CSIR NET LIfe Sciences Paper 3 June 2010

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  1. Answer the following
    1. What is scientific method?
    2. Why distilled water has 6-PH?
    3. A DNA molecule has 100 bp added in 5 ml of water. Calculate its concentration in mm. If molecular wt for an average nucleotide is 300 Dalton.
    4. Calculate the height of human body is y = height, x = age; equation is y = mx + c; m = 6.2, x = 15, c = 40
  2. Answer the following
    1. Give the botanical name and family of following: Crocus, Coir, Flax, Vanilla & Saffron
    2. How development of embryo in cruciferie differs from asteroid type?
    3. Vavilov centre of origin of Radish, Seasame, Peanut & Olive
  3. Answer the following
    1. Why virulence is lost on sub culturing.
    2. What are all the other mechanism apart from nitrogen fixation by which microorganisms help the plant to obtain nitrogen?
    3. In which form plants take sulphur. How it is chemically metabolized so that it becomes part of amino acids?
  4. Answer the following
    1. Differentiate between 1i transcript and mature m-RNA. Give processing of 1i transcript.
    2. What is the importance of non-coding region in post-transcriptional changes?
  5. Answer the following
    1. Why ovulation does not occur during pregnancy?
    2. Glucose is filtered through Glomerulus in Bowman՚s capsule. Then why it is not excreted through urine.
    3. Why in terrestrial organisms mode of excretion is through urea or uric acid but not through ammonia although former is energy consuming process.
  6. Answer the following
    1. Differentiate between Acoelom & pseudocoelom. Give the example of each.
    2. What is coelom? Differentiate between proteostome and deuterostome.
  7. Answer the following
    1. What is water potential? Give its equation and explain.
    2. Describe the events occurring in the two cell when one is placed in hypotonic solution and another is placed in hypertonic solution.
  8. Answer the following
    1. Write various defense mechanisms bacteria use to evade host specific Immune response.
    2. Difference between Immune response to Extra cellular pathogens and Intracellular pathogens.
  9. Answer the following
    1. Picogram of a plasmid DNA was used to transform E. Coli by electroporation and 700 colonies were obtained. Calculate transformation frequency of the competent cells of E. Coli used in experiment.
    2. A certain strain of E. Coli could not be infected by many lambda phages tested. Give at least 2 possible reasons for this.
    3. I wish to clone a repetitive sequence of DNA into a plasmid vector. What mutation in the E. Coli genome would ensure successful maintenance of this DNA sequence in E. Coli.
  10. Answer the following
    1. A researcher wishes to increase sucrose biosynthesis in plants through genetic engineering. Suggest a method.
    2. What strategies can be used to engineer plants to produce biodegradable plastics?
    3. What are the four segments of DNA that typically comprise the plasmid genome?
  11. Answer the following
    1. Differentiate asymmetric hybrids and Cybrids.
    2. Differentiate Gametoclonal variation and Somaclonal variation.
    3. Differentiate electro fusion and electroportion.
    4. Differentiate Androgenic and Gynogenic haploids.
  12. Answer the following
    1. What is the major difference between endo cytic and extracellular receptor?
    2. Hydrophilic and hydrophobic signaling molecules
    3. What are 2nd messengers? Name 5 in Eukaryotic signal transduction?
  13. Answer the following
    1. Define resolution of microscope.
    2. Name the organism from which green fluorescence protein was originally discovered.
    3. Fluorescence ionphone.
  14. Answer the following
    1. A student accidently mixed 2 solutions to form a new solution containing 2 proteins of similar densities (SOH = 1.3 gm/cc) but different mol. Weight (60KD & 190 KD) It also contained 2 types of sub cellular organelles not very different in size but differing in densities (SOH = 1.11 gm/cc and SOH = 1.23 gm/cc respectively) . Assuming that student has access only to ultra centrifugation. What purification scheme should be planned to separate the four.
    2. How will you find out if the 2 proteins are linked to each other by disulphide bridges using any technique that you know?
  15. Why do cyanobacteria dominate over green algae in eutrophic aquatic ecosystem? There is algal bloom in pond (coastal region) . If piscivorous fishes are introduced, how is algal bloom in control? Explain mechanism and ecological process.
  16. What are the similarities and differences between abzymes and ribozymes?
  17. Answer the following
    1. The phosphorylation of glucose always takes place in the presence of ATP. Why is it so? In liver cell, the concentration of glucose is 5mM each. What do you think will happen in absence of ATP under these conditions?
    2. Why most of the biological reactions are kept away from equilibrium?
  18. Answer the following
    1. The inactivation of x chromosomes in mammals is random. Design an experiment to show this.
    2. Retinoblastosis is caused due to mutation in both the alleles of rb gene. Can this tumor be prevented if concentration of the tumor suppressor gene is increased in all the human cells?
    3. Influenza virus has a cell surface protein that is activated by acidic pH and helps in fusion of influenza virus membrane with last cell membrane for virus entry into the cell. A primitive treatment to this infection involves sleeping in the horse stable. Now it has been shown that horse stable has high concentration of NH3. Diagrammatically explain this phenomenon
  19. Answer the following
    1. Intensive shrimp culture will effect the coastal ecosystem of India. Explain.
    2. Different zones in marine ecosystem.
  20. Answer the following
    1. Citric acid cycle does not involve the utilization of O2, but TCA does not take place in the absence of O2. Why is it so?
    2. Enoyl CoA isomerase deficiency will effect which metabolism? Butter or olive oil metabolism?
    3. How is GTP synthesized in TCA converted to cellular pool of ATP?
  21. Answer the following
    1. In an E. Coli strain, a mutation in E lac repressor has taken place as a result of which lactose is not able to bind to the repressor. If this mutant and a wild type E. Coli are grown in a medium containing lactose and glucose, What will be the growth curves of both these strains?
    2. A mutant phage is not able to lysogenise in E. Coli. Where would you map the mutations?
  22. What are base analogs? How are they useful in?
    1. Gene mapping
    2. Gene mutations
  23. How would you determine RNA concentration? Give 3 methods. Which is the most sensitive method?