Zoology Section 2
Needs of animals
Flatworms and round worms
Parasites
Activities for this section
• Read 647-653 flat worms and round
worms Nematoda
• Read Old Biology Book about
Platyhelminthes Chap 30
• Work on worksheets in binder (4 sides)
• Data Lab pg 652
• Parasite WEB QUEST
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PARASITE WEB QUEST
Log on to any computer in the school
click on My Computer
click on projects on 'tvhs-ad1.tvschools.net' (P:)
click on Taylor-Lehman
click on Zoology
click on webquest.html
follow the links
QUESTIONS
Answer the following questions for each of the five
cases presented in the Computer Lab activity. Write
complete answers.
• 1. What is the scientific name of the parasite? (Use
the proper format)
• 2. Hypothesize about the method of infection.
• 3. How will you treat each client’s disease.
GREATEST CONCERNS OF ANIMALS
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1.________________________
Solutions
– A. _______________________________
– B. be filled with water and limit evaporation (ex. Skin, shell,
cuticle)
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2. ____________________
Solutions
– A. ______________________________
– B. stay moist (oxygen in the air can be absorbed through the
skin)
– C. have a system to bring oxygen in and distribute it (ex. Gills,
lungs)
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3. _______________________
Solutions
– A. Bring food inside the body to the gut for digestion and …
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a. have all the cells close to the gut
B. have a system to distribute the digested food (ex. Blood stream)
GREATEST CONCERNS OF ANIMALS
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1.___WATER (remember the importance of water?) ___
Solutions
– A. ______________________
– B. be filled with water and limit evaporation (ex. Skin, shell,
cuticle)
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2. ____________________
Solutions
– A. _________
– B. stay moist (oxygen in the air can be absorbed through the
skin)
– C. have a system to bring oxygen in and distribute it (ex. Gills,
lungs)
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3. _______________________
Solutions
– A. Bring food inside the body to the gut for digestion and …
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a. have all the cells close to the gut
B. have a system to distribute the digested food (ex. Blood stream)
GREATEST CONCERNS OF ANIMALS
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1.___WATER (remember the importance of water?) ___
Solutions
– A. _____stay in the water_________________
– B. be filled with water and limit evaporation (ex. Skin, shell,
cuticle)
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2. ____________________
Solutions
– A. _________
– B. stay moist (oxygen in the air can be absorbed through the
skin)
– C. have a system to bring oxygen in and distribute it (ex. Gills,
lungs)
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3. _______________________
Solutions
– A. Bring food inside the body to the gut for digestion and …
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a. have all the cells close to the gut
B. have a system to distribute the digested food (ex. Blood stream)
GREATEST CONCERNS OF ANIMALS
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1.___WATER (remember the importance of water?) ___
Solutions
– A. _____stay in the water_________________
– B. be filled with water and limit evaporation (ex. Skin, shell,
cuticle)
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2. _____OXYGEN_______________
Solutions
– A. _________
– B. stay moist (oxygen in the air can be absorbed through the
skin)
– C. have a system to bring oxygen in and distribute it (ex. Gills,
lungs)
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3. _______________________
Solutions
– A. Bring food inside the body to the gut for digestion and …
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a. have all the cells close to the gut
B. have a system to distribute the digested food (ex. Blood stream)
GREATEST CONCERNS OF ANIMALS
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1.___WATER (remember the importance of water?) ___
Solutions
– A. _____stay in the water_________________
– B. be filled with water and limit evaporation (ex. Skin, shell,
cuticle)
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2. _____OXYGEN_______________
Solutions
– A. __stay in the water (oxygen dissolves in water) _______
– B. stay moist (oxygen in the air can be absorbed through the
skin)
– C. have a system to bring oxygen in and distribute it (ex. Gills,
lungs)
