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Unformatted text preview: Hyperplasia is an abnormal increase in the number of cells. Hypertrophy and hyperplasia usually results in galls or tumors forming. Crown gall Agrobacterium tumefaciens and Corn Smut Ustilago zeae are two pathogens that cause hypertrophy and hyperplasia 5. (1 pt) Define the term sign. A sign is a part of the pathogen visible on host tissue. 6. (2 pts) Give two examples of a sign and define both terms. Sclerotia are a compact mass of hyphae surrounded by a darkened shell. Perithecia are a type reproductive structure. 7. (2 pts) Define the term halo. What other symptom are haloes generally associated with on plants? A halo is a circular ring of discoloration and is commonly found with necrotic symptoms. 8. (1 pt) What is a mosaic? A mosaic is an alternating pattern of light and dark green tissue on a plant normally caused by a virus...
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This note was uploaded on 03/22/2008 for the course PP 315 taught by Professor Shew during the Spring '08 term at N.C. State.
- Spring '08