S1253 Microbiology (SS12BMI)
Supplementary Examination

February, 1981

  1. Write briefly on three of the following :

    (i) Mycorrihzas.

    (ii) The use of microorganisms in industry.

    (iii) Bacterial cell walls.

    (iv) The Clostridia.

  2. Write an essay on the photosynthetic bacteria (phototrophs).

  3. Write briefly on two of the following :

    (i) Plasmids.

    (ii) Genetic transduction.

    (iii) Transformation.

  4. Discuss the metabolic (nutritional) and structural criteria used to categorise the procaryotes.

  5. (a) Write notes on three (3) of the following :

    (i) Amoeboid protozoans

    (ii) Nutrition of the fungi

    (iii) The eclipse phase of a viral infection

    (iv) Actively acquired immunity.

    (b) Select which of the following statements are false and give reasons for your choice.

    (i) Viruses are very small life forms that parasitise the cells of eucaryotic organisms at the genetic level.

    (ii) The fungi are eucaryotic organisms displaying heterotrophic nutrition and often grow aerobically.

    (iii) The immunoglobulic, IgM, is unable to cross the placenta, appears relatively early during a primary immune response and has a higher valency for binding antigen than other immunoglobulins.

    (iv) The principal function of lymphocytes is to produce immunoglobulins.

    (v) Viruses contain nucleic acid as their genetic material which may be either DNA or RNA, and may be in either the single stranded or double stranded form.

    (vi) Immunoglobulins are protein molecules composed of four identical polypeptide chains held together by disulphide bonds, and have one antigen binding site associated with each polypeptide chain.

  6. Write an account of the difference between bacterial exotoxins and endotoxins. Explain how the pathogenic effects of tetanus in humans differ from those caused by Salmonella typhi.

  7. (a) Describe the major differences between the pentose phosphate pathway and the Entner-Doudoroff pathway.

    (b) An organism when grown anaerobically with glucose as the energy source, produces butan-1, 3-diol.

    (i) Outline a pathway to account for the observed end product.

    (ii) Would you expect any additional end products? Give a reasoned answer.

  8. Write notes on four of the following :

    (i) Stickland reaction

    (ii) Metabolism of acetate by butyric acid bacteria

    (iii) Photosynthesis in the purple and green bacteria

    (iv) Aeroduric anaerobes of the genus Biffidobacterium

    (v) Cytochrome systems present in gram negative bacteria.

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