INASMO - 2022 IBO TEAM SELECTION 2nd ROUND EXAM REGULATIONS 1. Exam will be held on Saturday, February 19th, Saturday at 9:30 AM in Stirling Colleges, which is found in each city. 2. Students who show at least 60% success in the second round will be eligible for the third round. 3. There are 50 questions. Students will have 150 minutes working time for the question paper. 4. Do not open this booklet until told to do so by the invigilator. 5. This is a multiple-choice question paper. Each question is followed by answers marked A, B, C and D 6. In these tests there is only one correct answer to each question. If more than one alternative is marked, that answer will automatically be counted wrong. 7. SCORING RULES: Correct answer : + 2 points Wrong answer : − 0.25 point No answer : no point 8. The exam results will be announced by the school administration at the school where you had the second-round exam. 9. 3rd Round Exam will be held in April 30, 2022. (Could be rearranged according to the Educational Syllabus). 1 INTERNATIONAL BIOLOGY OLYMPIAD – 2nd ROUND 10. Exam topics are the following topics: The Chemistry of Life (12 points) The Chemical Context of Life, Water and Life, Carbon and the Molecular Diversity of Life, the Structure and Function of Large Biological Molecules The Cell (20 points) A Tour of the Cell, Membrane Structure and Function, An Introduction to Metabolism, Cellular Respiration and Fermentation, Photosynthesis, Cell Communication, The Cell Cycle Genetics (40 points) Meiosis and Sexual Life Cycles, Mendel and the Gene Idea, The Chromosomal Basis of Inheritance, The Molecular Basis of Inheritance, Gene Expression: From Gene to Protein, DNA Tools and Biotechnology Plant Form and Function (28 points) Vascular Plant Structure, Growth, and Development, Resource Acquisition and Transport in Vascular Plants, Soil and Plant Nutrition, Angiosperm Reproduction and Biotechnology, Plant Responses to Internal and External Signals 2 INTERNATIONAL BIOLOGY OLYMPIAD – 2nd ROUND 1. The ionic bond of sodium chloride is formed when 5. Which of the following take place as an ice cube cools a drink? a. Chlorine gains a proton from sodium b. Sodium gains an electron from chlorine c. Sodium and chlorine share a pair of electrons d. Chlorine gains an electron from sodium a. Molecular collusions in the drink increases b. Kinetic energy in the drink increases as energy flow to the water molecules from ice cube c. Evaporation of the water in the drink decreases d. The electronegativity of water molecules increases 2. An element “X” has 7 electrons in its outer shell. Which is true about element “X”? 6. And a human genome, the first of which took over 10 years to sequence, could be completed at today’s pace in day or less. The number of genomes that have been fully sequenced has exploded. All these progresses are result of a new field which use of computer software and other computational tools that can handle and analyze these large data sets. What is that biology related interdisplinary field called? a. It is stable and chemically non-reactive b. Its atom contains 7 protons c. It can accept an electron to acquire noble gas configuration d. It can lose an electron to become stable 3. One of the buffers that contribute to pH stability in human blood is carbonic acid (H2CO3). Carbonic acid is a weak acid that dissociates into a bicarbonate ion (HCO3-) and a hydrogen ion (H+). Thus, H2CO3 HCO3- + H+ . If the pH of blood drops, one would expect a. Genomics b. Bioinformatics c. Molecular computing science d. Genetics a. A decrease in the concentration of H2CO3 and an increase in the concentration of HCO3b. The concentration hydroxide ion (OH-) to increase c. The concentration of bicarbonate ion to increase d. The HCO3- to act as a base and remove excess H+ with the formation of H2CO3 7. A cell cycle consists of: 4. Which of the following contains nitrogen in addition to carbon, oxygen and hydrogen? 8. How do cells at the completion of meiosis compare with the diploid cell from which they were derived? a. A steroid such as testosterone b. A polysaccharide such as cellulose c. An amino acid such as glycine d. An alcohol such as ethanol a. They have twice the amount of cytoplasm and half the amount of DNA. b. They have half the number of chromosomes and half the amount of DNA. c. They have the same number of chromosomes and half the amount of DNA. d. They have the same number of chromosomes and the same amount of DNA. a. mitosis and meiosis. b. G1, the S phase, and G2. c. prophase, metaphase, anaphase, and telophase. d. interphase and mitosis. 