NEMATOLOGY 100 MID-TERM EXAM -- 1 1/2 HOURS OCTOBER 28, 1992

   1.  (20 points) You are provided with nematodes extracted from soil used
       in an experiment to determine the effect of certain species on potato.
       Place an adult female plant-parasitic nematode of any species in the 
       Order Tylenchida on a microscope slide.
       Heat-kill the nematode with gentle heat before applying a coverslip.
       Place the slide on the compound microscope.                          
       Call the instructor for examination of your nematode.  If there is more 
       than one nematode present in the microscope field, indicate the specimen 
       you wish to have examined.  Do not ask or expect the instructor to make 
       the selection.  Only the nematode that you indicate initially will be 
       considered.  You should not have to leave your bench position.
       Grading:
         adult female plant-parasite (Tylenchida), good condition - 20 pts
         plant-parasite not in Tylenchida                            8 pts
         non-parasite, good condition -                              4 pts
         points off for damage, distortion, dry slides, etc.
   2.  (15 points) Describe the structure and location of various chemosensory 
       structures of nematodes in the Tylenchida.  What is their apparent 
       function.  Discuss hypotheses of integration of signals from these 
       sensilla in orientation of the nematodes.
   3.  (15 points) Provide a generalized drawing of an adult female nematode 
       that is diovarial, amphidelphic, with evidence that functional males are
       present in the population and that fertilization has occurred.  
       Indicate a postcorpus does not overlap the intestine.
       Label the features of the esophageal and stoma regions and of the 
       reproductive and digestive tracts.
   4.  (13 points) Describe the parasitism of the lance nematode, Hoplolaimus columbus
        on cotton and soybeans.  What tissues are affected?  What is the
       overall impact on plant growth?
   5.  (12 points) The sting nematode, Belonolaimus longicaudatus, has been  
       detected this year in golf courses in Southern California.  Provide the
       following general and diagnostic characters of this nematode by circling
       the appropriate choice:
       (i) Order: a) Tylenchida                                      
                  b) Rhabditida
                  c) Diplogasterida
                  d) Dorylaimida
      (ii)
Esophagus type : a) tylenchid - butting
                            b) tylenchid - overlapping,
                            c) dorylaimid
     (iii) Number of ovaries (female): a) one
                                       b) two
                                       c) more than two
      (iv) Known vector of a plant virus? a) no
                                          b) yes
       (v) Adult female feeding habit: a)
migratory ectoparasite,
                                       b) migratory endoparasite
                                       c) sedentary endoparasite
      (vi) a) males common (probably reproducing sexually)
           b) males uncommon (probably parthenogenic)

   6.  (15 points) What are the soil and climatic conditions in which the    
       burrowing nematode,
Radopholus similis is especially damaging to  
       citrus in Florida?  Describe the nature and effect of the damage.

   7.  (10 points) List 5 diagnostic characteristics of organisms in the
       Phylum Nematoda.
 
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