Unit 1: Introduction to Plant Nematology - Practice Quiz

PTH214 — Fundamentals Of Nematology 60 Questions
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1 Who is widely known as the father of nematology?

History of phytonematology Easy
A. Robert Koch
B. Louis Pasteur
C. Gregor Mendel
D. Nathan A. Cobb

2 Which scientist reported root-knot symptoms on cucumber plants in England in 1855?

History of phytonematology Easy
A. N. A. Cobb
B. J. N. Sasser
C. H. Schacht
D. M. J. Berkeley

3 The term phytonematology refers to the study of which organisms?

History of phytonematology Easy
A. Plant-associated nematodes
B. Plant-pathogenic bacteria
C. Crop-feeding insects and their natural predators
D. Soil-borne fungi

4 In which habitat are plant-parasitic nematodes most commonly found?

Habitat and diversity Easy
A. Deep ocean water far from vegetation
B. Upper layers of the atmosphere
C. Dry surfaces of rocks
D. Soil around plant roots

5 Which structure is commonly used by plant-parasitic nematodes to puncture plant cells?

Habitat and diversity Easy
A. Mandible
B. Stylet
C. Antenna
D. Proboscis

6 Nematodes are best described as which type of animal?

Habitat and diversity Easy
A. Microscopic animals that always possess a hard external shell
B. Segmented flatworms
C. Joint-legged arthropods
D. Unsegmented roundworms

7 Who made an early report of root-knot nematodes on tea in India in 1901?

Evolution of nematode research in India and globally Easy
A. N. A. Cobb
B. H. Schacht
C. C. A. Barber
D. M. J. Berkeley

8 Which technological development greatly improved the early study of nematodes?

Evolution of nematode research in India and globally Easy
A. Light microscopy
B. Satellite imaging
C. Automated harvesting machinery used in large farms
D. Steam cultivation

9 Modern molecular methods identify nematodes mainly by examining their what?

Evolution of nematode research in India and globally Easy
A. Soil texture
B. DNA
C. Leaf color
D. Daily movement

10 Why are plant-parasitic nematodes economically important?

Economic importance of nematodes Easy
A. They replace all fertilizers by releasing large amounts of nutrients
B. They increase rainfall over crop fields
C. They improve the color of every harvested product
D. They damage crops and reduce farm income

11 Which nematode is well known for producing galls on plant roots?

Economic importance of nematodes Easy
A. Root-knot nematode
B. Cyst nematode
C. Lesion nematode
D. Stem nematode

12 Which practice can help reduce economic losses caused by plant-parasitic nematodes?

Economic importance of nematodes Easy
A. Increasing weed growth
B. Planting the same susceptible crop continuously without monitoring
C. Reusing infested soil everywhere
D. Growing resistant varieties

13 How do root-feeding nematodes commonly reduce crop yield?

Impact on crop yield Easy
A. By increasing seed size before harvest
B. By damaging roots and limiting uptake
C. By converting every root into a nitrogen-fixing structure
D. By improving water absorption during drought

14 Which above-ground symptom commonly occurs when nematodes severely damage crop roots?

Impact on crop yield Easy
A. Stunting
B. Permanent resistance to all soil-borne pathogens
C. Faster flowering
D. Larger leaves

15 Nematode damage in a field often appears in which pattern?

Impact on crop yield Easy
A. Perfect circles
B. A single straight line across every type of soil
C. Irregular patches
D. Uniform rows

16 How can nematode infection affect the market quality of root and tuber crops?

Impact on quality Easy
A. By causing lesions and deformities
B. By producing uniform shapes
C. By creating an additional protective skin around every harvested root
D. By improving storage life

17 Which quality characteristic may decline when nematodes attack harvested plant parts?

Impact on quality Easy
A. Length of daylight
B. Appearance
C. Rainfall
D. Soil depth

18 Nematode-created wounds may reduce crop quality because they can provide entry points for what?

Impact on quality Easy
A. Other pathogens
B. Sunlight
C. Mineral fertilizers
D. Beneficial insects that pollinate flowers throughout the season

19 What is the main purpose of plant quarantine in relation to nematodes?

Impact on international trade Easy
A. To prevent pest movement between regions
B. To improve the flavor of imported crops
C. To guarantee that every shipment contains the same crop variety
D. To increase the weight of exported produce

20 Which traded material is most likely to carry plant-parasitic nematodes to a new country?

Impact on international trade Easy
A. Clean glass containers
B. Sealed metal tools
C. Infested planting material
D. Processed plastic packaging manufactured without soil contact

21 A historian finds an eighteenth-century report describing worms recovered from abnormal wheat seeds called "ear-cockles." Which scientist is most closely associated with this early observation?