3 INTERNATIONAL BIOLOGY OLYMPIAD – 2nd ROUND 9. During the light-dependent reactions of photosynthesis (photophosphorylation), light energy is converted to chemical potential energy through the process of chemiosmosis in the chloroplasts. Which of the following statements about this process is FALSE? a. During photophosphorylation, the chloroplast stroma becomes more acidic than the interior of the thylakoid membranes. b. Protons diffuse through protein channels which are ATP synthetase molecules. c. ATP is synthesized from ADP and Pi on the stroma side of the thylakoid membranes in the chloroplast. d. During photophosphorylation, water ionizes to form H+ and OH- ions, yielding an electron to Photosystem II. 10. Which of the following statements about the Calvin cycle are FALSE? a. The first stable product of the cycle is 3phosphoglycerate. b. The reducing power of NADPH is used to reduce 3phosphoglycerate to glyceraldehyde 3-phosphate (PGAL). c. The carboxylation of the 5-carbon sugar ribulose 1,5 bisphosphate (RuBP) is catalyzed by the rubisco enzyme (ribulose bisphosphate carboxylase/oxygenase). d. Two molecules of ATP are synthesized for each "turn" of the cycle. 12. Which of the following evaluations is correct about regulation processes given in the diagram given above? a. Regulation process A is about post-translational modification of enzymes but regulation process of B is about regulation of gene expression b. Regulation process A is about regulation of enzyme activity but regulation process of B is about regulation of enzyme production c. Regulation process A is about pre-translational modification of enzymes but regulation process of B is about regulation of translation d. Regulation process B is about regulation of enzyme activity but regulation process of A is about regulation of enzyme production 11. A soluble red dye is injected into the phloem of a young plant about half-way up the stem. At the same time a yellow dye is injected into the xylem at the same height along the stem. Which statement best explains where the two dyes will be found one day later? a. The tip of the plant (farthest from the soil) will contain only red dye; the tip of the root (deepest into the soil) only yellow dye. b. The tip of the plant will contain only yellow dye; the tip of the root only red dye. c. The tip of the plant will contain both red and yellow dye; the tip of the root only red dye. d. The tip of the plant will contain only red dye; the tip of the root both red and yellow dye. 4 INTERNATIONAL BIOLOGY OLYMPIAD – 2nd ROUND 13. A …..I….. operon is one that is usually on; binding of a …..II….. to the operator shuts off transcription. An example for this operon is …..III….. operon. But an …..IV….. operon is one that is usually off; a molecule called an …..V….. inactivates the repressor and turns on transcription. An example for this operon is …..VI….. operon. Which of the followings is correct for information about operons given above? I A Repre ssible B Repre ssible C Induci ble D Repre ssible II Repr essor Indu cible Indu cer Repr essor III Lacto se Repre ssor Lacto se Trypt ophan IV Induci ble Induc er Repre ssible Induci ble V Induc er Trypt ophan Repre ssor Induc er Some genetic materials are given below. I. Plasmids II. Transposons III. Viruses IV. Insertion sequences (IS) 16. Which of the following evaluations is correct? a. All of them are mobile genetic elements and all can be used as vector for gene transfer b. All of them are mobile genetic elements and all can be used as vector for gene transfer except IS because there is no ORI region in IS for replication after transfer of gene c. All of them are mobile genetic elements but only plasmids and transposons can be used as vector for gene transfer d. All of them are mobile genetic elements but any of them can be used as vector for gene transfer because of their low capacity of gene VI Trypt ophan Lacto se Trypt ophan Lacto se 17. The polymerase chain reaction, PCR, can produce many copies of a specific target segment of DNA. PCR is a three-step cycle brings about a chain reaction that produces an exponentially growing population of identical DNA molecules. Which of the following is correct about PCR? 14. Chemical modifications to histones and DNA of chromatin influence both chromatin structure and gene expression. Which of the following modifications results in loosening of chromatin and initiation of transcription accordingly? a. First step is cooling for denaturation, second step is heating for annealing and the last step is replication by using heat resistant polymerase enzyme b. First step is cooling for denaturation, second step is replication by using heat resistant polymerase enzyme and the last step is heating for annealing c. First step is replication by using heat resistant polymerase enzyme, second step is cooling for denaturation and the last step is heating for annealing d. First step is heating for denaturation, second step is cooling for annealing and the last step is