in the human body are the hepatic portal system and the hypothalamic portal system In the hepatic portal system, blood leaving the capillary bed of the small intestine, which has picked up digested food, passes through the hepatic portal vein to a capillary bed in the liver before returning to a normal venous system In the hypothalamic portal system, the two capillary beds are contained in the hypothalamus and the anterior pituitary This portal system brings releasing factors from the hypothalamus to the anterior pituitary Answer choice A is incorrect; a portal system may receive blood from the aorta, but this is not its definition Answer choice C is incorrect; a portal system may involve the liver, but there are other systems as previously described Answer choice D is incorrect; there is no portal system within the ventricles of the heart Answer choice E is incorrect; there is no portal system connecting the small intestine and the kidney B The contractile vacuole of Euglena removes excess water from the organism after it comes through the cell membrane osmotically In fresh water, the osmotic pressure drives water inside the organism due to a higher solute concentration with the Euglena The organism must use energy (ATP) to force the water back out When this organism is transferred to salt water, the solute concentration is greater outside the cell, thus the osmotic pressure is smaller This causes water to leave the Euglena The contractile vacuole no longer has to remove water B Mitosis is cellular division that results in the formation of two daughter cells that are genetically identical to each other and to the parent cell The two daughter cells are also diploid (2n) Answer choice A is incorrect because meiosis results in a reduction of chromosome number from 2n to n It is a process of cell division in which two successive nuclear divisions produce four haploid gametes from one diploid germ cell Answer choice C is incorrect because fertilization is the fusion of two haploid (n) gametes into one diploid (2n) zygote Answer choice D is incorrect because non-disjunction results from the failure of homologous chromosomes to separate during meiosis and has chromosome numbers of n+1 or n–1 B The Golgi apparatus consists of a stack of membrane-enclosed sacs The Golgi receives vesicles and their contents from the ER, modifies them (e.g glycosylation) and repackages them into vesicles, and distributes them 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 lysosomes are membrane-bound organelles containing digestive enzymes, and typically have a low pH KAPLAN B I O L O G Y S U B J E C T T E S T A The degree of genetic linkage is a measure of how far apart two genes are on the same chromosome The probability of a crossover and exchange occurring between two points is generally directly proportional to the distance between the points For example, pairs of genes that are far apart from each other on a chromosome have a higher probability of being separated during crossover than pairs of genes that are located close to each other Thus, the frequency of genetic recombination between two genes is related to the distance between them Recombination frequencies can be used to construct a genetic map One map unit is defined as a percent recombinant frequency Recombination frequencies are roughly additive A Disjunction is defined as the separation of maternal and paternal chromosomes during meiosis Each tetrad is separated into two halves One of each pair of chromosomes, each containing two chromatids, is pulled to opposite ends of the cell Note that some of the maternal chromosomes can go to one end and some to the other end The distribution homologues between the two resultant nuclei are random D Epithelial cells are constantly shed from the body and have to be replaced Epithelial cells are indentical to one another, and are produced via mitosis C During prophase I of meiosis I, homologous chromosomes come together and intertwine in a process called synapsis Since at this stage each chromosome consists of two sister chromatids, each synaptic pair of homologous chromosomes contains four chromatids, and is therefore often called a tetrad 10 B Fertilization is defined as the fusion of nuclei of two gametes to form a zygote capable of becoming an adult organism 11 C Oogenesis is a type of meiosis that produces eggs Meiosis I of this process results in two daughter cells known as the secondary oocyte and a small polar body The polar body is formed by an unequal distribution of cytoplasm during splitting of the primary oocyte 12 E Gastrulation results in the formation of the tree primary germ layers and the primitive digestive tract, called