Download Worm Essential Questions

1.
Worm Essential
Questions
Marine Biology
2.
–
Platyhelminthes - flatworms
Nemertea – ribbon worms
or proboscis worms
Nematoda - roundworms
Annelida – segmented
worms
3. Flatworms make up what
marine worm phylum?
What is a coelom? What is the difference between a
coelomate, pseudocoelomate and an acoelomate?
A coelom is a fluid filled
cavity surrounded by cells
(mesoderm) that forms in
development
What are the four major phyla of
marine worms? (in order from least
to most complex)
The coelom cavity gives room
for organs to develop
Platyhelminthes
Coelomate is an organism
that has a coelom;
segmented worms (all
vertebrates)
Pseudocoelomate is an
organism that has a fluid
filled cavity partially
surrounded by cells
(mesoderm); roundworms
Acoelomates are organisms
without a coelom; no body
cavity for internal organs;
flatworms
4. What kind of digestive system
do worms in phylum
Platyhelminthes have?
Simple digestive system with one opening
that is both a mouth and an anus
5. How do most Platyhelminthes
get their food? What is one
exception?
Most are parasites.
(tapeworms and
flukes)
One exception is
Tubellaria
(planarians = freefreeliving flatworms)
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6. How do parasitic
tapeworms live in a host?
Tapeworms have a head
(called a scolex)
scolex) that has
hooks and suckers that
latch on to a host
and repeating units called
proglottids
–
7.
Tapeworms
each proglottid is
detachable and has
muscles, nerves, and
reproductive organs
each proglottid can
have 100,000 eggs
(some worms have
2,000 proglotids)
proglotids)
What is the lifecycle of parasitic flatworms
called flukes? What disease is commonly
caused by blood flukes?
Fluke enters organs of
vertebrate (ex.
Human) feeds on cells, blood,
or nutrients lays eggs that pass out
in waste larvae infect
intermediate host
(snail) new larvae leave
intermediate host and
infect final host (ex.
human)
Schistosomiasis
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8. How do Platyhelminthes
reproduce?
Sexually – most are
hermaphrodites that
send sperm down
tubes to reach eggs
Asexually – by
regeneration
–
OneOne-way digestive system with one mouth
and one anus
11.How
11.How do most
Nemerteans get their
food?
12.What
12.What is the longest
animal in the world?
Nemertea
Ex. If one is cut in
half, the head grows a
new tail and the tail
grows a new head
10. What kind of digestive system
do Nemerteans and Nematodes
have?
9. Which marine worm
phylum consists of
“ribbon worms”?
Lineus longissimus (a
type of ribbon worm)
60 meters long
longer than
Siphonophores and Blue
Whales
Carniverous hunters that search in the
sand for prey
Also called proboscis worms
13.Which
13.Which marine worm
phylum consists of
roundworms?
Nematoda
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14.How
14.How do most Nematodes
get their food?
INFESTED CATERPILLAR
Most are freefreeliving and are
carnivores or
herbivores
Many are parasitic
worms that live in
the digestive
system of a host
15. How many species of
roundworms infect human
beings?
RELEASE OF NEMATODES FROM
About 50
16. What are some of the methods
roundworms use to invade and
infect humans?
Ascaris – swallow eggs from dirty hands; eggs
hatch in intestine, move to lungs through the
bloodstream and are coughed up and swallowed
causing reinfection
Hookworms – people walk on contaminated soil
with bare feet; worm crawls in and infects
Pinworms – most common in children; kids eat
something that is contaminated with eggs;
females lay eggs near anus; kids scratch, eat and
reinfect themselves
Trichinella – undercooked pork; causes
Trichinellosis
Hookworm lifecycle
Ascaris
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Hookworms
Pinworms
A nine year-old Brazilian boy, displaying the hookworms and tapeworms he
expelled when treated by the Rockefeller Foundation staff
Trichinella lifecycle
17. How are segmented worms
different from other marine
worms?
They are more
anatomically complex
They have nephridia,
nephridia,
a heart/circulatory
system, and
sometimes even
jaws, complete
digestive tract,
They have
metamerism = body
segments
Trichinella
18. Which marine worm phylum consists of
segmented worms? Which class has the
most marine worm species?
Annelida
Class Polychaeta has the most marine
species
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19.What
19.What are some specific
types of Polychaete
worms?
Tubeworms – live
on coral reefs
Bristleworms –
live on coral reefs
and sting and
burn when
touched
Spongeworms –
live on sponges
Fireworms – live
on the top of fire
coral
20. What are some of the
characteristics of annelids
called leeches?
Most live in
freshwater streams or
rivers
Parasites that suck
blood from hosts
(ducks, turtles, fishes,
people)
Bite doesn’t hurt
because they release
an anesthetic
Also release a
chemical the prevents
blood from clotting can be used in
medicine
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