History of phytonematology Medium
A. Hermann Schacht
B. Miles Joseph Berkeley
C. John Needham
D. Nathan A. Cobb

22 Which sequence correctly orders these developments from earliest to most recent?

History of phytonematology Medium
A. Berkeley's root-knot report → Needham's wheat observation → Cobb's systematic studies
B. Cobb's systematic studies → Needham's wheat observation → Berkeley's root-knot report
C. Needham's wheat observation → Berkeley's root-knot report → Cobb's systematic studies
D. Needham's wheat observation → Cobb's systematic studies → Berkeley's root-knot report

23 A survey detects nematodes in agricultural soil, freshwater sediment, marine sediment, and plant tissue. What is the best conclusion from these findings?

Habitat and diversity Medium
A. Nematodes survive only where crops are cultivated
B. All nematodes detected are plant parasites
C. Nematodes occupy highly diverse ecological habitats
D. Marine nematodes originated recently from farmland

24 A nematode remains outside the root but inserts its stylet into epidermal cells to feed. How should its parasitic habit be classified?

Habitat and diversity Medium
A. Migratory endoparasite
B. Migratory ectoparasite
C. Sedentary ectoparasite
D. Sedentary endoparasite

25 Two soil samples contain equal total numbers of nematodes. Sample X contains bacterivores, fungivores, predators, omnivores, and plant parasites, while Sample Y is dominated by one plant-parasitic species. Which interpretation is most appropriate?

Habitat and diversity Medium
A. Both samples have identical community structure
B. Sample X has greater trophic diversity
C. Neither sample contains a nematode community
D. Sample Y has greater trophic diversity

26 A historical account describes a 1901 report of root-knot nematodes damaging tea in southern India. Why is this report important to Indian nematology?

Evolution of nematode research in India and globally Medium
A. It established the first global nematode quarantine agreement
B. It demonstrated that all tea decline was nematode-induced
C. It was an early documented plant-nematode report from India
D. It introduced electron microscopy into Indian laboratories

27 A laboratory replaces identification based only on body measurements with an approach combining morphology, host response, and DNA markers. Which research trend does this represent?

Evolution of nematode research in India and globally Medium
A. Restriction of research to field observations
B. Replacement of taxonomy by crop breeding
C. Return to symptom-based diagnosis alone
D. Development toward integrative nematode diagnostics

28 Why did the establishment of specialized nematology divisions, professional societies, and coordinated surveys accelerate nematode research in India?

Evolution of nematode research in India and globally Medium
A. They transferred plant protection entirely to quarantine agencies
B. They organized expertise, training, and regional data collection
C. They eliminated the need for field-based crop experiments
D. They made all nematode species easy to identify visually

29 A field has a plant-parasitic nematode population below the economic threshold. Which decision is generally most appropriate?

Economic importance of nematodes Medium
A. Apply the most expensive nematicide immediately
B. Destroy the crop before symptoms become visible
C. Assume the population cannot increase during the season
D. Monitor the population and avoid unnecessary treatment

30 A nematode causes moderate root injury but also creates infection sites for a soil-borne fungus. Which estimate best represents its economic importance?

Economic importance of nematodes Medium
A. Visible shoot symptoms without production losses
B. Combined direct damage and disease-complex losses
C. Direct root damage without secondary disease losses
D. Control expenditure without any crop value

31 A treatment costs $120 per hectare and is expected to prevent a crop loss worth $300 per hectare. Ignoring other costs, what is the economically rational decision?

Economic importance of nematodes Medium
A. Reject the treatment because the expected net benefit is $120
B. Apply the treatment because the expected net benefit is $180
C. Apply the treatment because the expected net benefit is $300
D. Reject the treatment because the expected net benefit is negative

32 A nematode-free plot yields 8 tonnes per hectare, while an infested plot yields 6 tonnes per hectare under otherwise similar conditions. What is the estimated percentage yield loss?

Impact on crop yield Medium
A.
B.
C.
D.

33 Two fields contain the same initial root-knot nematode density. One is planted with a susceptible cultivar and the other with a resistant cultivar. Which outcome is most likely?

