India 2009 — inbo2009-Q.pdf

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Problema 1

CELL BIOLOGY (7)

1 INDIAN NATIONAL BIOLOGY OLYMPIAD – 2009 SECTION A

CELL BIOLOGY (7)

1. (1 point) Which one of the following is made up of only one type of macromolecule? a. Virus b. Plasmid c. Ribosome d. Nucleosome

2. (1 point) A scientist introduced bacterial plasmids into bakers’ yeast. However, the cells lost these plasmids over a period of time. Which of the following needs to be inserted into the bacterial plasmid to overcome this problem? a. Centromere b. Yeast origin of replication c. Telomere d. Bacterial origin of replication

3. (1 point) A red blood corpuscle (RBC) was kept in a solution and treated so that it became inside - out. What will be the polarity of the phospholipid bilayer in this cell?

Hydrophobic end a. b. c. d. Hydrophilic end Phospholipid

2 4. (1 point) Some vitamins need to be supplied regularly in our daily diets while others may be supplied intermittently. Examples of these two types, respectively, are: a. Vit C and Vit D b. Vit A and Vit B6 c. Vit D and Vit E d. Vit B6 and Vit B12

5. (1 point) Which of the following pathways depicts the generalized glycolytic scheme most accurately?

Pyruvate Glucose a b c d e f g h d. e c. b Pyruvate Glucose a c d f g h e b. b Pyruvate Glucose a c d f g h e a. b Pyruvate Glucose a c d f g h

3 6. (1 point) Membrane compositions of three cell types are tabulated below.

Membrane Composition (%) Cell Type Protein Phospholipid Sterol Rat liver cell 46 30 20 Maize leaf cell 40 35 8 E. coli 74 26 0

The % composition of inner mitochondrial membrane is likely to be: a. 40:30:20 b. 42:33:9 c. 43:33:15 d. 76:24:0

7. (1 point) Which of the following facts supports the hypothesis that “viruses are not the fore-runners of cellular organisms but are derived from them”? a. Viruses use the same genetic code as the cellular organisms. b. Viral proteins have the same basic amino acids as cellular organisms. c. Viruses need the cellular machinery for replication. d. Enzymes essential for viral replication are identical to those needed for cellular replication.

PLANT SCIENCES (8)

8. (1 point) Which of the following graphs correctly depicts the evolution of various vascular plant species in evolutionary time scale?

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a. Number of species 400 300 200 100 0 Age (millions of years) 400 300 200 100 0 Age (millions of years) 400 300 200 100 0 Age (millions of years) 400 300 200 100 0 Age (millions of years) : Pteridophytes

: Gymnosperms

: Angiosperms

: Plant progenitors b. Number of species c. Number of species d. Number of species

5 9. (1 point) Photosynthetic features of four plants P, Q, R and S are depicted in the graphs below.

These plant species belong to: a. P: C3 plant Q: C4 plant R: CAM plant S: shade plant b. P: C4 plant Q: C3 plant R: C4 plant

S: C3 plant c. P: C4 plant Q: sun plant R: C3 plant

S: CAM plant d. P: C3 plant Q: C4 plant R: C3 plant

S: C4 plant

10. (1 point) The nutritional pathway shown below represents:

a. photo-litho-autotroph. b. photo-chemo-heterotroph. c. photo-organo-autotroph. d. chemo-organo-autotroph. Concentration of CO2 within the intercellular space S R P Q Uptake of CO2 Uptake of CO2 Leaf temperature chlorophyll energy succinate ATP fumarate H (CH2O)n CO2

6 11. (1 point) On a warm summer’s day, the transpiration pull is the main force that drives water from root parenchyma into the root xylem. The table shows values of $\text{psip}$ (pressure potential) and $\text{psis}$ (solute potential) in root xylem and root parenchyma, in kPa. In which of the alternatives a – d would transpiration pull cause water to move from root parenchyma into the root xylem?

