Phylum Annelida
Characteristics
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✏ Triploblastic -> True coelom: coordinated digestion
✏ Bilateral Symmetry ✏ Protostome ✏ Respiration through skin ✏ Closed Circulatory System ✏ Hermaphroditic, limited regeneration ✏ Anterior Brain :connected to ventral nerve cord |
The Annelids
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Annelid Lab
Lab Analysis:
1. What is the name of the pumping organs of an earthworm?
The aortic arches also known as hearts. The earthworm has five of them that pump blood through its circulatory system
2. In the earthworm, trace the parts of the digestive tract through which food passes.
Prostomium -> Mouth -> Pharynx -> Esophagus -> Crop -> Gizzard -> Intestine -> Nephridia -> Anus.
3. Which parts of the earthworm serve as its brain? How are these parts connected to the rest of the body?
The earthworm has a ganglion in the anterior region of the worm. A ventral nerve cord is connected to the ganglion and runs the length of the worm.
4. Which of the parts of the earthworm’s body that you saw are included in the excretory system?
We saw the nephridia ( a squiggle like structure) and the anus.
5. How can you find out whether an earthworm eats soil?
By cutting open its digestive system (most likely the intestine) and examining the contents.
6. Among the earthworm’s structural adaptations are its setae. How do you think the earthworm’s setae make it well adapted to its habitat?
The seatae make the earthworm especially adapted to its environment because they allow the worm to move more easily in the soil.
7. How is the earthworm’s digestive system adapted for extracting relatively small amounts of food from large amounts of ingested soil?
It has special organs (crop and gizzard) that separates the dirt from its food. Which then travels to the intestine is very large and adapted to maximize nutrient absorption. The remaining waste is excreted through the anus.
8. Your dissection of the earthworm did not go beyond segment 32. What will you observe if you dissect the remainder of the worm to its posterior end?
We would have observed identical segments run to the end of the worm. We would have also seen the nephridia and intestines.
9. What did each germ layer develop into in the earthworm?
The ectoderm develops into the skin and nervous system. The mesoderm develops into the muscle (attached to the ectoderm) and the excretory, reproductive and circulatory systems. Finally, the endoderm develops into the digestive system and other remaining systems.
10. What is the function of the nephridium? How does it complete its function?
Its function is to filter coelomic fluid by taking the coelomic fluid from the previous segment. Wastes are excreted out through tubes in the skin and other fluids are sent back into the body.
11. How is the sandworm similar and different to the earthworm?
12. How is the leech designed to live as an ectoparasite? What are the similarities and differences between the leech and the earthworm?
1. What is the name of the pumping organs of an earthworm?
The aortic arches also known as hearts. The earthworm has five of them that pump blood through its circulatory system
2. In the earthworm, trace the parts of the digestive tract through which food passes.
Prostomium -> Mouth -> Pharynx -> Esophagus -> Crop -> Gizzard -> Intestine -> Nephridia -> Anus.
3. Which parts of the earthworm serve as its brain? How are these parts connected to the rest of the body?
The earthworm has a ganglion in the anterior region of the worm. A ventral nerve cord is connected to the ganglion and runs the length of the worm.
4. Which of the parts of the earthworm’s body that you saw are included in the excretory system?
We saw the nephridia ( a squiggle like structure) and the anus.
5. How can you find out whether an earthworm eats soil?
By cutting open its digestive system (most likely the intestine) and examining the contents.
6. Among the earthworm’s structural adaptations are its setae. How do you think the earthworm’s setae make it well adapted to its habitat?
The seatae make the earthworm especially adapted to its environment because they allow the worm to move more easily in the soil.
7. How is the earthworm’s digestive system adapted for extracting relatively small amounts of food from large amounts of ingested soil?
It has special organs (crop and gizzard) that separates the dirt from its food. Which then travels to the intestine is very large and adapted to maximize nutrient absorption. The remaining waste is excreted through the anus.
8. Your dissection of the earthworm did not go beyond segment 32. What will you observe if you dissect the remainder of the worm to its posterior end?