the archenteron 13 A 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 Many of the human body tissues are derived from the mesoderm In answering questions of this type, if you review and eliminate tissues derived KAPLAN _ B I O L O G Y S U B J E C T T E S T 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, nerve, is an ectodermal derivative 14 D Thyroxine is a hormone released from the thyroid gland It is not a steroid, but a derivative of the amino acid tyrosine All of the other answer choices are steroids and belong to a class of lipid-derived molecules with a characteristic ring structure Steroid hormones pass through the cell membrane with ease because they are lipid-soluble 15 B Antibodies are produced as a response to the detection of foreign material (e.g viral coat proteins, bacterial cell walls) in the body These antigens are detected by T cells which set the immune response in motion Among their many actions, T cells stimulate B cells to become antibody producing plasma cells, making choice B the correct answer B cells can also be stimulated to become memory cells, which remain dormant in the interstitial fluid and lymphatics until the same antigen is detected again, upon which they can quickly initiate a humoral response Choice A is incorrect because macrophages are phagocytic cells that engulf foreign material (such as bacterial cells) and digest it Choice C, T cells, are the immune response organizers They can become cytotoxic cells (which kill invading cells), helper T cells (which recruit other T and B cells into the battle) and suppresser T cells (which turn the response off when the antigen has been cleared) Choice D is a throw away neurons play no role in the immune response Choice E, natural killer cells, are rouge cells that destroy invading cells that they come across 16 D The rate constant (k) which appears in the rate law is a temperature dependent constant For a given temperature nothing will change k, so it can have no influence on an enzyme catalyzed reaction We can eliminate choice A with the understanding that if the substrate concentration increases the reaction rate will also increase, until you hit a maximum rate (at which point the enzymes become saturated with substrate) Choices B and E are incorrect because all enzymes have an optimal temperature and pH (for most enzymes it is body temperature and plasma pH; 37oC and 7.2 respectively) under which they operate most efficiently If the temperature or pH is increased or decreased from the optimal point, the reaction rate will decrease Choice C is incorrect because an increase in enzyme concentration will cause an increase in reaction rate, so we are left with choice D 17 B Let B = black coat color and b = white coat color and L = long tail and l = short tail So, what is the probability of a white, long-tailed mouse from the cross of BbLl x bbll? Let's construct the Punnett square bl (only possible gamete) BL Bl BbLl Bbll (black, long) (Black, short) bL bl bbLl bbll (white, long) (white, short) So, 25% of the offspring will be black with long tails, 25% of the offspring will be black with short tails, 25% of the offspring will be white with long tails (what we're looking for), and 25% of the offspring will be white with short tails KAPLAN B I O L O G Y S U B J E C T T E S T 18 E PGAL is generally considered the prime end-product of photosynthesis and it can be used as an immediate food nutrient, combined and rearrange to form monosaccharide sugars, such as glucose, which can be transported to other cells, or packaged for storage as insoluble polysaccharides such as starch 19 A During prophase I, the chromatin condenses into chromosomes, the spindle apparatus forms, and the nucleoli and nuclear membrane disappear Homologous chromosomes come together and intertwine in a process called synapsis Sometimes chromatids of homologous chromosomes break at corresponding points and exchange equivalent pieces of DNA; this process is called crossing over Choice B is incorrect During Metaphase I, homologous pairs align at the equatorial plane and each pair attaches to a separate spindle fiber by its kinetochore Choice C is incorrect During Anaphase I, the homologous pairs separate and are pulled to opposite poles of the cell This process is called disjunction and it accounts for a fundamental Mendelian law Choice D is incorrect During Telophase I, a nuclear membrane forms around each new nucleus At this point each chromosome still consist of sister chromatids joined at the centromere The cell divides into two daughter cells, each receiving a nucleus containing the haploid number of chromosomes Choice E is incorrect because interkinesis is a short rest