Trematodes Flashcards
Flatworms belong to what phylum?
Phylum Platyhelminthes
Flatworms are flattened in what manner?
A. Anteriorly
B. Dorsally
C. Dorsoventrally
D. Anteroposteriorly
C.
Parasites under Class Trematoda I
are called ________.
Flukes
Adult flukes will generally appear _______ in appearance.
Note: Schistosomes are an
exception as they are described to be elongated and cylindrical.
Leaf-like
Nonschistosomal flukes: ______
Schistosomes:_____
A. Monoecious; Diecious
B. Hermaphrodite; Monoecious
C. Diecious; Monoecious
D. Monoecious; Monoecious
A
Usual diagnostic stage of flukes
Egg
What is referred to as the “egg cap”?
Operculum
All of the eggs of flukes are operculated, except for what parasite species?
Schistosoma spp.
What is the function of the operculum?
A. Mechanical and Chemical
Protection
B. Aids the diffusion of nutrients
C. Escape passageway for the first larval stage
D. All of the above
C
Posterior region of fluke eggs where there is occasionally a presence of a thickening or a knob.
Note: This lies opposite to the operculum.
Abopercular end
A fluke egg is _______ if there is a presence of miracidia inside when it is laid. Otherwise, it is _______.
A. miracidiated; amiracidiated
B. mature; immature
C. unembryonated; embryonated
D. primary; secondary
B
Which of the following flukes lay ) & mature eggs?
I. Schistosoma spp.
II. Paragonimus westermani
IlI. Fasciola lanceolata
IV. Eurytrema pancreaticum
V. Fasciola hepatica
VI. Opisthorchis spp.
VII. Clonorchis spp.
VIII. Heterophyes heterophyes
A. All except I
B. All except VI and VIl
C. All except I|
D. All except Il and V
D
The following needs fish as their second intermediate host, except for:
A. Opisthorchis felineus
B. Clonorchis sinensis
C. Heterophyes heterophyes
D. Eurytrema pancreaticum
D
All of the following describes a miracidium, except for:
A. first larval stage
B. has a tail
C. motile
D. ciliated
E. free-swimming
B
What is always the first intermediate host of trematodes (flukes)?
Snail
The following are molluscan stages (happens inside a mollusk; snail), except for:
A. Redial stage
B. Miracidial stage
C. Cercarial stage
D. Sporocyst stage
B
What larval stage is terminated from the molluscan host?
Cercaria
All of the following describes a cercaria, except for:
A. last larval stage
B. has a tail
C. motile
D. ciliated
E. free-swimming
D
In what host are metacercariae expected to form?
Second Intermediate Host
Infective stage of non-schistosomal flukes to humans
Metacercaria
The following can be a second intermediate host of non-schistosomal flukes, except for:
A. Aquatic plant
B. Crab
C. Ants
D. Grasshopper
E. Fish
F. Snail
G. All of them can be second intermediate host
G
Arrange the following stages of non-schistosomal flukes in chronological order after escaping from the egg:
I. Miracidium
Il. Sporocyst
IlI. Redia
IV. Cercaria
V. Metacercaria
A. 1, 11, III, IV, V
B. 1, III, II, IV, V
C. V, IV, II, Il, |
D. 1, II, IV
A
Arrange the following stages of schistosomal flukes in chronological order after escaping from the egg:
I. Miracidium
II. Sporocyst
IlI. Redia
IV. Cercaria
V. Metacercaria
A. 1, 11, III, IV, V
B. I, III, 11, IV, V
C. V, IV, II, III, I
D. 1, 11, IV
D
In humans, where do metacercariae excyst after ingestion to become juvenile flukes?
Small Intestine
The following describes Schistosoma spp. eggs, except for:
A. Non-operculated
B. Mature when laid
C. Gives rise to miracidium
D. Dioecious
D.
Which of the following statements’ regarding Schistosoma spp. is false?
A. Schistosomes have multiple generations of sporocyst stages
B. Schistosomes typically do not have redial stages
C. Schistosomes do not have metacercarial stages
D. Schistosomes reinfect snails making them their second intermediate host
D
The cercaria of Schistosoma spp. is characterized by its _______ which lies posteriorly.
Forked tail
Mode of transmission of Schistosoma spp.
SKin penetration
What allows the cercaria of Schistosoma spp. to penetrate skin?
A. Forked tail
B. Histolytic enzyme
C. Miniscule size
D. All are correct
B
True or False?
The forked tail of Schistosoma spp. cercaria is left outside the skin once it penetrates the skin.
True
The stage after the cercaria has lost its tail during penetration of skin.
Schistosomule
Key Definitions
A group of parasites that in adult form are primarily non-segmented, flattened, and leaf shaped.
Trematodes
Key Definitions
Another name for the trematodes
Digenea