replication by using heat resistant polymerase enzyme a. DNA acetylation b. DNA methylation c. Histone acetylation d. Removal of phosphate groups (dephosphorylation) next to a methylated amino acid in histone 15. Prions are slow-acting, virtually indestructible infectious proteins that cause brain diseases in mammals. How can prions propagate within infected cells or organisms? a. By using cellular mechanism, they can propagate within cells or organisms b. Ribosomes of infected cells produce prions so they propagate by this way c. Prions propagate by converting normal proteins into the prion version. d. Rough endoplasmic reticulum in infected cells produces prions so they propagate by this way 5 INTERNATIONAL BIOLOGY OLYMPIAD – 2nd ROUND 18. In most nuclear transplantation studies, only a small percentage of cloned embryos have developed normally to birth. Which of the following options is/are appropriate solution for this problem? 21.I. Mads-box genes in animals are the regulatory equivalent of Hox genes in plants. II. Homeotic genes in animals are called Hox genes. III. Homeobox genes code for a domain that allows a protein to bind to DNA and to function as a transcription regulator. IV. Modifications within humans are due to single nucleotide polymorphisms, inversions, deletions, and duplications. V. Small changes in regulatory sequences of certain genes can lead to major changes in body form. a. Epigenetic change like acetylation of histones must be reversed in the nucleus from a donor animal b. Epigenetic change like methylation of DNA must be reversed in the nucleus from a donor animal c. Epigenetic change like phosphorylation of amino acids next to a methylated amino acid in histone must be reversed in the nucleus from a donor animal d. All are correct because all kinds of epigenetic changes must be reversed in the nucleus from a donor animal Five information sentences are given above. Choose the correct options in the table below about these sentences? 19. Vertebrate genomes can produce more than one polypeptide per gene because of A B C D a. an alternative splicing of RNA transcripts b. an alternative starting points while transcription of RNAs c. an alternative starting points while replication of DNA d. usage of alternative different enzymes while transcription of RNAs I False Correct False False II Correct Correct Correct False III Correct False Correct Correct IV Correct Correct False Correct V False False Correct Correct 22. Arrange the following five events in an order that explains the bulk flow of substances in the phloem. 20. Which of the followings contribute to genome evolution? I. Water diffuses into the sieve tube elements II. Leaf cells produce sugar by photosynthesis III. Solutes are actively transported into sieve elements IV. Sugar is transported from cell to cell via the apoplast and/or symplast V. Sugar moves down the stem a. Duplication b. Rearrangement c. mutations of DNA d. All of them a. II, I, IV, III, V b. I, II, III, IV, V c. II, IV, III, I, V d. IV, II, I, III, V 23. During winter, tree sap can sometimes freeze and "cavitation" (the formation of an air pocket) may occur. Which one of the following mechanisms of sap transport would you expect to be most immediately affected by cavitation? a. symport b. pressure flow (mass flow) c. cohesion transpiration d. root pressure 6 INTERNATIONAL BIOLOGY OLYMPIAD – 2nd ROUND 24. The pressure-flow model of phloem sap transport involves _____. 28. You are growing plants hydroponically, measuring CO2 usage. The plants initially grow robustly, but soon CO2 assimilation drops. Young leaves continue to grow normally, but older leaves begin to yellow. Which of the following is the MOST likely cause for the observed changes? a. decreased hydrostatic pressure at the sugar source end as a result of reduced water potential b. increased hydrostatic pressure at the sugar source end as a result of reduced water potential c. decreased hydrostatic pressure at the sugar source end as a result of increased water potential d. increased hydrostatic pressure at the sugar source end as a result of increased water potential a. The hydroponic medium lacks magnesium. b. The plants are preparing to flower. c. The plants are mutants which overproduce gibberellins. d. The hydroponic medium lacks oxygen, causing the roots to suffocate. 25. Plants can modify their water potential by opening and closing their stomata to modulate the rate of respiration according to environmental conditions. Which environmental condition would cause the stomata to close? 