lec 11

Question 1

turbellarians
Nervous system?
Tissues?
Epidermis?

Answer 1

flatworms
-have extensively cilliated, glandular epidermis
-multiciliated epithelial cells produces mucus
-acoelomate
-solidly packed w tissues
-ladder-like nervous
systems w anterior ganglion(brain)
-eyes at anterior end
-clusters of
chemoreceptors in extensions of head

Question 2

how do the epithelial cells produce mucus in turbs?

Answer 2

via rod-shaped crystalline rhabdites

Question 3

Turbellaria gut

Answer 3

gut may be simple and sac-like
or three-branched
or multibranched

Question 4

excretion of metabolic wastes is via
turbs

Answer 4

protonephridia

Question 5

how do turbellia digest

Answer 5

start digestion externally by secreting enzymes
on the food

Question 6

how do turbellia egest

Answer 6

through the mouth

Question 7

Turbellaria fertilizatoin
Sexes?

Answer 7

-typically hermaphroditic
- transfer is via copulation
-intromittent organ penis to vagina
- or traumatic insemination in
which sperm is introduced through the
epiderms
- penis-
fencing

Question 8

Turbellaria reproduction

Question 9

Turbellaria cleavage

Answer 9

only some turbellarians show classic spiral cleavage

Question 10

Parasitic platyhelminths groups

Answer 10

Monogenea Trematoda (flukes) and Cestoda
(tapeworms

Question 11

Parasitic platyhelminths differences from turbellarians

Answer 11

lack eyes, epidermis lacks cilia in adults, syncytial epithelium

Question 12

syncytial epithelium

Answer 12

protect them from the host’s
digestive system
is a synapomorphy of the neodermata

Question 13

Parasitic platyhelminths life cycle

Answer 13

produce lots of eggs
-final (= definitive) host is the site of sexual
reproduction
-one or more intermediate hosts

Question 14

intermediate host in neodermata

Answer 14

-main function is
to enhance transmission to definitive host
-amplification of infective stages via asexual
reproduction
-altering behaviour of
intermediate hosts

Question 15

Cohort Trematoda
Definitive features?
What gut?
Common name?

Answer 15

flukes
-oral sucker
-2-branched gut

Question 16

trematoda nervous system

Answer 16

simplified
ladder-like nervous system

Question 17

nervous system common
in parasites

Answer 17

reduced

Question 18

Class/Cohort Cestoda
Hosts?
Gut?
Definitive features??

Answer 18

-tapeworms
-typically >2 hosts with final host being a vertebrate
-no mouth or gut
-adult has scolex

Question 18

Trematoda definitive host and intermediate hosts

Answer 18

-definitive host typically a vertebrate
-intermediate hosts usually include a mollusc

Question 19

how do trematoda feed

Answer 19

-taking it into the mouth
with the help of the pumping
pharynx

Question 20

nutrients are taken
in by
Cestoda

Answer 20

pinocytosis
Cell drinking

Question 21

Cestoda
segments
what do they contain

Answer 21

proglottids
-packed with
fertilized eggs
-eggs and sometimes proglottids leave host with feces

Question 22

Nemertea
Circ system?
Common name?
Gut?

Answer 22

-ribbon worms
-share many traits with turbellarian flatworms
-complete gut with anus
-closed circulatory system that is eucoelomic

Question 23

what is that wack ass tongue thing in nemertea

Answer 23

eversible
proboscis that is kept in a
rhynchocoel

Question 24

rhynchocoel

Answer 24

is a eucoelomic
cavity

Question 25

nemerteans method of catching prey

Answer 25

predatory and capture prey by
shooting out their proboscis via hydrostatic pressure

Question 26

special proboscis

Answer 26

proboscis is tipped with one or more stylets that puncture the prey like a harpoon and may inject toxin

Question 27

nemertea reproduction

Answer 27

external fertilizatoin
in some cases, sperm released outside female body in gelatinous mucus, then taken in by female and boom internal fertilization

Question 28

nemertea development
Weirdness?

Answer 28

direct or indirect also pilidium larva

Question 29

pilidium larva

Answer 29

in some taxa part of the larva pinches off internally and grows into the juvenile. juvenile then breaks out of larva and eats it, and takes up a benthic life

Question 30

importance of parasitic platyhelminths

Answer 30

affect human and livestock health

Question 31

Echinococcus canadensis(tapeworm)

Answer 31

cause hydatid cysts in many
organs in humans

Question 32

invasive terrestrial flatworm

Answer 32

caused the decline and extinction of land snails

Question 33

nemertean genus Carcinonemertes

Answer 33

live on the undersides of female crabs and prey on their eggs
-implicated in collapse of crab fisheries

Question 34

Medical nemerteans

Answer 34

-produce defensive chemicals,
including a tetrodotoxin
-can be lethal if eaten