period between the two cell divisions of meiosis and during which the chromosomes partially uncoil 20 C The blood group antigens are an example of codominance Codominance occurs when multiple alleles exist for a given gene, and more than one is dominant When the genotype is heterozygous for codominant alleles, the phenotype is the result of the expression of both alleles simultaneously The classic example of codominance and multiple alleles is the inheritance of ABO blood groups in humans Blood type is determined by three different alleles, IA, IB, and i Only two alleles are present in any single individual, but the population contains all three alleles IA and IB are both dominant to i Individuals who are homozygous IA or heterozygous IAi have blood type A; individuals who are homozygous IB or heterozygous IBi have blood type B; and individuals who are homozygous ii have blood type O However, IA and IB are codominant; individuals who are heterozygous IAIB have a distinct blood type, AB, which combines characteristics of both the A and B blood groups Choice A is incorrect because pleiotropy is the ability of a single gene to have multiple effects Choice B is incorrect Some progeny phenotypes are apparently blends of the parental phenotypes This is known as incomplete dominance Choice D is incorrect: Epistasis is a phenomenon in which one gene alters the expression of another gene that is independently inherited Choice E is incorrect Penetrance is the proportion of individuals who show the phenotype that is expected from their genotype One example of incomplete penetrance is a type of eye tumor called retinoblastoma, which is due to a dominant allele Not all individuals who inherit the allele develop the tumor Furthermore, the severity of the tumor varies among those individuals who show the retinoblastoma phenotype 10 _ KAPLAN _ B I O L O G Y S U B J E C T T E S T 21 E Sex-linked traits, such as hemophilia and color-blindness, are found on the X chromosome In humans, females have two X chromosomes and males have only one As a result recessive genes that are carried on the X chromosome will produce the recessive phenotypes whenever they occur in males, since no dominant allele is present to mask them The recessive phenotype will thus be much more frequently found in males Choice A is incorrect because the definition of sex-linked traits is that they are located on the sex chromosomes, typically the X chromosome Choice B is incorrect because sex-linked traits that cause disease or some other deleterious condition are usually recessive The normal trait will be a dominant allele Other sex-linked traits that not cause disease will have both dominant and recessive alleles Choice C is incorrect Sex-linked traits can be found in genetic bottlenecks if one of the founders had a sex-linked trait but are not necessarily always found in genetic bottlenecks Choice D is incorrect as sex-linked traits have obviously not been selected out of the population as we still have cases of hemophilia and color blindness 22 C For unicellular organisms, cell division is a means of reproduction, while for multicellular organisms, it is a method of growth, development, and replacement of worn-out cells Choice A is incorrect because cell division is a process by which a cell doubles its organelles and cytoplasm Choice B is incorrect because during cell division, a cell replicates its DNA, then divides in two Choice D is incorrect because cell division can follow two different courses: mitosis and meiosis 23 E In this dihybrid problem, a doubly recessive individual is crossed with an individual of unknown genotype This is known as a test cross The white bar eyed fly is a homozygous recessive, wwBB and can only produce one type of gamete: wB Looking at the offspring, there are both recessive and dominant traits present for each loci This means that there must be both recessive alleles (w and B) and dominant alleles (w+ and B+) in the unknown parent Therefore, the genotype of the unknown parent must be w+w B+B, choice E 24 B Substrate level phosphorylation occurs when ATP synthesis is directly coupled with theta degradation of glucose without the participation of an intermediate molecule such as NAD+ Degradation of one glucose molecule yields a net of ATP from glycolysis and ATP for each turn of the citric acid cycle Thus a total of ATP are produced by substrate level phosphorylation for one molecule of glucose For two molecules, it would be ATP 25 C If 15% are guanine, then another 15% must be cytosine That leaves 70% to be adenine and thymine One half of the 70% is adenine (35%) and the other half is thymine (35%) 26 B Salivary glands secrete saliva which