29. Students are sketching diagrams of the shoot system of angiosperms for a plant anatomy class. These lists describe diagrams made by four students. Which diagram represents the shoot system incorrectly? a. Increased temperature b. High oxygen concentration c. High relative humidity d. High light levels a. Leaves, stem, fruit, flowers b. Stem, fruit, leaves, branches c. Flowers, leaves, branches, stem d. Stem, hair roots, leaves, flowers, branches 26. On a field trip, students collect a few samples to analyze back in their classroom. One student picks a blade of grass in the field and identifies it as a dicot leaf, but his partner thinks it is a monocot. Which explanation supports his partner's opinion? 30. Modified organs are part of survival strategies of plants. Which plant has a flattened, photosynthetic stem that could be mistaken for a leaf? a. The leaf displays a thin lamina. b. There is no petiole. c. The margins are serrated. d. The venation is parallel. a. Fern b. Cactus c. Potato d. Iris 27. Scientists are cataloguing slides of plant crosssections. They are interested in finding examples of secondary growth. Which example contributes to secondary growth? 31. Which one of the followings is a photosynthetic plant parasite? a. Mistletoe b. Rafflesia c. Indian pipe c. Staghorn fern a. Apical meristem, which contributes to increase in length b. Vascular cambium, which contributes to increase in thickness or girth c. Root region, which shows an increase in root hairs d. Stems, which show an increase in number of leaves 7 INTERNATIONAL BIOLOGY OLYMPIAD – 2nd ROUND 32. ………………. ensures that endosperm develops only in ovules where the egg has been fertilized: a. Fertilization c. Pollination 36. de-etiolation means: a. When a stem reaches light, the plant undergoes profound change. b. When a shoot reaches light, the plant undergoes profound change. c. When a leaf reaches light, the plant undergoes profound change. d. None of them b. Double fertilization d. Seed Development 33. The plant that provides the roots is called: a. Scion c. Stock b. Callus d. Shoot 34. Which one of the following plants is not belonged to short day plants: a. Chrysanthemums c. Soybean 37. An individual of the genotype AaBbCcDd was crossed with the one aabbccdd and the following results were obtained. b. Poinsettias d. Dandelions aBCD 42 Abcd 43 ABCd 140 abcD 145 aBcD 6 AbCd 9 ABcd 305 abCD 310 35. In cattle, the polled (hornless) condition is dominant to the horned condition. Coat colour can be red, white or roan (red with White patches). Both genes are carried on autosomes and they are not linked. A cross was carried out between a cow and a bull, both of which had the roan coat colour and both were heterozygous for the polled condition. Which of the following statements are true about the offspring from the cross, assuming that the cross was carried out several times to produce a lot of offspring? Which of the following shows the arrangement of the genes and their distance (in centimorgans)? 1. The chance of producing white polled and white horned offspring is the same. 2. The chance of producing roan polled offspring is three times that of producing roan horned. 3. There is an equal chance of producing red polled and White polled offspring. 4. Statistically there should be more roan horned offspring than any other type. 5. The chance of producing roan polled offspring is twice that of producing white polled. a. 1 & 2 b. 2 & 3 c. 3 & 4 d. 2, 3 & 5 8 INTERNATIONAL BIOLOGY OLYMPIAD – 2nd ROUND 41. Hemoglobin in the erythrocytes of adults is composed of a combination of two a-globin molecules and two bglobin molecules. Sickle-cell anemia is caused by the substitution of a single amino acid in the b-globin subunit. In 1957, Vernon M. Ingram and his colleagues investigated the amino acid sequences of normal and sickle-cell anemia hemoglobins in several short peptide chains obtained by trypsin digestion. A difference in the “fourth peptide” between both types of b-globin was found and further hydrolytic digestion of the “fourth peptides” revealed six hydrolyzed products. 38. When a dominant allele (A) is alone, it causes a brown fur color but when it is with another dominant allele which has an epistatic effect, the fur color is white. According to this, which of the following shows the true genotypes of the individuals in the family tree given above? 1 a. Aabb b. AaBb c. AaBb d. Aabb 2 AaBb aabb aaBb aabb 3 Aabb Aabb AaBb Aabb 4 AaBb aaBb Aabb aaBb # the “fourth peptide” products of normal b-globin were (amino acid residues are abbreviated by the following letters: V=valine, H= histidine, L= leucine, T= threonine, P= proline, E= glutamic acid and K= lysine): V—H V—H—L V—H—L—T T—P—E T—P—E—E—K E—K 5 aabb aabb Aabb aabb # the “fourth peptide” products of b-globin of sickle cell anemia were V—H V—H—L V—H—L—T T—P—V T—P—V—E—K E—K 39. Which statement regarding the amount of genomic DNA per cell (M) during the cell cycle is correct? a. M [G1] = M [meiosis prophase II] b. M [meiosis prophase II] = 2 x M [meiosis prophase I] c. M [G1] = M [G2] d. M [G2 after mitosis] < M [G2 after meiosis] From these results, how many amino acids is the “fourth peptide” composed of and what was the substituted position of amino acid residue counting from the N-terminus? From the following, choose the one statement which is most appropriate. Assume that this fourth peptide contains only one molecule of T (threonine). 