Worms, Worms, Worms! - Cambridge Isanti Schools
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Transcript Worms, Worms, Worms! - Cambridge Isanti Schools
The wiggly world of wild and
wonderful worms
Kingdom: Animalia
Phylum : Platyhelminthes (Flatworms)
Class: Turbellaria (Turbellarians)
Class: Cestoda (Tapeworms)
Class: Trematoda (Flukes)
Phylum: Nematoda (Roudworms)
Family: Oxyuridae (Pinworms)
Family: Ancylostomatidae (Hookworms)
Family: Filariidae (Filarial Worms)
Family: Ascaridae (Ascarids)
only a few cells thick
bilateral symmetry
muscles to move
no circulatory or
respiratory system
have 3 tissue layers
ectoderm
mesoderm
endoderm
free-living or parasitic
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cephalization – nerve
bundling at one end
acoelomate – lack of a
true body cavity
primitive “head”
two main nerves
one body opening
“head”
hermaphrodite – have
both male and female
reproductive cells
sexual reproduction
(don’t self-fertilize)
asexual reproduction (by
fragmentation)
Planarian (Turbellarian)
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marine
most are predators
some move with cilia
in addition to muscles
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endoparasites in
intestine of host
1mm – 10m long
hooks and suckers for
attachment to host
absorb nutrients
through their skin
proglottid – body
segment with
reproductive organs that
break off when mature
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endoparasites in
intestine or
ectoparasites on fishes
tegument – protective
outer layer
hooks and suckers for
attachment to host
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Schistosoma - blood fluke
4-stage life cycle
eggs are found in water
(Africa, Asia, S.America)
first larval stage enter
intermediate host (snails)
second larval stage can
reproduce asexually
larvae enter human host
through skin or ingestion
and cause damage to liver
and intestine
(schistosomiasis)
eggs are shed in urine and
feces
Kingdom: Animalia
Phylum : Platyhelminthes (Flatworms)
Class: Turbellaria (Turbellarians)
Class: Cestoda (Tapeworms)
Class: Trematoda (Flukes)
Phylum: Nematoda (Roudworms)
Family: Oxyuridae (Pinworms)
Family: Ancylostomatidae (Hookworms)
Family: Filariidae (Filarial Worms)
Family: Ascaridae (Ascarids)
round in cross-section
bilateral symmetry
better muscle
movement than
flatworms
has 3 tissue layers
ectoderm
mesoderm
endoderm
free-living or parasitic
cephelization – nerve
bundling at one end
pseudocoelom
primitive “head”
two main nerves
two body openings
acts as circulatory
system (nutrients and
oxygen)
separate sexes
sexual reproduction
1 cm long
50% of school age kids
have had it
itching around anus
fecal- oral
transmission (from
feces to mouth)
1/5 of world population
affected
can cause mild
diarrhea/ cramps/
anemia
larvae enter through
bare feet
move through
bloodstream, into lungs,
into intestine
attach and suck blood
live in blood or
lymphatic system
mosquito vector
some cause
elephantiasis
lymphatic fluid collects
in tissues
some cause
heartworm in dogs
weakness and fatigue,
can lead to death
most common human
worm infection
contracted through
contaminated food/water
lives in intestine of
pigs/horses/humans
can cause blockage
feed on host’s food
eggs shed through feces
and can live in soil for
many years