contains salivary amylase which hydrolyzes complex carbohydrates into maltose Amylase is an enzyme, not a hormone KAPLAN _ 11 B I O L O G Y S U B J E C T T E S T Choice A is incorrect because the pituitary gland secretes a number of hormones including ACTH, TSH, and FSH Choice C is incorrect because the hypothalamus produces several hormones, including GnRH, oxytocin and vasopressin Choice D is incorrect because the heart secretes atrial natriuretic hormone which is involved in osmoregulation and blood pressure regulation Choice E is incorrect because the kidney secretes renin, which is involved in the regulation of aldosterone secretion, and erythropoietin, which stimulates the bone marrow to produce red blood cells 27 B A quick and dirty method for analyzing pedigrees states that if a trait shows up in every generation and shows no gender skewing, then it is probably an autosomal dominant trait Choice A is incorrect: If a trait skips generations and does not show gender skewing, it is probably an autosomal recessive Choice C is incorrect: Traits not typically show up mainly in females because they have two copies of the X chromosome and can therefore usually mask any deleterious genes they may inherit Choice D is incorrect: If a trait shows up typically in males it is probably a recessive allele on the X chromosome It doesn't show up in females very often because they typically have another X to mask it Choice E is incorrect: If a trait is always masked, it is probably a recessive trait although it would not be masked when it is homozygous 28 A An indeterminate cleavage is one that results in cells that maintain the ability to develop into a complete organism Choice B is incorrect because determinate cleavage results in cells whose future differentiation pathways are determined at an early developmental stage Choice C is incorrect because blastulation begins when the morula develops a fluid-filled cavity called the blastocoel, which by the fourth day becomes a hollow sphere of cells called the blastula Choice D is incorrect Once implanted in the uterus, cell migrations transform the single cell layer of the blastula into a three-layered structure called a gastrula 29 C An insertion or deletion of single nucleotide in the cell's DNA will cause a corresponding insertion or deletion in the mRNA Since mRNA is "read" by the ribosome three nucleotides at a time (3 nucleotides = a codon), an addition or deletion will result in the shift in the codon reading frame, hence the term frameshift mutation For example, if the DNA had the sequence 5'-CAT CAT CAT-3', and an Adenine were inserted, the DNA would now read 5'-CAA ATC ATC ATC-3' a very jumbled message The mRNA will be similarly effected (assuming the mutation is in a coding region, i.e exon), and every codon downstream of the mutation will be different Every amino acid being joined to the polypeptide downstream of the mutation will be incorrect, and the resulting protein will be completely dysfunctional Thymine dimers, choice A, result from UV radiation cross linking adjacent thymines When the cells enzymes attempt to repair the damage, there is the possibility that DNA polymerase will replace the thymines with an incorrect nucleotide, resulting in a point mutation So, thymine dimers are a possible cause of point mutations, not frameshift mutations A point mutation is when a nucleotide is replaced by an incorrect nucleotide There are three possible outcomes of a point mutation: 1) silent mutation: the codon that results codes for the same amino acid, so the mutation has no effect, or is "silent." This is because the genetic code is degenerate 2) missense mutation: the resulting codon codes for a 12 _ KAPLAN _ B I O L O G Y S U B J E C T T E S T different amino acid (e.g sickle cell anemia) 3) nonsense mutation: the resulting codon is a stop codon, and translation is terminated prematurely 30 A Agglutinins are the antibodies that recognize the different blood types, and are so called because the antibodies cause agglutination or clumping of blood Agglutinogens are the antigens that determine blood type The agglutinogen is found on the surface of red blood cells, and there are two types involved as discussed in question #20 If a person has the A agglutinogen they will make agglutinins to type B (anti-B) A type B person has the B agglutinogen and makes anti-A A type AB person has both agglutinogens, so makes no agglutinins (otherwise that person will coagulate their own blood) Type O blood has neither the A or B agglutinogen on the surface of the RBCs, but has agglutinins to both type A and type B Rh factor (named after the creature it was first studied in-the rhesus monkey) is