PCA NEMATODES EXAM QUESTIONS AND
ANSWERS LATEST 2025-2026 UPDATE 100%
GUARANTEED SUCCESS | ALREADY RATED A+
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.
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
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)
M. chitwoodi (columbia)
M. naasi (barley)
Egg laying habits of ectoparasitic nematodes - Answer-Eggs are laid
singly in the soil around the roots, and females may lay up to 2,800 eggs
Egg laying habits of root-lesion nematodes. - Answer-Female lays one
to two eggs a day for many days
Egg laying habits of stem and bulb nematodes. - Answer-After
fertilization by a male, a female lays up to 10 eggs a day within host
tissue and up to 500 eggs in a lifetime.
Egg laying habits of foliar nematodes. - Answer-Relatively few eggs
laid. 20-30 total eggs has been observed in one species.
Egg laying habits of citrus nematodes - Answer-Egg masses of about
100 eggs are deposited into a gelatinous matrix.
Egg laying habits of root-knot nematodes. - Answer-Eggs are laid in a
gelatinous matrix at posterior end of the body, which may be within the
root partially or completely. Low survival.
Sedentary ectoparasite - Answer-Nematodes that feed on the outside of
the plant in one location for most of their life cycle.
, Ex: Ring Nematode (Criconemella, Macroposthhonia)
Migratory ectoparasite - Answer-Nematodes that feed on the outside of
the plant, but will move to different locations in their life cycle.
Ex: Dagger Nematode (Xiphinema spp.)
Migratory endoparasite - Answer-Nematodes that feed within the plant
and will move throughout the plant tissue in their life cycle.
Ex: Lesion nematodes (Pratylenchus spp.)
Sedentary endoparasites - Answer-Nematodes that feed within the plant
in one location for most of their life cycle.
Ex: Cyst nematodes (Heterodera spp.; Globodera spp.)
Survival stage of stem and bulb nematodes - Answer-Dried fourth
juvenile stage to survive drying. Facilitates survival and dispersal,
reactivated with moisture.
Survival stage of foliar nematodes - Answer-Some juveniles may adapt
to drying and be able to survive adverse conditions, reactivated with
moisture.
ANSWERS LATEST 2025-2026 UPDATE 100%
GUARANTEED SUCCESS | ALREADY RATED A+
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.
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
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)
M. chitwoodi (columbia)
M. naasi (barley)
Egg laying habits of ectoparasitic nematodes - Answer-Eggs are laid
singly in the soil around the roots, and females may lay up to 2,800 eggs
Egg laying habits of root-lesion nematodes. - Answer-Female lays one
to two eggs a day for many days
Egg laying habits of stem and bulb nematodes. - Answer-After
fertilization by a male, a female lays up to 10 eggs a day within host
tissue and up to 500 eggs in a lifetime.
Egg laying habits of foliar nematodes. - Answer-Relatively few eggs
laid. 20-30 total eggs has been observed in one species.
Egg laying habits of citrus nematodes - Answer-Egg masses of about
100 eggs are deposited into a gelatinous matrix.
Egg laying habits of root-knot nematodes. - Answer-Eggs are laid in a
gelatinous matrix at posterior end of the body, which may be within the
root partially or completely. Low survival.
Sedentary ectoparasite - Answer-Nematodes that feed on the outside of
the plant in one location for most of their life cycle.
, Ex: Ring Nematode (Criconemella, Macroposthhonia)
Migratory ectoparasite - Answer-Nematodes that feed on the outside of
the plant, but will move to different locations in their life cycle.
Ex: Dagger Nematode (Xiphinema spp.)
Migratory endoparasite - Answer-Nematodes that feed within the plant
and will move throughout the plant tissue in their life cycle.
Ex: Lesion nematodes (Pratylenchus spp.)
Sedentary endoparasites - Answer-Nematodes that feed within the plant
in one location for most of their life cycle.
Ex: Cyst nematodes (Heterodera spp.; Globodera spp.)
Survival stage of stem and bulb nematodes - Answer-Dried fourth
juvenile stage to survive drying. Facilitates survival and dispersal,
reactivated with moisture.
Survival stage of foliar nematodes - Answer-Some juveniles may adapt
to drying and be able to survive adverse conditions, reactivated with
moisture.
