I. Draw and label an example of a symptom syndrome for a hypothetical disease. DO NOT USE A ROOT ROT. Include in your drawing the primary symptom and two secondary symptoms (8 pts)
a. Differentiate between primary and secondary symptoms (4 pts).
b. Give a definition of each symptom that you indicated (6 pts).
c. What physiological function does this hypothetical disease impair? (2 pts)
d. Name your disease. Be realistic. (2 pts)
II. Give three characteristics that distinguish the water mold fungi (Oomycetes) from the True fungi. (6 pts)
III. Each plant virus genome is composed of at least three genes. Name the three genes and give the function of the protein coded for by each of these genes. (6 pts)
a. How do viruses move from cell to cell? (2 pts)
b. How do they move long distances within in the plant? (2 pts)
c. What is the end result of this long distance movement? (2 pts)
IV. Matching. Place the letter from the left-hand column in the correct blanks in the right hand column. There can be more than one correct answer per trait. (14 pts)
V. Below are five drawings of structures of plant pathogens. On the drawings, letters have been placed next to specific structures. In the blanks, give the name of the labeled structure and answer the questions related to the structures (30 pts).
L. Is the organism in Fig. 1 a member of the order Tylenchida or Dorylaimida? What were the reasons for your selection?
M. In what season of the year are the spores in the fruiting body in Fig. 2 formed?
N. To what class of fungi does the structure in Fig.3 belong?
V. Matching. Below are tools or characteristics that plant disease diagnosticians routinely use to help determine the pathogen group associated with the disease. Place the letter from the left column in the correct blank(s) of the right hand column. There can be more than one correct answer per pathogen group (10 pts)
|A. water soaking
B. selective media
C. Baermann funnel
F. electron microscope
VI. What would the distribution of disease look like in a field...
if the pathogen were windborne from the west (2 pts)
b. if the pathogen were soilborne (2 pts)
c. if the pathogen were seedborne and spread of disease occurred (2 pts).