another RBC agglutinogen and is completely independent of the ABO types Type A Surface Antigen A A + A A A A Red Blood Cell 31 A antibody Agglutinated RBCs A Chromosomes go from single-stranded to double-stranded when they replicate This occurs during the synthesis (S) phase of interphase 32 B Primary structure is the unique sequence of amino acids Tertiary structure involves interactions between various kinds of side chains of amino acids Quaternary structure involves the interaction of two or more polypeptides Secondary structure is the repetitious twisting or folding of the polypeptide backbone; including both α helices and β pleated sheets 33 A Myelin, produced by glial cells, allows axons to conduct impulses faster The myelin acts as an insulator, preventing ions from passing through the axon membrane Ions can only permeate through channels located in small gaps in the sheath, called nodes of Ranvier The action potential "jumps" from node to node, making saltatory conduction much faster than conduction through a non-insulated neuron Choices B and C are both achieved by the Na+/K+ pump, not myelin Choice D is incorrect because the action potential is initiated by a stimulus that causes depolarization of the axon hillock Choice E is incorrect because it is the voltage regulated ion channels that determine the threshold of a neuron 34 A The gametes that can form from an AABbCc mouse are: ABC, ABc, AbC, and Abc Therefore the correct answer is four Alternatively, using the formula 2n, where n = # of heterozygous genes, n = 2, and 22 = KAPLAN _ 13 B I O L O G Y S U B J E C T T E S T 35 C Active transport is defined as the use of energy to move a substance across a membrane against a concentration gradient 36 C All of the cells have genetic material with the exception of the erythrocyte, a biconcave disk-shaped cell that contains hemoglobin and has no nucleus 37 C Continuous muscle contraction utilizes all the available oxygen, and causes the muscle fiber to depend on anaerobic respiration for energy NAD+ must be regenerated for glycolysis to continue in the absence of O2 This is accomplished by reducing pyruvate into lactic acid and only produces two ATP per glucose 38 D Prokaryotes are unicellular organisms with a simple cell structure They have an outer cell membrane but does not contain any membrane-bound organelles There is no true nucleus; the genetic material consists of a single circular molecule of DNA concentrated in an area of the cell called the nucleoid region They have a cell wall, a cell membrane, cytoplasm, ribosomes (different from those found in eukaryotes), and sometimes flagella Eukaryotes are bounded by cell membranes and contain cytoplasm Cytoplasm contains organelles suspended in a semifluid medium called the cytosol The genetic material consists of linear strands of DNA organized into chromosomes and located within a membraneenclosed organelle called the nucleus 39 B Mitochondria are the sites of aerobic respiration within the cell and hence the suppliers of energy Each mitochondrion is bound by an outer and an inner phospholipid bilayer membrane The outer membrane is smooth and acts as a sieve, allowing molecules through on the basis of size The area between the inner and outer membranes is known as the intermembrane space The inner membrane has many convolutions called cristae and a high protein content that includes the proteins of the electron transport chain The area bounded by the inner membrane is known as the mitochondrial matrix and is the site of many of the reactions in cell respiration Mitochondria are different from the other organelles in that they are semiautonomous; that is, they contain their own circular DNA and ribosomes, which enables them to produce some of their own proteins and to self-replicate by binary fission 40 C The Hardy-Weinberg law states that gene ratios and allelic frequencies remain constant through the generations in a nonevolving population Four criteria must be met for this to occur: Random mating; a large population; no migration into or out of the population; and a lack of mutation If all four of these are met, the gene frequencies will remain constant Anytime all four of these are not met, the gene frequencies will change and evolution may occur 14 _ KAPLAN ... _ B I O L O G Y S U B J E C T T E S T Biology Subject Test Which of the following is in a different chemical category than the others? A B C D... B I O L O G Y S U B J E C T T E S T BIOLOGY SUBJECT TEST ANSWER KEY C C 17 B 25 C 33 A B 10 B 18 E 26 B 34 A B 11 C 19 A 27 B 35 C B 12 E 20... 13 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 18 PGAL A is considered the prime end product of photosynthesis