We would have observed identical segments run to the end of the worm. We would have also seen the nephridia and intestines.
9. What did each germ layer develop into in the earthworm?
The ectoderm develops into the skin and nervous system. The mesoderm develops into the muscle (attached to the ectoderm) and the excretory, reproductive and circulatory systems. Finally, the endoderm develops into the digestive system and other remaining systems.
10. What is the function of the nephridium? How does it complete its function?
Its function is to filter coelomic fluid by taking the coelomic fluid from the previous segment. Wastes are excreted out through tubes in the skin and other fluids are sent back into the body.
11. How is the sandworm similar and different to the earthworm?
12. How is the leech designed to live as an ectoparasite? What are the similarities and differences between the leech and the earthworm?
Phylum Mollusca
Characteristics
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✏ True coelom: coordinated digestion
✏ Protostome ✏ Bilateral Symmetry ✏ Ventral muscular foot, visceral mass, mantle ✏ Sexual Reproduction |
The Molluscs
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Squid Dissection
*Note: I was away on the day of this lab so therefore most of my notes are based on other people's' notes and lab results.*
This is not my picture: To see original picture click on the picture and it will take you to the website of the owner of the picture
Lab Analysis:
1. How are arms and tentacles similar and different?
They both have suckers but arms have them have them all along their surface while tentacles only have them at the end. Arms are shorter than tentacles but there are more arms than tentacles.
2. How are cephalopods similar and different to bivalves?
Cephalopods and Bivalves both have gills and are molluscs. However cephalopods are predators, motile and have advanced eyes whereas bivalves filter feed, are sessile, and have no sensory organs.
3. Was your squid a boy or a girl? How did you determine this?
I was not present during the dissection but I would have determined the sex of the squid by looking at the colour of its r reproductive organs. If they are milky colour (sperm) then they are male, whereas if they are a translucent yellow (eggs) then they are female.
4. Trace the path of food through your squid.
Beak -> Intestines -> Crop -> Stomach -> Anus.
5. Why are the brachial hearts so close to the gills?
So oxygen has a faster and shorter distance to cover to get to the circulatory system which allows for a quick gas exchange process.
1. How are arms and tentacles similar and different?
They both have suckers but arms have them have them all along their surface while tentacles only have them at the end. Arms are shorter than tentacles but there are more arms than tentacles.
2. How are cephalopods similar and different to bivalves?
Cephalopods and Bivalves both have gills and are molluscs. However cephalopods are predators, motile and have advanced eyes whereas bivalves filter feed, are sessile, and have no sensory organs.
3. Was your squid a boy or a girl? How did you determine this?
I was not present during the dissection but I would have determined the sex of the squid by looking at the colour of its r reproductive organs. If they are milky colour (sperm) then they are male, whereas if they are a translucent yellow (eggs) then they are female.
4. Trace the path of food through your squid.
Beak -> Intestines -> Crop -> Stomach -> Anus.
5. Why are the brachial hearts so close to the gills?
So oxygen has a faster and shorter distance to cover to get to the circulatory system which allows for a quick gas exchange process.
Phylum Arthropoda
Characteristics
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✏ Triploblastic -> True coelom: coordinated digestion
✏ Protostome ✏ Exoskeleton ✏ Sexual Reproduction ✏ Bilateral Symmetry ✏ Open Circulatory System ✏ Respiration through gills/ book lungs/ tracheids ✏ Most have 3 Body Regions ( Arachnids have 4): Head, Thorax and Abdomen ✏ Short lifespan ✏ Some have the ability to fly ✏ Five Classes: 1. Diplopoda -> Ex; Millipedes 2. Chilopoda -> Ex; Centipedes 3. Crustacea -> Ex; Crayfish 4. Arachnida -> Ex; Spiders 5. Insecta -> Ex; All other insects |
The Arthropods
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Grasshoper Lab
2. The sex of my grasshopper is male. I know this because there is no ovipositor and because it has claspers.
3. What is the function (not structure!!) of the following mouthparts:
Labrum: Protects the rest of the mouthparts
Labium: Holds Food
Maxilla: Chew
Mandible: Help pierce and chew food
Hypopharynx: "Tongue" -> Produces saliva and aids with the eating process
3. What is the function (not structure!!) of the following mouthparts:
Labrum: Protects the rest of the mouthparts
Labium: Holds Food
Maxilla: Chew
Mandible: Help pierce and chew food
Hypopharynx: "Tongue" -> Produces saliva and aids with the eating process
6. What have you learned from this lab about grasshoppers? About arthropods?
There are a lot of mouthparts and some were really hard to identify. Overall it was a neat dissection and makes you see things in a broader spectrum; how things so small can be so complex.
