MIDTRM98.HLP Rev 11/98
Nematology 100 MID-TERM EXAM 11/04/98 90 minutes
1. (25 points)
You are provided with nematodes that represent a composite of samples
from landcscape vegertation around campus.
a. Place an adult female plant-parasitic nematode of any species on a
microscope slide.
Kill the nematode with gentle heat.
Apply a coverslip.
Seal the edge of the coverslip with fingernail polish to prevent the
slide from drying out.
Place the slide on the compound microscope and adjust the microscope
to provide Köhler illumination.
b. Indicate on your exam sheet the Class and Order of your nematode.
c. Draw and label the component parts of the stylet and esophagus for
this type of nematode (either from your specimen, or from your
knowledge of anatomy and morphology, or both).
d. 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.
Grading:
adult female plant-parasite, good condition - 15 pts
non-parasite, good condition - 8 pts
correct designation of Class and Order - 2 pts
correct drawing and identification of stylet/esophagus - 8 pts
points off for damage, distortion, dry slides, etc.
2. (15 points)
Describe, with the aid of drawings, the components and various
configurations of the female reproductive system nematodes.
Briefly describe the function of each structure.
3. (10 points) Describe the geographic location and soil conditions that
favor the sting nematode, Belonolaimus longicaudatus. What crops are
damaged?
(10 points)
4. Describe the life cycle of Paratylenchus hamatus (the pin nematode),
indicate survival/persistent stages and discuss the nature and importance
of males.
5. a) Sketch the anterior portion of 3 nematode genera which are vectors of
viruses.
b) Identify each genus drawn.
c) List the particle type and virus classification for each genus.
d) Discuss the location of the virus in the nematode and persistence or
transmission of the virus across various stages of the nematode life
cycle.
e) (i) Name a nematode vectored virus disease in California.
(ii) Name the vector.
(iii) Name the plant host.
(iv) What group is the virus classified in?
(10 points)
6. Describe the feeding process in Paratrichodorus minor (the stubby root
nematode).
7. (20 points)
Provide the following information for each of the nematodes
listed.
Answer by using the appropriate letter.
(i) Order: a) Tylenchida,
b) Rhabditida,
c) Diplogastrida,
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) Provide a recognized common name.
Paratylenchus neoamblycephalus
8. (10 points)
Which genera of nematodes transmit NEPO viruses? Where are
the particles carried in each genus?
9. (10 points)
Briefly describe the excretory systems of a tylenchid and a
dorylaimid nematode.