Phylum Nematoda
Characteristics:
-Roundworms
-Mostly free-living
-Triploblastic (Endo, Ecto, Meso)
-Pseudocoelomate (have a fake coelom between endoderm and mesoderm)
-Reproduce sexually
-Males have hooks at their posterior, females do not
-Very small
-Free-living nematodes are decomposers
-Mostly free-living
-Triploblastic (Endo, Ecto, Meso)
-Pseudocoelomate (have a fake coelom between endoderm and mesoderm)
-Reproduce sexually
-Males have hooks at their posterior, females do not
-Very small
-Free-living nematodes are decomposers
Lab:
Analysis:
1. In Ascaris in which direction do the muscles run? Vertically or Horizontally?
Vertically, so that the roundworm can 'inch' through its host by squishing up its circular muscle bands up, and retract them.
2. What forms the lateral line in Ascaris?
This line is made up of the Ascaris' mesoderm and it acts as an excretory system, releasing ammonia and other toxins.
3. Is there any evidence of sensory organs in the Ascaris worm?
No, there are no sensory organs found in the Ascaris simply because it has no use for them, living in its host's intestine it doesn't need eyespots or auricles, it has no conditions or predators to be concerned with.
4. In what ways is Ascaris adapted to a parasitic existence?
- Lack of sensory organs
- made up mostly of digestive and reproductive organs, so that it can reproduce as much as possible.
-Its size; being small, it can get to where it wants to be in its host as easy as possible.
5. Describe the lifecycle of Ascaris from egg to adult, and back to egg:
-After fertilization, an Ascaris egg will find its way into the host's digestive system through ingesting unwashed fruits and vegetables. After the eggs are swallowed, then will then hatch, and will be carried to the lungs through the circulatory system. The larvae will spend several weeks maturing within the lungs of the host, before making their way up the bronchial tree, to the throat. Once they are in the throat, they are then swallowed, ending up in the small intestine, where they will spend several months, feeding off of their host. They will then lay their eggs, which will following the digestive system out, and will end up in the host's feces, where the cycle will start again.
6. In what ways are the hookworms similar to Ascaris?
7. How does Necator enter the body? How does it enter the intestine?
8. for the Trichina worm, how does it compare to Necator and Ascaris?
9. How can Trichinosis be prevented?
10. What germ layer is the roundworm's pseudocoelom located between?
11. What organs and organ systems are located in the nematode's pseudocoelom?
12. In what ways are parasitic Nematoda different from their free-living relatives?
13. What are the advantages and disadvantages to being a parasite?
14. Make a table to compare the following worms for each of the following criteria:
Criteria: Enter, Live, Host, Effects, Prevention
Worms: Taena, Chlorchis, Ascaris, Necator, Trichina
Vertically, so that the roundworm can 'inch' through its host by squishing up its circular muscle bands up, and retract them.
2. What forms the lateral line in Ascaris?
This line is made up of the Ascaris' mesoderm and it acts as an excretory system, releasing ammonia and other toxins.
3. Is there any evidence of sensory organs in the Ascaris worm?
No, there are no sensory organs found in the Ascaris simply because it has no use for them, living in its host's intestine it doesn't need eyespots or auricles, it has no conditions or predators to be concerned with.
4. In what ways is Ascaris adapted to a parasitic existence?
- Lack of sensory organs
- made up mostly of digestive and reproductive organs, so that it can reproduce as much as possible.
-Its size; being small, it can get to where it wants to be in its host as easy as possible.
5. Describe the lifecycle of Ascaris from egg to adult, and back to egg:
-After fertilization, an Ascaris egg will find its way into the host's digestive system through ingesting unwashed fruits and vegetables. After the eggs are swallowed, then will then hatch, and will be carried to the lungs through the circulatory system. The larvae will spend several weeks maturing within the lungs of the host, before making their way up the bronchial tree, to the throat. Once they are in the throat, they are then swallowed, ending up in the small intestine, where they will spend several months, feeding off of their host. They will then lay their eggs, which will following the digestive system out, and will end up in the host's feces, where the cycle will start again.
6. In what ways are the hookworms similar to Ascaris?
7. How does Necator enter the body? How does it enter the intestine?
8. for the Trichina worm, how does it compare to Necator and Ascaris?
9. How can Trichinosis be prevented?
10. What germ layer is the roundworm's pseudocoelom located between?
11. What organs and organ systems are located in the nematode's pseudocoelom?
12. In what ways are parasitic Nematoda different from their free-living relatives?
13. What are the advantages and disadvantages to being a parasite?
14. Make a table to compare the following worms for each of the following criteria:
Criteria: Enter, Live, Host, Effects, Prevention
Worms: Taena, Chlorchis, Ascaris, Necator, Trichina