40. The strand of DNA molecule isolated from E. coli bacteria has sequence 5’ GТАGCCТАCCCАТАGG 3’. Assume that an mRNA is transcribed from the corresponding double-stranded DNA, the template strand being complementary to the strand isolated. What is the sequence of this mRNA? a. It was composed of 8 amino acids and the 6th amino acid was substituted. b. It was composed of 8 amino acids and the 3rd amino acid was substituted. c. It was composed of 7 amino acids and the 6th amino acid was substituted. d. It was composed of 7 amino acids and the 3rd amino acid was substituted. a. 3’ – CAUCGGAUGGGUAUCC – 5’. b. 5’ – GUAGCCUACCCAUAGG – 3’. c. 5’ – GGAUACCCAUCCGAUG – 3’. d. 5’ – CACAGAUACCCAGAUG – 3’. 9 INTERNATIONAL BIOLOGY OLYMPIAD – 2nd ROUND 42. Karyotypes represent a display of the chromosomes present in eukaryotic cells. The following diagram shows a mutated human female karyotype. 44. Which of the following diagrams represents anaphase I of meiosis? a. I b. II c. IV d. V 45. The following question refers to this figure of a simple metabolic pathway: Which chromosomal mutation could be observed from the diagram? If A, B, and C are all required for growth, a strain that is mutant for the gene-encoding enzyme A would be able to grow on which of the following media? a. Deletion b. Duplication c. Translocation d. Insertion a. minimal medium b. minimal medium supplemented with nutrient A only c. minimal medium supplemented with nutrient B only d. minimal medium supplemented with nutrient C only 43. A DNA molecule has 160 base pairs and 20 percent of adenine nucleotides. How many cytosine nucleotides are present in this molecule? 46. A plot of reaction rate (velocity) against temperature for an enzyme indicates little activity at 0°C and 45°C, with peak activity at 35°C. The most reasonable explanation for the low velocity at 0°C is that a. 20 cytosine nucleotides. b. 60 cytosine nucleotides. c. 32 cytosine nucleotides. d. 48 cytosine nucleotides. a. the hydrogen bonds that define the enzyme's active site are unstable b. the substrate becomes an allosteric regulator c. there is too little activation energy available d. the co-factors required by the enzyme system lack the thermal energy required to activate the enzyme 10 INTERNATIONAL BIOLOGY OLYMPIAD – 2nd ROUND 47. A researcher made an interesting observation about a protein made by the rough endoplasmic reticulum and eventually used to build a cell’s plasma membrane. The protein in the membrane was actually slightly different from the protein made in the ER. The protein was probably altered in the 50. Green olives may be preserved in brine, which is a 20-30% salt solution. How does this method prevent contamination by microorganisms? a. Bacterial cell walls are shrivelled up by salt, causing the cell to burst. b. High salt concentrations lower the pH, thus inhibiting the process of glycolysis. c. High salt concentrations raise the pH, thus inhibiting the process of glycolysis. d. Bacteria can't survive in a hypertonic solution because they lose water a. Golgi apparatus b. smooth endoplasmic reticulum c. mitochondrion d. nucleus 48. Imagine two solutions separated by a selectively permeable membrane that allows water to pass, but not sucrose or glucose. The membrane separates a 0.2molar sucrose solution from a 0.2-molar glucose solution. With time, how will the solutions change? a. Nothing happens because the two solutions are isotonic to one another. b. Water enters the sucrose solution because the sucrose molecule is a disaccharide and thus larger than the monosaccharide glucose. c. Water leaves the sucrose solution because the sucrose molecule is a disaccharide and thus larger than the monosaccharide glucose. d. The sucrose solution is hypertonic and will gain water because the total mass of sucrose is greater than that of glucose. 49. In glycolysis, the glucose splits into two 3-carbon compounds: glyceraldehyde-3-phosphate and 1,3diphosphoglyceric acid. Which of the following statements is true? a. Only one of these compounds is used, which explains the low efficiency of energy retrieval of cell respiration. b. Glyceraldehyde-3-phosphate and 1,3diphosphoglyceric acid are interconvertible. c. One of the compounds goes through the Krebs cycle and one becomes lactate. d. All of the carbons in glyceraldehyde-3-phosphate are immediately converted to carbon dioxide. 11 INTERNATIONAL BIOLOGY OLYMPIAD – 2nd ROUND