Fluke and Tapeworm Lab
Purpose
To observe and sketch the body and organ systems of flatworms in the Phylum Platyheminthes, as well as to investigate how endoparasites have been modified to better suit their way of life.
Materials
Live Planaria, if available
Mocroscope
Planaria, Chonorchis, and Taena scolex slides
Blank paper and pencil
Mocroscope
Planaria, Chonorchis, and Taena scolex slides
Blank paper and pencil
Method
Part 1: Planaria
1. Complete live planaria lab if specimens are present
2. If there are no live specimens, view and draw the planarian slide, labeling all its body parts and organs
Part 2: Taena
1. Examine the sole of the scolex of a tapeworm. Do a drawing and lable the hooks and suckers
Part 3: Clonorchis
1. Examin the Clonorchis slide. Do a drawing and lable the mouth, oral sucker, and gastrovascular cavity
Part 4: Fasciola Hepatica
1. Examine the Fasciola hepatica slide. Do a drawing and label the mouth, oral sucker, and gastrovascular cavity
1. Complete live planaria lab if specimens are present
2. If there are no live specimens, view and draw the planarian slide, labeling all its body parts and organs
Part 2: Taena
1. Examine the sole of the scolex of a tapeworm. Do a drawing and lable the hooks and suckers
Part 3: Clonorchis
1. Examin the Clonorchis slide. Do a drawing and lable the mouth, oral sucker, and gastrovascular cavity
Part 4: Fasciola Hepatica
1. Examine the Fasciola hepatica slide. Do a drawing and label the mouth, oral sucker, and gastrovascular cavity
Results
Analysis:
1. Q - A human tapeworm can be as long as 60 feet! How is this possible when the human intestine is only about 20 feet long?
A - Since the tapeworm is paper thin, it can fold itself over many times, allowing itself to only occupy a short section of intestine. By folding up, it also covers more of the intestinal tract, allowing it to absorb more nutrients.
2. Q - What is the function of the hooks and suckers on the scolex?
A - Once the tapeworm is in the small intestine, it needs to attatch to the intestinal wall. First, the suckers grab onto the wall, bringing the scolex close up against the side. The hooks on top then grap into the wall, firmly attatching the worm to the intestine. NOTE: the suckers on the scolex are not used to absorb nutrients; this is instead done all along the body of the worm.
3. Q - In what ways is Clonorchis similar to Planaria? In what ways are they different?
A - Both Clonorchis and Planaria have a visible mouth and gastrovascular cavity. However, the Planarias mouth is on its pharynx, while Chonorchis` is on the anterior of the worm`s body. Both worms have the flat, somewhat leaf shaped appearence, both in shape and the appearence of the gastrovascular cavity. Since the Planaria is a Free Living worm, it has sensory organs such as its eye spots and auricles (ears). Since the Clonorchis is a parasite, it has none of these, as it does not have to search its environment for nutrients.
4. Q - What do each of the germ layers develop into?
A - The ectoderm (outside) develops into skin and the nervous system of the worm. The mesoderm (middle) develops into all the muscles in the worm`s body, as well as its respective sexual organs. The endoderm (inside) develops into the digestive system, consisting of the mouth, intestine, and sometimes pharynx, of the worm.
5. Q - In what ways are flatworms more advanced than Cnidarians?
A - Flatworms are triploblastic, meaning they have a mesoderm along with the ectoderm and endoderm. They also have a completely different digestive system. Instead of food entering and exiting through the same hole, flatworms are able to excrete their waste through cells covering their body called flame cells. Their nervous system is arranged in a nerve ladder instead of a net, a more organized nervous system. Flatworms have bilateral symmetry, while Cnidarians have radial symmetry. Flatworms now have cephalization, beginning with a `brain` and sense organs that appear in the head of the worms, such as eye spots and auricles (ears).
6. Q - Name the characteristics of the phylum Platyhelminthes:
A) Type of symmetry - Bilateral, can be divided into two equal halves
B) Body plan - No real body cavity (acelomate), triploblastic (3 body wall layers), non-segmented body
C) Type of digestive system - Gastrovascular cavity with multiple openings (mouth (in) and flame cells (out))
D) Type of nervous system - Nerve ladder, with `brain` at end. First sensory organs
7. Q - Explain or define these terms:
A) Hemaphroditic - The animal has both female and male sex organs inside its body
B) Ladder type nervous system - The nervous system of the worm is arranged like a ladder, with two lateral nerve cords with many branches in between the two main nerves
C) Flame cells - Cells on the outside of the worms body that excrete the waste from the digestive system. This allows mouth to no longer be anus
D) Regeneration - In the worm`s body are stem cells. If the worm is cut in half, the worm continues to survive. It uses the stem cells to regrow any part of it that is missing from the other half. This eventually results in two fully grown worms
8.
