Fonte: gare di altri paesi/India/biologia/INBO2019-Question.pdf · Apri PDF · apri PDF p.1
Cluster: Meccanica
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Problema 1
INDIAN NATIONAL BIOLOGY OLYMPIAD- 2019 INSTRUCTIONS
The question paper is divided into Sections A and B. All answers should be written in the answer sheet booklet only which will be collected at the end of the examination. The question paper need not be submitted to the examiner.
Section A Before starting, ensure that you have received a copy of this Question Paper containing a total of 39 pages (39 sides on 20 sheets). Section A consists of 26 questions carrying 1 point each. All 26 questions are of multiple choice type, with only one correct answer for each question. Mark the correct answer with „✔‟ in the answer sheet provided. The correct way of marking is shown below. Use a pen to mark your answer.
Q. No. a b c d
✔
Each wrong answer will have negative marking as indicated in the scoring key. Section B Section B consists of 30 questions with a total of 74 points. The points for the questions in Section B vary depending on the number of answers and the complexity of the question. These points have been indicated along with the question. Contradictory answers will not be considered for marking.
SCORING KEY NO. OF CORRECT ANSWERS: X NO. OF INCORRECT ANSWERS: Y
SCORE INBO (THEORY): SECTION A: 3X – Y
SECTION B: 3X
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INDIAN NATIONAL BIOLOGY OLYMPIAD – 2019 SECTION A CELL BIOLOGY (7 points)
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(1 point) When human genome was sequenced, the annotated number of genes was found to be ~20,000. Based on complexity of humans, however, it was expected that there would be more than 100,000 genes. Which of the following statements would explain this discrepancy? a. The current methods of sequencing are inefficient to identify the large number of genes. b. Enhanced somatic recombination in humans takes place to generate more number of genes. c. Large number of genes in humans undergo alternative splicing to generate proteome diversity. d. Fewer genes through frame shift translation can generate more number of proteins.
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(1 point) Molecular chaperones promote folding of proteins using energy from ATP. In the presence of ATP, chaperones assume an open conformation. This exposes pockets (P) in the chaperone which bind and enclose regions of nascent polypeptides that might promote aggregation. Imagine that life evolved in benzene instead of water, leading to the same set of amino acids and proteins as we have in biology now. In such a hypothetical scenario, which of the following amino acids is most likely to be found lining P of chaperones? a. Isoleucine b. Glutamine c. Arginine d. Cysteine
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(1 point) Consider a diploid organism with 2n value of 4. How many chromosomes and DNA molecules respectively are present in the G1 and G2 phases of a somatic cell of this organism? (consider only nuclear DNA) a. G1: 4 and 4; G2: 4 and 4 b. G1: 4 and 4; G2: 4 and 8 c. G1: 4 and 4; G2: 8 and 4 d. G1: 4 and 4; G2: 8 and 8
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(1 point) Chloroplasts, according to the theory of endosymbiosis, represent originally free-living prokaryotes that were taken inside eukaryotic cells and lost their ability to exist independently. Which of the following is least likely to be encoded by the chloroplast genome based on this theory? a. Chloroplast DNA Polymerase b. Chloroplast RNA Polymerase c. Chloroplast ribosomal subunits d. Chloroplast tRNA
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(1 point) Of the sunlight that reaches the surface of the earth, biological processes mostly make use of light of wavelength between 400nm to 700nm. Which of the following transitions, critical for life, will occur in the molecules absorbing photons in this range of wavelengths? a. Vibrational transitions b. Rotational transitions c. Electronic transitions d. Nuclear transitions
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(1 point) ATPases are protein complexes which are found on different membranes of the cell. The following diagrams show the structure of two major types of ATPases, the P-type ATPase and F-type ATPase.
P-type ATPase F-type ATPase
Which of the following statement/s regarding the ATPases is/are true?
i. ATPases are always involved in the synthesis of ATP. ii. The P-type ATPase is formed from a single polypeptide.
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iii. The F-type ATPase is a multiprotein complex. iv. Both the above types of ATPases are directly involved in the active transport of ions. a. i only b. ii and iii c. i and iv d. iv only
- (1 point) A scientist was analysing a particular DNA sequence in humans and its relation to a disease. Which of the following data is most supportive of the scientist‟s hypothesis that the particular sequence is NOT related to the disease?
Percent of diseased individuals having the sequence Percent of non-diseased individuals having the sequence A 48% 52% B 65% 35% C 90% 10% D 20% 80%
PLANT SCIENCES (5 points)
- (1 point) The graph below represents the annual temperature, rainfall and sunshine at a tropical site in India.
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(Top panel: The three lines indicate the maximum, mean and minimum temperature.
Bottom panel: The grey bars indicate amount of rainfall and the curve indicates the sunshine hours.) Trees growing in this region flush (put out) new leaves during the months of March and April. This is the hottest and driest time of the year. Which of the following could be the reasons for this phenomenon?
i. New leaves avoid insect herbivory which is accompanied by the rains. ii. New leaves with highest photosynthesis efficiency would be able to maximise the sunshine hours. iii. New leaves lose least water and hence are more efficient during the dry period. iv. New leaves are more tolerant than mature leaves to abiotic stresses like high temperature. a. i and ii only b. ii and iv only c. iii and iv only d. i, ii, iii and iv
- (1point) Observe the experimental set-up shown here carefully and answer the following question.
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Which of the following hypotheses is the experimental set-up designed to test? a. The amount of water required by a plant increases with increase in the rate of evaporation of water through transpiration. b. The process of transpiration can generate enough pressure to pull water up the column. c. The increase in the atmospheric pressure increases the rate of transpiration in plants. d. The process of water transport though stem requires an unbroken column of liquid.
- (1 point) In the coleoptile-bending assay developed by Went in 1928, a coleoptile is decapitated and kept for a few hours. A block of agar soaked in a known concentration of plant hormone, auxin, is then kept on one side of the decapitated coleoptile. The entire set-up is kept in the dark throughout the procedure. After a few hours, the curvature of the tip is measured. The pictures below show the schematic of the four steps of the assay.
The graph below shows the effect of concentration of auxin on the bending or curvature.
This graph could be used to estimate concentration of auxin in a sample by measuring the angle of curvature or bending due to the block soaked in the sample. Angle of curvature (o) 0 5 10 15 20 0 0.1 0.2 0.3 0.4 0.5 Auxin concentration (mg.L-1)
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Answer the questions 10 and 11 based on the above experiment.
Which of the following cases could lead to the overestimation of auxin in the sample? a. If the agar block with unknown auxin is loaded without any incubation after decapitation. b. If agar block is kept exactly on the top of the coleoptile instead of on one side. c. If the size of the agar block is reduced to half. d. If the duration between the application of agar block and measuring of bending is reduced.
- (1 point) How will the graph look if there is reduction in the sensitivity of the coleoptile to the auxin?
a. A b. B c. C d. D
- (1 point) Photosynthesis results in the production of glucose in plants which
Topic: Conservation of Energy, Rotational Dynamics, Oscillations & Waves Metodi: Energy Conservation Method, Conservation Laws, Torque & Angular Momentum Analysis, Free-Body Diagram Competenze: Physical Reasoning, Mathematical Modeling, Diagrammatic Reasoning Fonte: Testo (PDF) — p.1