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3. _______________________
Solutions
– A. Bring food inside the body to the gut for digestion and …
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a. have all the cells close to the gut
B. have a system to distribute the digested food (ex. Blood stream)
GREATEST CONCERNS OF ANIMALS
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1.___WATER (remember the importance of water?) ___
Solutions
– A. _____stay in the water_________________
– B. be filled with water and limit evaporation (ex. Skin, shell,
cuticle)
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2. _____OXYGEN_______________
Solutions
– A. __stay in the water (oxygen dissolves in water) _______
– B. stay moist (oxygen in the air can be absorbed through the
skin)
– C. have a system to bring oxygen in and distribute it (ex. Gills,
lungs)
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3. ______FOOD_________________
Solutions
– A. Bring food inside the body to the gut for digestion and …
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a. have all the cells close to the gut
B. have a system to distribute the digested food (ex. Blood stream)
ANIMAL PHYLA
(INVERTEBRATES)
• I. PORIFERA –sponges
• II. CNIDARIA- jellyfish ,coral
III. phylum PLATYHELMINTHES –
“flat worms”
• examples fluke, planaria, tapeworm
• Examine specimens being passed around
the room
III. PLATYHELMINTHES –
characteristics
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Bilateral symmetry
Aquatic or semi aquatic
3 cell layers (see lab)
nervous tissue concentrated at anterior end
regeneration
hermaphrodites- contain both ovaries and
testies
• asexual reproduction by fragmentation
• every cell is near the surface of the body
(gas exchange)
Some cool marine flatworms
• Although very thin and delicate, flatworms
are active carnivores and scavengers,
using their proboscis to feed on dead or
injured animals and colonial animals such
as bryozoans and soft-corals. The worms
can quickly glide along the bottom by
using the fine hair like cilia which cover
their body. When disturbed they can swim
for a considerable period of time by
throwing the sides of their body into
undulating waves.
1. Class Turbellaria- planaria
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Free living in fresh water
See handout
Add to your notes
– DigestionNutrients absorbed
by intestinal wall
and waste goes out
through mouth
• Muscular pharynx
comes out of
central mouth to
feed
- Nervous system:
Brain, two nerve
cords, and lightsensitive eye spots
– Water balanceWater continually
enters by osmosis
NAME
HOSTS
INFECTION SITE
IN HUMANS
HOOKWORM
ASCARIS
TRICHINIA
ELEPHANTIASIS WORM
TAPEWORM
FLUKE
"SCHISTOSOMA"
SYMPTOMS
METHOD OF
PREVENTION
2. Class Trematoda- flukes,
“schistosomiasis”
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See handout about this
parasite on humans
and snails
3. Class Cestoda- tapeworms
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Not as much division of labor as in the
free living organism
No mouth nor digestive system
Absorbs nutrients directly from host’s
intestines
Highly specialized for reproduction
still the
phylum Platyhelminthes
• Class Cestoda- Parasitic
flatworms (tapeworms)
– Suckers and hooks attach
to walls of intestines
– Food absorbed from host’s
intestines directly through
the tapeworm’s skin
– Grow by producing a string
of rectangular body
sections (proglottids)
• Each proglottid is a
reproductive unit
• Added continually through
life
• May grow up to 12 m (40
ft.) long
• Most occur in vertebrates
• Dozen types in humans
• Taenia saginata- Beef
tapeworm
– Live in cow muscles in
cysts
– High temp. kills larvae
TAPEWORM LIFE CYCLE
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cow eats grass contaminated with eggs
embryo digs through intestines to blood stream
larva develop and burrow into muscle
cysts develop in muscle
human eats insufficiently cooked meat
cyst develops and attaches to intestine wall
robs nutrients
eggs released in feces
SCOLEX
SCOLEX
TAPEWORM ATTACHED TO
INTESTINAL WALL
Human consumes cysts
EGGS RELEASED FROM PROGLOTTIDS
Cow consumes eggs
CYSTS IN MUSCLE
OF COW
Brand new phylum
IV. Phylum NEMATODA“round worms”
• Examples Ascaris, Trichinella, hookworms
• Complete digestive system –mouth to
anus
• Free-living
• Parasites on plants, animals and man (50)
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1. HOOKWORM life cycle
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Hookworms are found in tropical and semitropical regions.
Their larva develop in the soil. Entrance of the larva to the
human body is through the skin, especially the skin of the feet.