A - Since the tapeworm is paper thin, it can fold itself over many times, allowing itself to only occupy a short section of intestine. By folding up, it also covers more of the intestinal tract, allowing it to absorb more nutrients.
2. Q - What is the function of the hooks and suckers on the scolex?
A - Once the tapeworm is in the small intestine, it needs to attatch to the intestinal wall. First, the suckers grab onto the wall, bringing the scolex close up against the side. The hooks on top then grap into the wall, firmly attatching the worm to the intestine. NOTE: the suckers on the scolex are not used to absorb nutrients; this is instead done all along the body of the worm.
3. Q - In what ways is Clonorchis similar to Planaria? In what ways are they different?
A - Both Clonorchis and Planaria have a visible mouth and gastrovascular cavity. However, the Planarias mouth is on its pharynx, while Chonorchis` is on the anterior of the worm`s body. Both worms have the flat, somewhat leaf shaped appearence, both in shape and the appearence of the gastrovascular cavity. Since the Planaria is a Free Living worm, it has sensory organs such as its eye spots and auricles (ears). Since the Clonorchis is a parasite, it has none of these, as it does not have to search its environment for nutrients.
4. Q - What do each of the germ layers develop into?
A - The ectoderm (outside) develops into skin and the nervous system of the worm. The mesoderm (middle) develops into all the muscles in the worm`s body, as well as its respective sexual organs. The endoderm (inside) develops into the digestive system, consisting of the mouth, intestine, and sometimes pharynx, of the worm.
5. Q - In what ways are flatworms more advanced than Cnidarians?
A - Flatworms are triploblastic, meaning they have a mesoderm along with the ectoderm and endoderm. They also have a completely different digestive system. Instead of food entering and exiting through the same hole, flatworms are able to excrete their waste through cells covering their body called flame cells. Their nervous system is arranged in a nerve ladder instead of a net, a more organized nervous system. Flatworms have bilateral symmetry, while Cnidarians have radial symmetry. Flatworms now have cephalization, beginning with a `brain` and sense organs that appear in the head of the worms, such as eye spots and auricles (ears).
6. Q - Name the characteristics of the phylum Platyhelminthes:
A) Type of symmetry - Bilateral, can be divided into two equal halves
B) Body plan - No real body cavity (acelomate), triploblastic (3 body wall layers), non-segmented body
C) Type of digestive system - Gastrovascular cavity with multiple openings (mouth (in) and flame cells (out))
D) Type of nervous system - Nerve ladder, with `brain` at end. First sensory organs
7. Q - Explain or define these terms:
A) Hemaphroditic - The animal has both female and male sex organs inside its body
B) Ladder type nervous system - The nervous system of the worm is arranged like a ladder, with two lateral nerve cords with many branches in between the two main nerves
C) Flame cells - Cells on the outside of the worms body that excrete the waste from the digestive system. This allows mouth to no longer be anus
D) Regeneration - In the worm`s body are stem cells. If the worm is cut in half, the worm continues to survive. It uses the stem cells to regrow any part of it that is missing from the other half. This eventually results in two fully grown worms
8.
Body structure
Eyes
Nervous system
Digestive system
Reproductive system
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Endoparasite - Taena
Extremely long worm with scolex (head) holding hooks and suckers
No eyes; parasitic
Nerve ladder leading up to sensory organs and ``brain`` in the head of the worm
Gastrointestinal cavity with multiple openings. Absorbs nutrients through skin all along body
Each section of body contains sex organs. These release eggs and sperm. They can also regrow into multiple worms if cut in two or more pieces
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Free living - Planaria
Shorter body, more leaf shapped. Have sensory organs on head, mouth on pharynx in body
Eye spots, as well as auricles (ears) situated in head in anterior of worm
Little to no nervous system, as it is parasitic
Gastrointestinal cavity with multiple openings. Consumes food with mouth on end of pharynx
Testes located at back of body, ovaries in middle. Releases sperm and eggs to reproduce
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Live Planarian Lab
Objectives
To observe the body structures and behaviors of a Planarian flatworm in various conditions, as well as to record regrowth time after cutting the worm into two sections.
Method
1. Take a small glass dish and fill it with clean water. Using a large water dropper, suck up a freshwater Planarian and put it into the dish.
A) Q: List 3 characteristics of flatworms.
A: - Have a gastrovascular cavity with multiple openings digestive system
- They rid themselves of wastes using pores along the side of their bodies called flame cells
- Free-living flatworms such as Planarians have some of the first basic sensory organs; Eye spots that detect shadows and auricles which act as ears and are located on the side of the Planarian's anterior region
B) Q: What type of symmetry does this worm have?
A: Bilateral symmetry
C) Q: Where do planarians live?
A: Planarians are free-living organisms that live outside of the human body. They rely on their sensory organs to locate food in their environment. Most Planarians live in or around water.