Root parenchyma Root xylem

$\text{psip}$ $\text{psis}$ $\text{psip}$ $\text{psis}$ a 200 –190 –200 5 b –200 220 65 –5 c 200 –220 65 –5 d 200 –220 –65 –5

12. (1 point) Calvin and colleagues determined the pathway of carbohydrate synthesis in plants by studying the incorporation of radioactive carbon dioxide into biological compounds. Suppose that photosynthesis is proceeding at a steady pace in a typical experiment with the lights on, and carbon dioxide is being combined with ribulose-bisphosphate (RuBP) to produce 3- phosphoglycerate (3PG). Then suddenly the source of carbon dioxide is eliminated. What changes in the concentrations of 3PG and RuBP would occur? a. 3PG levels rise, RuBP levels fall. b. 3PG levels fall, RuBP levels rise. c. 3PG levels rise, RuBP levels rise. d. 3PG levels rise, RuBP levels stay the same.

13. (1 point) Thermal imaging is a technique used to detect mutant varieties of plants that overproduce abscisic acid (ABA). Such plants are warmer than the surrounding plants. This can be explained as: a. an elevated level of ABA increases the rate of metabolism thereby producing more heat.

7 b. overproduction of ABA is mostly observed in C4 plants which require high optimum temperatures for photosynthesis. c. increased levels of ABA in the cell sap will increase the rate of transpiration causing drying of the plant. This in turn will cause such a plant to be warmer than the surrounding plants. d. increased ABA will not allow the stomata to open completely and thereby reduce evaporative cooling of the plant.

14. (1 point) While working on the root cap of Rorippa amphibian, some anatomists noticed presence of a few specialized cells with watery cytoplasm having freely movable starch grains. On further investigation, similar cells were found in the root cap of several other plants. The most likely function of these cells is: a. to give mechanical strength to the root cap. b. to provide ready source of energy required for rapid cell divisions at the root tip. c. to exert pressure along the physically lower side of the cell to ensure positive geotropism. d. to help replacing the worn out cells of the root cap.

15. (1 point) Auxin at an appropriate concentration can induce cell elongation in certain plant organs. However, tissues respond differently to different concentrations of auxin. Which graph best represents the IAA response of shoot and root?

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a.

b.

c.

d.

9 ANIMAL SCIENCES (4)

16. (1 point) An enzyme arginase (that converts arginine to ornithine and urea ) extracted from an amphibian kidney shows following biochemical parameters:

P Q Vmax 5.1 x 10-4 mM urea/ min 8.3x10-4 mM urea/min Specific Activity 9.1 x 10-5 units 1.3 x 10-4 units

P and Q, respectively are: a. hydrated and desiccated environment of the animal. b. fresh water and saline environment. c. desiccated and deoxygenated environment. d. adult and tadpole stage.

17. (1 point) Oxytocin shows following four consequences in the human body: i) Hypertension ii) Uterine contraction iii) Milk ejection iv) Anti-diuresis

These results are due to effect on: a. smooth muscle and membrane permeability. b. striated muscle and membrane depolarization. c. smooth and striated muscles. d. voluntary and involuntary muscles.

18. (1 point) Relative rates of red blood cell production in the bone marrow of different bones at different ages are shown in the graph. P, Q and R are likely to be, respectively:

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a. vertebra, rib and tibia. b. femur, carpal and rib. c. tibia, fibula and femur. d. radius, sternum and carpal.

19. (1 point) Characteristic features of different blood vessels in the body are shown. P, Q and R represent:

a. P: Total area

Q: Velocity

R: Blood pressure b. P: Blood pressure Q: Velocity

R Total area c. P: Velocity

Q: Total area R: Blood pressure d.

Topic: Conservation of Energy, Thermodynamics, Special Relativity Metodi: Energy Conservation Method, Conservation Laws, First Law of Thermodynamics, Thermodynamic Cycle Analysis Competenze: Physical Reasoning, Mathematical Modeling Fonte: Testo (PDF) — p.1