Module 4

Question 1

● Cylindrical in shape Has a complete alimentary canal

Answer 1

NEMATODA
Roundworms

Question 2

● sexes are separate Either free-living or parasitic

Answer 2

NEMATODA
Diecious

Question 3

● they possess a false coelom

Answer 3

NEMATODA
Pseudocoelomates

Question 4

● Flattened dorsoventrally in shape

Answer 4

PLATYHELMINTHES
Flatworms

Question 5

Absent digestive system

Answer 5

PLATYHELMINTHES

Question 6

Monoecious (Cestodes, Monoecious flukes)
Diecious (Blood flukes - [?] spp)

Answer 6

PLATYHELMINTHES
Schistosoma

Question 7

Strictly parasitic

Answer 7

PLATYHELMINTHES

Question 8

● Coelom (body cavity) is absent.

Answer 8

PLATYHELMINTHES
Acoelomates

Question 9

requiring more than 1 host in their life cycle, except Hymenolepis nana which may complete its lifecycle in 1 host.

Answer 9

heteroxeneous

Question 10

require 3 hosts (a definite host and 2 intermediate hosts — first intermediate host, and second intermediate host) to complete their lifecycle. And consist of 3 larval stages

Answer 10

pseudophyllids

Question 11

require 2 hosts (a definite host and an intermediate host), and consist of 2 larval stages

Answer 11

cyclophyllids

Question 12

The life cycle of cestodes consists of four developmental stages:

Answer 12

○Egg
○Oncosphere
○Metacestode

Question 13

●The ciliated oncosphore of pseudophyllids is termed

Answer 13

Coracidium

Question 14

do not possess cilia

Answer 14

oncosphere

Question 15

The hexacanth embryo develops into a [?] that becomes encysted in extra intestinal sites of the intermediate host.

Answer 15

metacestode larva

Question 16

It already contains scolex.

Answer 16

metacestode larva

Question 17

■Depending on the species, larval stages of cestodes may be described as either

Answer 17

solid or bladder-type

Question 18

1.Pseudophyllidean pattern

Answer 18

a.Solid larva
b.Procercoid
c.Plerocercoid or Sparganum

Question 19

2.Cyclophyllidean pattern

Answer 19

a.Cystic/Bladder larva/worm
b.Cysticercoid

Question 20

Metacestodes

Answer 20

1.Pseudophyllidean pattern
2.Cyclophyllidean pattern
3.Cysticercus
4.Coenurus
5.Yep

Question 21

has a fully developed cyst wall containinga single invaginated scolex. The hollow cavity is filled with f luid thus, it is called a true “bladder worm”; seen among Taenia species

Answer 21

3.Cysticercus

Question 22

multiple scolices developed from the innergerminal wall; seen in Multiceps multiceps.

Answer 22

4.Coenurus

Question 23

germinal layer may produce many scolices anddevelop many daughter bladders (or brood capsules), each of which, in turn, produces many protoscolices internally; seen in Echinococcus species.

Answer 23

5.Yep

Question 24

characterized by absence of body cavity

Answer 24

a.Solid larva

Question 25

solid, relatively globular, with the scolex invaginated into the body of the larva

Answer 25

b.Procercoid

Question 26

solid, elongated, with the head free or invaginated only into the neck

Answer 26

c.Plerocercoid or Sparganum

Question 27

- characterized by a body cavity that may or may not be well-developed and containing fluid

Answer 27

a.Cystic/Bladder larva/worm

Question 28

a.Cystic/Bladder larva/worm - characterized by a body cavity that may or may not be well-developed and containing fluid b.Cysticercoid- not well-developed, with a rather small body anteriorly, into which the scolex is invaginated, and frequently with solid, elongated caudal portion; seen among Hymenolepis species and Dypilidium caninum

Question 29

- not well-developed, with a rather small body anteriorly, into which the scolex is invaginated, and frequently with solid, elongated caudal portion; seen among Hymenolepis species and Dypilidium caninum

Answer 29

b.Cysticercoid

Question 30

○Among the pseudophyllids, the immature eggs embryonate and release the [?] in water which are ingested by its first intermediate host.

Answer 30

oncospheres (coracidia)

Question 31

○Within the first intermediate host the coracidium develops into a .

Answer 31

procercoid

Question 32

○The first intermediate host is ingested by the second intermediate host where the procercoid develops into a

Answer 32

plerocercoid larva

Question 33

■The definitive host becomes infected by ingestion of the intermediate host’s flesh containing the [?]. The [?] attaches into the intestinal mucosa, strobilates and develops into the adult worm. Eggs from the [?] are then passed in feces.

Answer 33

metacestode larva metacestode scolex gravid proglottids

Question 34

■The [?] are mature, thus are readily infective but hatch only after ingestion by intermediate host. Hatching of the eggs will release the [?] which migrate to extra intestinal sites and become a [?], which may be [?], depending on the species.

Answer 34

cyclophyllidean eggs oncospheres metacestode larva cysticercus, cysticercoid, coenurus, hydatid