Once through the skin the larva enters the person’s blood
vessels, traveling through the heart to the lungs.
Leaving the lungs, the larva migrates through the windpipe and
arrive in the person’s throat.
Being swallowed by their host, the larva enters the stomach and
continue on, using their jaws to attach themselves to the host’s
intestinal walls.
The larvae, sucking blood from their host’s intestinal walls, grow
into adult worms.
A victim usually develops anemia and lowered vitality as a result
of blood loss.
Adult worms mate and reproduce in the host’s intestines. A great
number of eggs are laid by the female and leave the body with
the feces.
Eggs that are deposited in warm soil develop into larvae and the
cycle is ready to be repeated.
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Blood
Heart
Lungs
Windpipe
Intestines
• 2. TRICHINA WORM
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The Trichina worm is a parasitic roundworm, which enters a
human’s body in the form of dormant larva cysts, imbedded in the
muscle of a pig.
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Trichina larva form dormant cysts in the muscles of pigs, also
in dogs, cats and rats.
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When a person eats a piece of insufficiently cooked pork
containing one or more of the live cysts, it is very possible that the
person’s digestive system enzymes will dissolve the cysts in the
intestines, freeing the larva.
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• The larva in the intestine then grow to mature trichinae worms and
produce a new generation of larvae.
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• The new larvae penetrate into the blood and lymph vessels and
travel to various body muscles where they form new cysts that
can become a very painful disease (TRICHINOSIS). They are
difficult to combat or remove because of their microscopic size.
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These cysts eventually die or in cases where an infected
animal is eaten by another anima, the cycle is renewed .
• VARIOUS RELIGIOUS GROUPS HAVE PROHIBITIONS ON
EATING PORK
• 3. ASCARIS WORM
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The Ascaris is a non-segmented parasitic round worm.
Eggs of the ascaris worms are found in contaminated
foods, such as pork, beef, fish, and vegetables. Untreated
water may also be contaminated.
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When contaminated food, improperly cooked, is eaten by
humans or other animals, the eggs, upon reaching the
intestines will hatch into larvae.
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The larva bore through the host’s intestinal walls, enter
the blood stream and travel to the lungs, through the windpipe
and down the host’s throat.
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Being swallowed by the host, the larvae again reach the
small intestines. This entire journey has taken about 10 days.
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Remaining in the host’s intestine (about 2 months) the
larvae grow to maturity. The female worms lay many fertilized
eggs (about 20,000 a day) The eggs pass out of the host’s
body along with the feces, which, when coming in contact with
food, eaten by another susceptible animal, starts the cycle
again.
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NAME
HOSTS
INFECTION
SITE
SYMPTOMS
IN HUMANS
HOOKWORM
ASCARIS
TRICHINIA
ELEPHANTIASIS
WORM
TAPEWORM
eggs in the soil
eggs in water
METHOD OF
PREVENTION
small intestines
enters
anemia,
vomiting
wear shoes
via the skin or
ingestion
constipation
diarrhea
defecate in
latrines
enter by mouth to
peritonitis,
enlarged liver
keep sewage water
away
small intestines and
lungsd
and spleen,
pneumonia
from drinking and
irrigation
fever and pain
cook meat
completely
thickening of
skin
kill mosquitos
malnutrition,
diarrhea
wash or cook food
rats, pigs and humans
hatch in stomach to
cysts in muscle
intestines and into
muscles
mosquitos transmits
obstruction of
lymphatic
filarial worm
system
food infected with eggs
digestive tract
abdominal
discomfort
FLUKE
"SCHISTOSOMA"
snail
penetrates skin and
fever, fatigue,
cough
kill snails
Migrates to lungs
and liver
abdominal pain,
diarrhea
avoid water with
snails
Practice problems
Practice problems
Practice problems
Practice problems
Topics
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Name phyla and classes
Provide examples of above
Contrast features of the 2 phyla
Lists sources of parasites
List methods of prevention
Describe life cycle of hookworm, fluke and
tapeworm
• List adaptations for parasitic life style
• Study worksheets
• Anatomy of a planaria and tapeworm