WBCS(Main)-2008 Zoology Paper-II Question Paper

                                                WEST   BENGAL   CIVIL  SERVICE 

                                                           EXAMINATION - 2008

                                                                Zoology Paper-II


Time Allowed-3 Hours                                                                                        Full Marks-100 


                                                                      Group - A 

                                                        (Answer any three questions.)


1.  (a)  Describe the ultra structures of Golgi bodies.      8

     (b)  Write briefly how Golgi bodies are formed.      4

     (c)  Enumerate principal functions of the Golgi bodies.      5

     (d)  Name three enzymes found in outer membrane, inner membrane and the matrix of mitochondria. Comment on their functions.     3  


2.  (a)  Name and describe the molecular changes exhibited by ejaculated sperms favouring fertilization.     8

     (b)  Give diagram and explain the structure of zona proteins.     5

     (c)  Write short notes on :

           (i) Role qf yolk in cleavage      31/2

           (ii) Ultra structure of sperm    31/2


3.  (a)   Explain with a diagram the nucleosome model.     6

     (b)  How from Klinefelter and Turner karyotypes and their corresponding sexual phenotypes, you may conclude that Y chromosome determines maleness in human ?      4

     (c)  What is specialised transduction ?  Explain with example.     5

     (d)  State the role of RNA polymerase-II in transcription.      5


4.  Write notes on any five :

    (a)   Southern blot technique

    (b)   ‘C value paradox

    (c)   X ist gene

    (d)  YAC  

    (e)  Sex-influenced traits

    (f)  Shine-Dalgarno Sequence

    (g)  Okazaki fragments.          4x5


5.  (a)  Explain Hardy-Weinburg equilibrium.      2

    (b)  Cystic fibrosis is an autosomal recessive disorder, in certain population in North Europe, this disorder show an incidence of 1/2500.  What proportion of individuals in this population are carriers for this disease ?   Justify your calculations.     6

    (c)  What do you mean by “stabilizing selection” and “directional selection” ?     4  

    (d)   Point out the phyletic gradualistic trends in the equine evolution.     8



                                                     Answer any two questions.


6.  Write notes on any five :

    (a)  Zoological nomenclature

    (b)  Lectotype and syntype

    (c)  ‘OTU‘ 

    (d)  \alpha, \beta, \gamma-taxonomy

    (e)  Category

    (f)  Cryptic species

    (g)  Biological species concept.     4x5


7.  (a)  What is “All-or-Nothing” principle ?     2

     (b)   Explain all the factors that determine the resting membrane potential of nerve fibres.     4

     (c)  What are the successive stages of the action potential which we find in a nerve fibre, during transmission of signals ?  Explain with diagram.    8

     (d)  What is gluconeogenesis ?  Schematically describe this pathway.     6


8.  (a)  Discuss briefly the primary, secondary, tertiary  and quarternary structure of protein.     8

     (b)  What is allosteric modulation.     2

     (c)  What do you know about competitive, noncompetitive and uncompetitive inhibition of enzyme ?    6

     (d)  What is xerophthalmia and beriberi.    4