There are a lot of mouthparts and some were really hard to identify. Overall it was a neat dissection and makes you see things in a broader spectrum; how things so small can be so complex.
Crayfish Lab
1. How many appendages did the crayfish have?
It had 18 appendages.
It had 18 appendages.
3. How do the mouthparts of a crayfish compare to the mouthparts of a grasshopper?
There's many more mouthparts on the crayfish than the grasshopper, this makes them harder to identify and isolate since they are all small and clustered in the same area.
4. How does the thickness of the exoskeleton around the joints compare with the thickness around the rest of the leg?
The exoskeleton is much thinner around the joints.
5.What sex is the crayfish? How do you know?
My crayfish is male because it has a pseudopenis.
6. Why is there so much surface area on the gills of a crayfish?
So that there is a larger surface filtering water and making gas exchange, this makes it a much faster and efficient process
There's many more mouthparts on the crayfish than the grasshopper, this makes them harder to identify and isolate since they are all small and clustered in the same area.
4. How does the thickness of the exoskeleton around the joints compare with the thickness around the rest of the leg?
The exoskeleton is much thinner around the joints.
5.What sex is the crayfish? How do you know?
My crayfish is male because it has a pseudopenis.
6. Why is there so much surface area on the gills of a crayfish?
So that there is a larger surface filtering water and making gas exchange, this makes it a much faster and efficient process
8. Which appendage(s) is used to:
Sense: Compound eyes
Defend: Chelipeds
Mate: Pseudopenis/ Swimmerets
Eat: Maxilla and Maxillipeds
Chew: Mandibles
Move Backwards: Walking legs, Swimmerets and Flipper
Move Forwards: Walking legs
Swimming: Swimmerets and Flipper
9. How are Arthropods more advanced than the other phyla we've looked at so far?
The Arthropods are more advanced having developed; an exoskeleton, and the ability to fly.
10. Why are insects so prolific while crayfish are not?
Since insects are much smaller and have shorter life spans there are more offspring produced rather than fewer offspring since crayfish are much larger and complex. However because of their size and ability to fly (for some) it would seems that insects have the upper hand.
Sense: Compound eyes
Defend: Chelipeds
Mate: Pseudopenis/ Swimmerets
Eat: Maxilla and Maxillipeds
Chew: Mandibles
Move Backwards: Walking legs, Swimmerets and Flipper
Move Forwards: Walking legs
Swimming: Swimmerets and Flipper
9. How are Arthropods more advanced than the other phyla we've looked at so far?
The Arthropods are more advanced having developed; an exoskeleton, and the ability to fly.
10. Why are insects so prolific while crayfish are not?
Since insects are much smaller and have shorter life spans there are more offspring produced rather than fewer offspring since crayfish are much larger and complex. However because of their size and ability to fly (for some) it would seems that insects have the upper hand.
Phylum Echinodermata
Characteristics
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✏ Pentaradial Symmetry
✏ Deuterostomes ✏ Sexual Reproduction ✏ Water Vascular System -> "Circulatory System" ✏ Not segmented ✏ Two Stomachs; Cardiac and Pyloric ✏ Limited Regeneration ✏ Four Classes: 1. Asteroidea -> Ex; Seastars 2. Echinoidea -> Ex; Sea Urchins 3. Holothuroidea -> Ex; Sea Cucumbers 4. Crinoidea -> Ex; Sea Lilies |
The Echinoderms
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* No lab for this unit due to shortage of seastars. Save a sea star!!*
