Chapter 16

Question 1

Management of plant disease depends on whether the disease is biotic or abiotic.

Answer 1

True

Question 2

The life cycle of a fungus can involve only one type of spore.

Answer 2

False

Question 3

Mycelium is a symptom of fungal disease.

Answer 3

True

Question 4

Scab is more likely to be a problem in dry, cool areas.

Answer 4

False

Question 5

Smut can overwinter in soil, plant debris, and seed.

Answer 5

True

Question 6

Most fungal agents that cause postharvest diseases are introduced to the affected seed after harvest.

Answer 6

False

Question 7

Bacterial wilt of alfalfa is less an issue today because resistant varieties.

Answer 7

True

Question 8

Plant pathogenic viruses are generally composed of DNA enclosed in a protein case.

Answer 8

False

Question 9

Viruses can enter the plant through the stomata.

Answer 9

False

Question 10

Fungi can transmit viruses to a plant.

Answer 10

True

Question 11

A method to control viral diseases is the use of pesticides.

Answer 11

False

Question 12

Insects that damage plants all have mouthparts that pierce.

Answer 12

False

Question 13

Many bactericides are copper-based.

Answer 13

True

Question 14

Contact insecticides, once absorbed by the insect, attack the nervous and respiratory system.

Answer 14

True

Question 15

UG99 stem rust has the potential to threaten 20% of the world’s food supply.

Answer 15

True

Question 16

The visual response by the plant to the pathogen is”

A. a symptom
B. a disease
C. an injury
D. an infection

Answer 16

A. a symptom

Question 17

Which of the following is NOT an abiotic disease factor?

A. parasitic plant
B. water deprivation
C. soil acidity
D. herbicide

Answer 17

A. parasitic plant

Question 18

Which of the following organisms reproduces by spores?

A. bacterium
B. virus
C. fungus
D. nematode

Answer 18

C. fungus

Question 19

Rust diseases are caused by which group of fungi?

A. sclertinomycetes
B. basidiomycetes
C. fusariomycetes
D. pythiomycetes

Answer 19

B. basidiomycetes

Question 20

Stem rust can have up to how many different spore stages?

A. two
B. three
C. five
D. seven

Answer 20

C. five

Question 21

Damping off affects which growth stage?

A. seedling
B. flowering
C. fruiting
D. senescence

Answer 21

A. seedling

Question 22

The disease associated with the Salem witch trials is

A. scab
B. rust
C. blast
D. ergot

Answer 22

D. ergot

Question 23

Leaf spots due to bacteria tend to be:

A. round
B. angular
C. mosaic
D. linear

Answer 23

B. angular

Question 24

Bacterial wilts occur when the bacteria invade the:

A. flowers
B. leaves
C. fruit
D. vascular system

Answer 24

D. vascular system

Question 25

Common and halo blight affect which crop species? A. corn B. small grains C. sugar beets D. beans

Answer 25

D. beans

Question 26

Vein clearing is a symptom common in: A. viral diseases B. bacterial diseases C. plant parasitic diseases D. fungal diseases

Answer 26

A. viral diseases

Question 27

Which plant family does tobacco mosaic virus primarily infect? A. rose family B. potato family C. grass family D. legume family

Answer 27

B. potato family

Question 28

Aster yellows is caused by which group of organisms? A. fungi B. bacteria C. viruses D. mycoplasma-like organisms

Answer 28

D. mycoplasma-like organisms

Question 29

Nematodes are a type of: A. insect B. roundworm C. fungi D. bacteria

Answer 29

B. roundworm

Question 30

The best strategy for nematode control would be: A. removal of plant debris B. seed treatments C. fungicides D. crop rotation

Answer 30

D. crop rotation

Question 31

The soybean cyst nematode causes damage by: A. necrosis B. clogging phloem C. feeding on roots D. defoliating leaves

Answer 31

C. feeding on roots

Question 32

The corn earworm feeds on what part of the corn? A. roots B. blades C. stems D. kernels

Answer 32

D. kernels

Question 33

A potential biocontrol being evaluated for use on soybean aphid is which of the following? A. Bacillus thuringiensis B. Binodoxys communis C. Pyrausta nubilalis D. Leptinotarsa decimilneata

Answer 33

B. Binodoxys communis