Lab 8

Question 1

-the “head” region of the tapeworm

Answer 1

SCOLEX

Question 2

scolex is equipped with some sort of holdfast organ – some variations include:

Answer 2

1) suckers 2) hooks 3) grooves

Question 3

-the types of sucker-like organs on scolices of cestodes that infect man:

Answer 3

1) Acetabula (sing. acetabulum)

2) Bothria

Question 4

Acetabula (sing. acetabulum)

• _____ or ______shaped with muscular wall
• usual pattern:

Answer 4

• circular or oval cup

- 4 equally spaced around scolex

Question 5

Bothria
Shape:
Usually __ in number
-________ location on scolex

Answer 5

• “Slit-like” shallow pits or long grooves
• 2
• Lateral or dorsoventral

Question 6

protruding dome-shaped area on anterior end of scolex

Answer 6

Rostellum

Question 7

• “armed” -

- “unarmed” -

Answer 7

• hooks are arranged on it This is the rule.

- no hooks

Question 8

(presence and absence of ______ and shape and arrangement of _____
are identification keys in cestodes)

Answer 8

• rostellum

- hooks

Question 9

region between scolex and strobila segments

Answer 9

neck

Question 10

contains stem cells that give rise to new proglottids

Answer 10

neck

Question 11

long chain of proglottids (segments)

depending upon species, from a few to thousands of proglottids

Answer 11

strobila

Question 12

Strobila

-each has sets of reproductive organs of ____ -“_____” in each set

Answer 12

• both sexes

- genitalium

Question 13

growth of strobila is called:

Answer 13

strobilization

Question 14

strobilization occurs from _____ end as new proglottids are added

Answer 14

anterior

Question 15

proglottids closest to scolex –

Answer 15

most immature

Question 16

“gravid” =

Answer 16

filled with eggs

Question 17

proglottids in strobila “_____fertilize” (rarely self-copulate within same proglottid)

Answer 17

-cross

Question 18

How proglottids are shed: depends upon:

Answer 18

species of cestode

Question 19

3 ways proglottids are shed:

Answer 19

1. intact gravid
2. proglottid disentigrates as shed and eggs go out with feces
3. eggs shed from attached proglottid through uterine pore

Question 20

-means an empty, formerly gravid proglottid

Answer 20

“Senile”

Question 21

Tegument is important in: (3)

Answer 21

1. absorption (cestodes dont have GI tract)
2. excretion of wastes
3. osmoregulation

Question 22

how does tegument effectively absorb nutrients?

Answer 22

-covered in microvilli called “microtriches” even on the suckers – increases
the absorptive area of tegument

Question 23

MUSCULAR SYSTEM:

• each proglottid has two layers of muscle:
• enables each segment to:

Answer 23

• longitudinal, transverse

- move independently

Question 24

NERVOUS SYSTEM:

• well developed in cestodes
• sensory: ____receptive, _____receptive

Answer 24

-tacto, chemo

Question 25

Which is rare in cestodes? monecious or dioecious?

Answer 25

dioecious

Question 26

dioecious cestodes do not infect:

Answer 26

man or his domestic animals

Question 27

______ reproduction is the Rule in cestodes

Answer 27

MONECIOUS

Question 28

-cestode fertilization occurs when repro systems ______

Answer 28

mature (as proglottids proceed toward posterior part of strobila)

Question 29

-self-mating within the same proglottid is the _____, not the ____.

Answer 29

-exception, rule

Question 30

sperm are transferred between:

Answer 30

mature proglottids that lie next to each other in intestine of definitive host

Question 31

-gravid proglottids – contain _____# of eggs

Answer 31

100’s to 1000’s

Question 32

2 different types of cestode egg shells?

Answer 32

Dipylidium type, taenia type

Question 33

Which type of egg shell is thin?

Answer 33

Dipylidium

Question 34

Which type of egg shell is thick?

Answer 34

Taenia

Question 35

Taenia type egg shell contain a _______ embryo within

Answer 35

hexacanth

Question 36

which species have a dipylidium type shell?

Answer 36

Diphyllobothrium latum Dipylidium caninum Hymenolepsis nana and H. diminuta

Question 37

which species have a taenia type shell?

Answer 37

Taenia sp., Echinococcus sp.

Question 38

-Most cestodes require minimum of two hosts for completion of cycle. There is always an exception: ________ can complete life cycle in same host. -- ________ host is optional for H. nana

Answer 38

- Hymenolepsis nana | - Invertebrate intermediate

Question 39

Cestode life span depends on species, but can last from _____ to _____

Answer 39

days, years

Question 40

_______ -the hexacanth larva in the egg

Answer 40

ONCOSPHERE

Question 41

________- juvenile (larval) form of tapeworm found in intermediate hosts

Answer 41

METACESTODE:

Question 42

general life cycle of cestodes

Answer 42

egg --�oncosphere (in egg) �-- metacestode (in intermediate host)� --adult worm (in definitive host)