PCA Nematodes Exam Newest 2026-2027 With
Complete 200 Questions And Correct Detailed
Answers| Brand New Version!
Describe the relative size of plant feeding nematodes. - ANSWER-Great
variability. Range from 0.25 um to 12 mm in length.
Name five to six life stages of plant-parasitic nematodes. - ANSWER-Egg,
juvenile 1, J2, J3, J4, adult
Shape and size of root-knot nematode - ANSWER-Females are round
and lose their veriform shape as adults, males retain veriform shape
Shape and size of cyst nematode - ANSWER-Adult female is swollen,
eggs retained inside of cyst and cyst is left behind after female dies
Shape and size of lesion nematode - ANSWER-Small, needle-like
Describe how nematode shape affects the choice of extraction method.
- ANSWER-Larger nematodes that are swollen may be observed on the
root system, but smaller nematodes require actual extraction.
1|Page
,Define veriform. - ANSWER-Worm-shaped
Describe the major difference between the veriform stage and other
nematode life stages. - ANSWER-Veriform stages are mobile, swollen
stages are not.
Describe the feeding apparatus of plant-parasitic nematodes and how it
is used to feed on plants. - ANSWER-Stylet is used to feed. It pierces the
plant, and draws nutrients from the plant.
List two groups of nematodes by common name that exhibit sexual
dimorphism. - ANSWER-Cyst and root-knot nematodes
Describe the differences in shape between males and females in
nematodes that exhibit sexual dimorphism. - ANSWER-Males are
veriform, whereas females are swollen.
Describe how nematodes move. - ANSWER-Nematodes move with
snake-like movements in short distances. For long distances, they move
with infected material, water, and equipment.
List the major environmental/ecological factors that influence the time
it takes a nematode to complete its life cycle. - ANSWER-Temperature,
moisture, availability of food from the host.
2|Page
,Identify the host(s) of some non-plant parasitic nematodes. - ANSWER-
Animals, humans, insects
Ectoparasite - ANSWER-Nematode that feeds on the outside of the
plant.
Endoparasite - ANSWER-Nematode that feeds on the inside of the
plant.
List three ways ectoparasitic and endoparasitic species differ. -
ANSWER-Ectoparasites move to different plants.
Endoparasites move inside the plant tissue.
Ectoparastites are sampled from the soil, endoparasites are sampled
from the plant.
Identify by genus and common name the major ectoparasitic nematode
groups. - ANSWER-Xiphinema spp. - Dagger
Belonolaimus spp. - Sting
Trichodorus spp. - Stubby-root
Longidorus spp. - Needle
Paratylenchus spp. - Pin
Criconemoides & Mesocriconema spp. - Ring
3|Page
, Helicotylenchus & Rotylenchus spp. - Spiral
Tylenchorhynchus spp. - Stunt
Identify by genus and common name the major endoparasitic
nematode groups. - ANSWER-Meloidogyne spp. - Root-knot
Heterodera & Globodera spp. - Cyst
Pratylenchus spp. - Lesion
Radopholus spp. - Burrowing
Rotylenchulus reniformis - reniform
List the two most economically important species of root-lesion
nematodes on perennial crops in California by genus and species. -
ANSWER-Pratylenchus vulnus & Pratylenchus penetrans
List the two economically important cyst nematodes in California by
genus and species. - ANSWER-Heterodera schachtii & Heterodera
cruciferae
List five major root-knot nematodes in California by genus and species. -
ANSWER-Meloidogyne Incognita (southern)
M. hapla (northern)
M. javanica (Javanese)
M. arenaria (peanut)
4|Page
Complete 200 Questions And Correct Detailed
Answers| Brand New Version!
Describe the relative size of plant feeding nematodes. - ANSWER-Great
variability. Range from 0.25 um to 12 mm in length.
Name five to six life stages of plant-parasitic nematodes. - ANSWER-Egg,
juvenile 1, J2, J3, J4, adult
Shape and size of root-knot nematode - ANSWER-Females are round
and lose their veriform shape as adults, males retain veriform shape
Shape and size of cyst nematode - ANSWER-Adult female is swollen,
eggs retained inside of cyst and cyst is left behind after female dies
Shape and size of lesion nematode - ANSWER-Small, needle-like
Describe how nematode shape affects the choice of extraction method.
- ANSWER-Larger nematodes that are swollen may be observed on the
root system, but smaller nematodes require actual extraction.
1|Page
,Define veriform. - ANSWER-Worm-shaped
Describe the major difference between the veriform stage and other
nematode life stages. - ANSWER-Veriform stages are mobile, swollen
stages are not.
Describe the feeding apparatus of plant-parasitic nematodes and how it
is used to feed on plants. - ANSWER-Stylet is used to feed. It pierces the
plant, and draws nutrients from the plant.
List two groups of nematodes by common name that exhibit sexual
dimorphism. - ANSWER-Cyst and root-knot nematodes
Describe the differences in shape between males and females in
nematodes that exhibit sexual dimorphism. - ANSWER-Males are
veriform, whereas females are swollen.
Describe how nematodes move. - ANSWER-Nematodes move with
snake-like movements in short distances. For long distances, they move
with infected material, water, and equipment.
List the major environmental/ecological factors that influence the time
it takes a nematode to complete its life cycle. - ANSWER-Temperature,
moisture, availability of food from the host.
2|Page
,Identify the host(s) of some non-plant parasitic nematodes. - ANSWER-
Animals, humans, insects
Ectoparasite - ANSWER-Nematode that feeds on the outside of the
plant.
Endoparasite - ANSWER-Nematode that feeds on the inside of the
plant.
List three ways ectoparasitic and endoparasitic species differ. -
ANSWER-Ectoparasites move to different plants.
Endoparasites move inside the plant tissue.
Ectoparastites are sampled from the soil, endoparasites are sampled
from the plant.
Identify by genus and common name the major ectoparasitic nematode
groups. - ANSWER-Xiphinema spp. - Dagger
Belonolaimus spp. - Sting
Trichodorus spp. - Stubby-root
Longidorus spp. - Needle
Paratylenchus spp. - Pin
Criconemoides & Mesocriconema spp. - Ring
3|Page
, Helicotylenchus & Rotylenchus spp. - Spiral
Tylenchorhynchus spp. - Stunt
Identify by genus and common name the major endoparasitic
nematode groups. - ANSWER-Meloidogyne spp. - Root-knot
Heterodera & Globodera spp. - Cyst
Pratylenchus spp. - Lesion
Radopholus spp. - Burrowing
Rotylenchulus reniformis - reniform
List the two most economically important species of root-lesion
nematodes on perennial crops in California by genus and species. -
ANSWER-Pratylenchus vulnus & Pratylenchus penetrans
List the two economically important cyst nematodes in California by
genus and species. - ANSWER-Heterodera schachtii & Heterodera
cruciferae
List five major root-knot nematodes in California by genus and species. -
ANSWER-Meloidogyne Incognita (southern)
M. hapla (northern)
M. javanica (Javanese)
M. arenaria (peanut)
4|Page