Impact on crop yield Medium
A. The resistant cultivar will support more reproduction and greater yield loss
B. Both cultivars will show equal reproduction and equal yield loss
C. The susceptible cultivar will support more reproduction and greater yield loss
D. Neither cultivar will be affected because initial densities are equal

34 A crop infested early in the season suffers greater yield loss than a crop infested shortly before harvest. What best explains this difference?

Impact on crop yield Medium
A. Late infection always kills nematodes before they reproduce
B. Late infection permanently increases the crop's genetic resistance
C. Early infection disrupts growth during more developmental stages
D. Early infection prevents all other pathogens from entering roots

35 A potato crop produces nearly normal total biomass, but tubers have lesions and surface blemishes caused by nematodes. What is the most likely economic consequence?

Impact on quality Medium
A. Increased market grade because biomass is unchanged
B. Reduced market grade despite limited biomass loss
C. No economic loss unless every tuber is destroyed
D. Higher seed value because lesions indicate maturity

36 A seed-gall nematode replaces normal wheat grains with dark galls. Which quality component is affected most directly?

Impact on quality Medium
A. Flowering duration of the processed wheat flour
B. Physical purity and acceptability of the grain lot
C. Photosynthetic rate of the harvested grain lot
D. Rooting depth of grain during warehouse storage

37 A root nematode reduces nutrient uptake in a fruit crop, producing smaller fruits with uneven ripening. Why is this classified as a quality impact?

Impact on quality Medium
A. It increases the number of export certificates
B. It lowers size uniformity and market grade
C. It changes only the soil texture around roots
D. It guarantees a longer postharvest storage life

38 An importing country requires a shipment of planting material to be certified free from a regulated nematode. What is the main purpose of this requirement?

Impact on international trade Medium
A. To ensure that all nonparasitic nematodes are removed
B. To guarantee that the crop has the highest possible yield
C. To prevent introduction and establishment of the regulated pest
D. To determine the fertilizer requirement of the importing farm

39 A quarantine nematode is detected in one consignment of seed potatoes at an international port. Which immediate action is most consistent with phytosanitary practice?

Impact on international trade Medium
A. Send the consignment directly to farms for field confirmation
B. Hold the consignment and apply the prescribed regulatory measure
C. Mix the consignment with uninfested lots to reduce prevalence
D. Release the consignment because symptoms are not yet visible

40 Why can a nematode with limited visible effects in the exporting country still cause rejection of a shipment by another country?

Impact on international trade Medium
A. Its quarantine status depends on risk to the importing country
B. Its detection proves that every item in the shipment is damaged
C. Its presence matters only when commodity prices are decreasing
D. Its trade status depends only on symptoms in the exporting country

41 Which observation most directly established that some nematodes were causal agents of plant disease rather than merely secondary inhabitants of damaged tissue?

History of phytonematology Hard
A. Their association with visible root lesions
B. Their reproduction inside infected plant tissues
C. Their repeated recovery from decaying plant organs
D. Their successful transmission causing symptoms in healthy plants

42 Why was the discovery of the wheat seed-gall nematode historically important to plant nematology?

History of phytonematology Hard
A. It demonstrated that nematodes developed only in roots
B. It proved that all nematodes required living hosts
C. It linked a microscopic animal with a seed-borne crop disease
D. It established nematodes as exclusive vectors of viruses

43 A historical account describes a nematode species by its host-associated symptoms but without microscopy, morphology, or infection tests. What is the most defensible interpretation?

History of phytonematology Hard
A. It is a provisional disease observation
B. It is evidence of obligate parasitism
C. It is proof of a virus interaction
D. It is a confirmed species record

44 A soil sample contains abundant nematodes, but only a small fraction are plant parasites. Which conclusion is most scientifically justified?

Habitat and diversity Hard
A. The crop is experiencing severe nematode damage
B. The nonparasitic forms are accidental soil contaminants
C. Most nematodes are feeding directly on crop roots
D. The community includes multiple functional feeding groups

45 Which ecological feature best explains why plant-parasitic nematode populations can remain undetected in a field despite causing later crop losses?

Habitat and diversity Hard
A. Their hosts are uniformly distributed
B. Their feeding occurs only after harvest
C. Their populations may be spatially aggregated
D. Their eggs always hatch immediately

46 A nematode is recovered from a plant but is absent from surrounding bulk soil. Which explanation is most consistent with nematode ecology?

Habitat and diversity Hard
A. It cannot complete any developmental stage
B. It may occupy a protected endophytic habitat
C. It necessarily originated from irrigation water
D. It must be a free-living bacterial feeder

47 Which development most changed modern nematode diagnosis from morphology-centered identification toward an integrative approach?

