S1253 Microbiology (SS12BMI)

November, 1980

  1. Write and essay on the chemoautotrophic and methylotrophic bacteria.

  2. Write briefly on three of the following:

    (i) The clostridia

    (ii) The Bacilli

    (iii) Blue-green bacteria

    (iv) Bdellovibrio

    (v) Pseudomonads.

  3. (a) "The ciliated protozoans have achieved the pinnacle of unicellular organisation". Discuss this statement with reference to a typical member of this group of microorganisms.

    (b) Select which of the following statements are false, and indicate in some detail, the reasons for your choice.:

    (i) Proteins are usually good antigens and many have more than one antigenic determinant capable of eliciting an immune response.

    (ii) The fungi and procaryotic organisms displaying autotrophic nutrition and are commonly found in the soil and decaying organic matter.

    (iii) Viruses are very small non-cellular life forms that reproduce by parasitising host cells at the genetic level.

    (iv) The immunoglobulin, IgG, is able to cross the placenta, appears relatively early during a primary immune response and has a higher valency for binding antigen than the other immunoglobulins.

    (v) Recovery from infectious disease often involves the co-operative functions of both free immunoglobulins and also cellular components of the lymphoid system.

  4. Write notes on any three (3) of the following:

    (a) The assembly of virus particles.

    (b) The general functions of lymphocytes during the immune response.

    (c) Actively acquired immunity.

    (d) Bacterial exotoxins and human disease.

    (e) The secondary immune response.

  5. Write a general account of conjugation in bacteria. Discuss the significance (to bacteria and man) of conjugation.

  6. Write briefly on three of the following:

    (a) Male-specific viruses.

    (b) The `restriction' of DNA by bacteria.

    (c) Lichens.

    (d) Nitrogen-fixing bacteria.

  7. (a) Describe the major differences between the Embden Meyerhof pathway and the hexose monophosphate pathway.

    (b) Two organisms (A and B) when grown anaerobically with glucose as the energy source, produce ethanol, acetate and formate as end products. A produces these in the ratio 1:1:2 respectively, B in the ratio 0.5:2:1.

    (i ) Would you expect any additional end products to those above for either A or B?
    Give a reasoned answer.

    (ii) Outline the pathway for each organism to account for the observed end product distribution.

  8. Write notes on four of the following:

    (i ) Stickland reaction.

    (ii ) Metabolism of acetate by butyric bacteria.

    (iii) Photosynthesis in the purple and green bacteria.

    (iv ) Estimation of molar growth yields, YATP from chemostat studies.

    (v ) Energy metabolism in the chemoautotrophs.

Author: Dr Bharat Patel <>
HTML'd by Troy Baalham
[Created: 01 Apr 1996]
[Modified: 20 May 1996]