Parasitology - Nematodes
Student Lab Study Questions
Matching:
1. For each of the nematodes listed, match up its infective form for humans. (Answers may be used
more than once or not at all.)
Parasite
Infective Form
_____ Ascaris lumbricoides
a. Ova
b. Rhabditiform larva
_____ Hookworm
c. Filariform larvae
d. Larvae in muscle tissue
_____ Enterobius vermicularis
_____ Trichuris trichiura
_____ Strongyloides stercoralis
2. For each of the nematodes listed, match its diagnostic form usually (most often) seen. (Answers
may be used more than once or not at all.)
Parasite
Infective Form
a. Ova
_____ Ascaris lumbricoides
b. Rhabditiform larva
c. Filariform larvae
_____ Hookworm
d. Larvae in muscle tissue
_____ Enterobius vermicularis
_____ Trichuris trichiura
_____ Strongyloides stercoralis
3. For each description listed, match the nematode it identifies. (Answers may be used more than once
or not at all.)
Parasite
Infective Form
a. Ascaris lumbricoides
_____ Asymmetrical ova, one side convex with the other side
b. Hookworm
flattened
c. Enterobius vermicularis
_____ Broadly oval ova with brown outer mammillate covering d. Trichuris trichiura
e. Strongyloides stercoralis
_____ Barrel-shaped ova with polar plugs
_____
Largest intestinal roundworm of man
_____
Larval form is seen in stool specimen of patients with
this infection
_____
Causes severe iron deficiency anemia
_____
Whipworm
_____
Female deposits ova in the perianal region, not in feces
Nematodes
CLS 419 Student Laboratory
Study Questions
Page 12
Multiple Choice:
4. What is the method of choice for demonstrating a pinworm infection?
a. Ova and parasite exam of stool
b. Ova and parasite exam of sputum
c. Scotch tape preparation from perianal area
d. Serological testing
5. What specimen(s) would be useful when suspecting an Ascaris infection?
a. Stool
b. Sputum
c. Urine
d. Both A and B
6. For filarial nematodes, what key characteristic(s) of the microfilarial form is/are used to identify them?
a. Sheathed or unsheathed
b. Distribution of nuclei within its tip
c. Length of buccal cavity
d. Both A and B
e. Both A and C
7. Match the images of various nematode forms with their identification.
_____ Ascaris ovum (unfertilized)
_____ Hookworm ovum
_____ Hookworm Rhabditiform larva
_____ Strongyloides Rhabditiform larva
_____ Trichuris ovum
_____ Enterobius ovum
Nematodes
CLS 419 Student Laboratory
Study Questions
Page 13
600µm X 5 µm
Short genital primordium
Long buccal cavity
220µm X 15 µm
Prominent genical primordium
Short buccal cavity
a.
b.
86µm X 40 µm
60µm X 35 µm
c.
d.
60µm X 25 µm
52µm X 25 µm
e.
Nematodes
CLS 419 Student Laboratory
f.
Study Questions
Page 14