D) Observe the Planarian using a hand lense. Lable the eyespots and the anterior and posterior ends.
A) Q: List 3 characteristics of flatworms.
A: - Have a gastrovascular cavity with multiple openings digestive system
- They rid themselves of wastes using pores along the side of their bodies called flame cells
- Free-living flatworms such as Planarians have some of the first basic sensory organs; Eye spots that detect shadows and auricles which act as ears and are located on the side of the Planarian's anterior region
B) Q: What type of symmetry does this worm have?
A: Bilateral symmetry
C) Q: Where do planarians live?
A: Planarians are free-living organisms that live outside of the human body. They rely on their sensory organs to locate food in their environment. Most Planarians live in or around water.
D) Observe the Planarian using a hand lense. Lable the eyespots and the anterior and posterior ends.
2. Measure the planarian. Do this by removing a small amount of water from the dish and wait for the worm to stretch out. Remember to refill the dish after.
Length = 11mm
3. Observe the planarian for 5 minutes. Does it seem active or passive? How does it move? Does it swim or creep? Where in the dish does it spend most of its time? Make a current in the water with a pipette. How does the planarian react? Put this data in the table below:
Length = 11mm
3. Observe the planarian for 5 minutes. Does it seem active or passive? How does it move? Does it swim or creep? Where in the dish does it spend most of its time? Make a current in the water with a pipette. How does the planarian react? Put this data in the table below:
Movement
Worm Location
Reaction to Current
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Description
Slowly creeps around dish. Often stops and moves its anterior region as if it is looking around. Never stops moving, constantly exploring the dish.
Mostly does laps around the perimiter of the dish, occasionally turning towards the centre.
When the current hits the planarian, at first it curls up into a ball. However, instead of continuing to hide, it then begins to swim towards the source of the current until it is blown across the dish.
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4. Planarians are either left or right handed. This is discoverable by flipping the planarian over onto its dorsal side and seeing which way it turns to get back onto its front. If it rolls to the right, it is right handed, and if to the left, it is left handed. Do 5 trials to determine the handedness of the planarian and put the results into the table below:
Trial 1
Trial 2
Trial 3
Trial 4
Trial 5
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Which way does it turn (left or right)
Right Fakes to the left, but turns right
Right Right
Turns to the left, but then twists up and turns right all the way back over |
Based on the data, the planarian is right handed
5. Using the light from a microscope, design an experiment to test the planarians reaction to light. Describe the experiment:
We place the worm, on a lense dish, underneath the lens of a dissecting microscope. With the light off, we would first observe his activity with no light. Then, we would wait for it to swim overtop of the light, then turn it on right away.
Conduct the experiment to determine whether the planarian prefers dark or light. Record results in the table below:
We place the worm, on a lense dish, underneath the lens of a dissecting microscope. With the light off, we would first observe his activity with no light. Then, we would wait for it to swim overtop of the light, then turn it on right away.
Conduct the experiment to determine whether the planarian prefers dark or light. Record results in the table below:
Trial
1
2
3
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Initial activity
Did not explore the dish. Just stayed still, glancing around the dish
No movement once again
Began to circle the dish once again, making it very hard to locate. Eventually stayed still
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After five seconds of light
The moment the light turned on, the planarian darted out of the light much faster than previous movement
Did not move out of the light
Glanced around, as if trying to find the source or cause of the light, then slowly moved to the left of the dish
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In the first trial, the planarian appeared to favor darkness, and become very frightened once the light turned on. However, as the experiment went on, he seemed to recognize and get used to the appearence of the light and almost enjoy being in it by Trial 3.
6. Planarian Reproduction
Planarians are hemaphodites. Define this - A hemaphroditic organism posesses both male and female sex organs, and can reproduce without a partner
Planarians can also reproduce by regeneration. Define this - Regeneration is the ability to regrow lost body parts. Since planarians are made largely of stem cells, if cut in half, they can regrow any bodypart lost in the process. This method of reproduction is asexual.
Pour out some of the water so the planarian is mostly unsubmerged. When it stretches out, use a scalple to cut it cleanly in half. Replace the water and observe the two ends under a microscope. Fill in the table below:
Planarians can also reproduce by regeneration. Define this - Regeneration is the ability to regrow lost body parts. Since planarians are made largely of stem cells, if cut in half, they can regrow any bodypart lost in the process. This method of reproduction is asexual.
Pour out some of the water so the planarian is mostly unsubmerged. When it stretches out, use a scalple to cut it cleanly in half. Replace the water and observe the two ends under a microscope. Fill in the table below:
Posterior end
Anterior end
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Movement (Observations)
Slowly moving in circles along the bottom of the dish
No movement occuring at all |
I predict that, in five days, both halves of the planarian will have fully regenerated.