Evolution of nematode research in India and globally Hard
A. Replacing field surveys with greenhouse observations
B. Using host symptoms as the primary taxonomic character
C. Classifying species only by their geographic origin
D. Combining morphology, morphometrics, and molecular markers

48 Why did the expansion of intensive agriculture increase the strategic importance of nematology in India and worldwide?

Evolution of nematode research in India and globally Hard
A. It increased repeated cultivation of susceptible hosts
B. It eliminated nematode survival between crop cycles
C. It reduced host continuity across production systems
D. It made nematode damage independent of soil conditions

49 A research program shifts from identifying individual nematode species to studying suppressive soils, host resistance, and cropping systems. What does this shift represent?

Evolution of nematode research in India and globally Hard
A. A rejection of epidemiology in favor of morphology
B. A return from molecular biology to symptom classification
C. A replacement of field research by laboratory culture
D. A move from descriptive taxonomy toward systems-based management

50 Which research strategy would best distinguish a genuinely emerging nematode problem from improved detection of a long-established species?

Evolution of nematode research in India and globally Hard
A. Infer emergence from the first published species name
B. Compare historical samples using standardized detection methods
C. Compare damage estimates without accounting for host area
D. Use only recent symptom reports from commercial fields

51 Why can a nematode with modest average yield effects still be economically important at regional scale?

Economic importance of nematodes Hard
A. Average losses always underestimate postharvest quality
B. Regional production is unaffected by crop price
C. Small losses multiplied across extensive acreage can be substantial
D. Nematodes cause identical damage in every field

52 Which factor would most likely cause the economic threshold for nematode management to be lower in one crop than another?

Economic importance of nematodes Hard
A. The crop has high value and limited damage tolerance
B. The crop is grown in a field with greater soil depth
C. The crop tolerates root injury more effectively
D. The crop has a lower market value

53 A nematode management practice increases yield but also raises production costs and reduces marketable quality. Which measure best evaluates its economic success?

Economic importance of nematodes Hard
A. Nematode population decline alone
B. Number of nematodes killed per gram of soil
C. Gross yield increase alone
D. Net return from marketable yield

54 Two fields have the same final nematode density, but one shows greater yield loss. Which explanation is most plausible?

Impact on crop yield Hard
A. Final density always predicts loss better than initial density
B. Nematodes affect yield only through direct tissue consumption
C. The crops may differ in host susceptibility and stress exposure
D. The fields necessarily have identical damage histories

55 Why may early nematode infection reduce yield even when plants show no obvious above-ground symptoms?

Impact on crop yield Hard
A. Nematodes remain inactive until seed maturation
B. Yield formation is unrelated to root system function
C. Above-ground symptoms always precede root effects
D. Root damage can reduce water and nutrient acquisition before canopy symptoms appear

56 A resistant cultivar maintains yield in a nematode-infested field but supports a gradual increase in nematode density. What is the principal long-term concern?

Impact on crop yield Hard
A. Yield stability proves population suppression
B. The cultivar must be immune to all nematodes
C. Nematode density is irrelevant when symptoms are absent
D. The cultivar may be tolerant but not resistant

57 Which outcome best illustrates a nematode effect on crop quality rather than merely on yield quantity?

Impact on quality Hard
A. Tubers develop internal discoloration and reduced market grade
B. Fewer plants emerge per unit area
C. Root length increases without yield change
D. Field size decreases after land preparation

58 A nematode infestation causes uneven fruit size but little change in total fruit weight. Which interpretation is most appropriate?

Impact on quality Hard
A. Quality and grade losses may occur despite stable aggregate yield
B. There is no economic impact because total weight is stable
C. The symptom proves that the nematode is nonparasitic
D. The nematode has increased crop uniformity

59 Why can the detection of a regulated plant-parasitic nematode affect international trade even when the shipment shows no visible crop damage?

Impact on international trade Hard
A. Asymptomatic shipments are automatically considered pathogen-free
B. Quarantine decisions are based only on visible symptoms
C. The organism may threaten crops in the importing region
D. Trade restrictions apply only to nematodes that reduce grain weight

60 A country requires soil-free planting material because a nematode survives in root-associated soil. What risk is the measure primarily intended to reduce?

Impact on international trade Hard
A. Improvement of crop quality through soil removal
B. Mutation of nematodes during long-distance transport
C. Transmission through contaminated soil attached to commodities
D. Loss of nematode diversity in the exporting country