GS; Ch 1 Part C:

4. generally microscopic, unsegmented roundworms that live free in moist soil, water, or decaying matter, or as parasites in plants and animals.
6. a disease increase. Or a widespread and severe outbreak of a disease.
8. tiny sacs (pycnidia or perithecia) produced by fungi that release reproductive spores (conidia or ascospores).
11. the vegetative part of a fungus consisting of threadlike hyphae.
12. small, typically multicell organisms. Some attack plants and cause diseases such as rusts, smuts, mildews, wilts, and leaf spots.
15. a plant variety that is unaffected by a certain pesticide or that is able to limit infection, reproduction or damage by a certain pest.
17. an organism capable of transmitting a pathogen.
18. a condition in which a plant differs from a normal (healthy) plant in appearance, structure, or function.
20. the study of plant disease.
21. microscopic, single-celled organisms that reproduce by division; many genera and species are beneficial; while others cause plant diseases such as wilts, soft rots, and leaf blights or spots.
22. how a plant responds to plant disease, such as chlorosis, stunting, wilt, spots, lesions, or root rot.
24. death of plant tissue; usually characterized by browning or drying.

1. a disease that is caused by unfavorable growing conditions and cannot be transmitted from plant to plant.
2. an organism or agent capable of causing infectious disease.
3. lacking the ability to resist disease or attack by a particular pathogen.
5. evidence of the actual pathogen such as mycelium, sclerotia, or fruiting bodies. Some require the aid of a hand lens or microscope to be visible.
7. an organism (such as an insect, fungus, bacterium, or nematode) that obtains its food from another organism.
9. a disease caused by a pathogen that multiplies and can be transmitted from plant to plant.
10. a disease that is present every year but generally does not cause significant damage.
13. a submicroscopic piece of DNA or RNA capable of causing discoloration, stunted or unusual growth, and poor development of plants. They are only capable of reproducing only in living animal and plant cells.
14. formerly called mycoplasmas or MLOs, these bacteria like organisms lack cell walls. They are usually transmitted by insects or plant propagation and cause “yellows” and “witches’ broom” disease symptoms.
16. any plant or animal that is invaded by a parasite.
19. a dormant or reproductive structure of fungi, analogous to the seed of green plants.
23. microscopic organisms such as fungi, bacteria, viruses, and nematodes.