Earthworm Dissection
1) What is the name of the pumping organs of an earthworm?
Earthworms have five aortic arches.
2)In the earthworm, trace the parts of the digestive tract through which food passes.
The food enters through the mouth, to the esophagus to the pharynx. Then travels to the crop and the gizzard, then lastly the gut.
3) Which of the parts of the earthworm’s body that you saw are included in the excretory system?
Nephridia are the excretory organs of the annelid, which filter fluid through the coelom. Solid waste leaves through the anus.
4) Among the earthworm’s structural adaptations are its setae. How do you think the earthworm’s setae make it well adapted to its habitat?
Setae allow an earthworm to move without slipping. They wouldn't be able to move without setae.
5) How is the earthworm’s digestive system adapted for extracting relatively small amounts of food from large amounts of ingested soil?
Since the earthworm has a true coelom with muscle surrounding it, these muscles contract pumping soil through. The crops stores food and the gizzard breaks down the food.
6) What did each germ layer develop into in the earthworm?
Ectoderm- skin and nervous system
Mesoderm- Muscle
Endoderm- Digestive tract
7) What is the function of the nephridium? How does it complete this function?
A nephridium's job is to filter fluid through the coelom. It completes its function by filtering out blood.
8) How is the sandworm similar and different to the earthworm?
Similarities
Both annelids
segmented
have same coelom
Differences
Sandworms live in marine environments
Sandworms have more setae- parapodia (paddlelike)
Sandworms in class polychaeta
9) How is the leech designed to live as an ectoparasite? What are the similarities and differences between the leech and the earthworm?
A leech is designed to be an ectoparasite because it has suckers at both ends of body allowing them to cling to the host. They slice skin with their razor sharp jaws. Leeches release anaesthetises, this makes the host not realize they have been bitten.
Similarities
Both have same coelom
Segmented
Differences
Ectoparasite (Leech)
Freeliving, decomposer (earthworm)
Earthworms have five aortic arches.
2)In the earthworm, trace the parts of the digestive tract through which food passes.
The food enters through the mouth, to the esophagus to the pharynx. Then travels to the crop and the gizzard, then lastly the gut.
3) Which of the parts of the earthworm’s body that you saw are included in the excretory system?
Nephridia are the excretory organs of the annelid, which filter fluid through the coelom. Solid waste leaves through the anus.
4) Among the earthworm’s structural adaptations are its setae. How do you think the earthworm’s setae make it well adapted to its habitat?
Setae allow an earthworm to move without slipping. They wouldn't be able to move without setae.
5) How is the earthworm’s digestive system adapted for extracting relatively small amounts of food from large amounts of ingested soil?
Since the earthworm has a true coelom with muscle surrounding it, these muscles contract pumping soil through. The crops stores food and the gizzard breaks down the food.
6) What did each germ layer develop into in the earthworm?
Ectoderm- skin and nervous system
Mesoderm- Muscle
Endoderm- Digestive tract
7) What is the function of the nephridium? How does it complete this function?
A nephridium's job is to filter fluid through the coelom. It completes its function by filtering out blood.
8) How is the sandworm similar and different to the earthworm?
Similarities
Both annelids
segmented
have same coelom
Differences
Sandworms live in marine environments
Sandworms have more setae- parapodia (paddlelike)
Sandworms in class polychaeta
9) How is the leech designed to live as an ectoparasite? What are the similarities and differences between the leech and the earthworm?
A leech is designed to be an ectoparasite because it has suckers at both ends of body allowing them to cling to the host. They slice skin with their razor sharp jaws. Leeches release anaesthetises, this makes the host not realize they have been bitten.
Similarities
Both have same coelom
Segmented
Differences
Ectoparasite (Leech)
Freeliving, decomposer (earthworm)
Squid Dissection
1.
How are arm and tentacles
similar and different?
Arms and tentacles are similar because they are both derived from the foot and contain sucking disks, which allow them to hold onto their prey. They are different because of their physical appearance. The tentacles are longer where as the arms are short.
2. How are cephalopods similar and different to bivalves?
The similarities between the cephalopods are they both come from the phylum Mollusca. Secondly they are both made up of teh foot, visceral mass, mantle, and they both have either an internal or external shell. The differences are that bivalves are usually sessile, only move using foot if threatened. Bivalves have two shells. Examples of Bivalves are clams, oysters, and scallops. Cephalopods are soft bodied and move quickly. They either have internal shells or none at all. Cephalopods include squid, octopus, and cuttlefish.
3. Was your squid a boy or a girl? How did you determine this?
The squid in our dissection was a boy. We know this because it had a reproductive organ on top. This looked like a white sac and it felt soft. If we had a female the reproductive organ would be on the side, which was yellow and hard.
4. Trace the path of food through your squid.
Squids have a digestive system called a "Tube within a Tube" this means they have separate mouth and anus. The tentacles are used to capture prey and bring the food towards the mouth. The beak and radula, which is a tongue like structure with tiny teeth attached break down the food. The food then moves down to the esophagus then to the stomach, and digestion occurs. The digested food then moves to the anus and out the excurrent siphon.
5. Why are the brachial hearts so close to the gills?
The brachial hearts are close to the gills because while oxygen is entering the blood, carbon dioxide is going the opposite way trying to go from the blood into the water and out the excurrent siphon.
Arms and tentacles are similar because they are both derived from the foot and contain sucking disks, which allow them to hold onto their prey. They are different because of their physical appearance. The tentacles are longer where as the arms are short.
2. How are cephalopods similar and different to bivalves?
The similarities between the cephalopods are they both come from the phylum Mollusca. Secondly they are both made up of teh foot, visceral mass, mantle, and they both have either an internal or external shell. The differences are that bivalves are usually sessile, only move using foot if threatened. Bivalves have two shells. Examples of Bivalves are clams, oysters, and scallops. Cephalopods are soft bodied and move quickly. They either have internal shells or none at all. Cephalopods include squid, octopus, and cuttlefish.
3. Was your squid a boy or a girl? How did you determine this?
The squid in our dissection was a boy. We know this because it had a reproductive organ on top. This looked like a white sac and it felt soft. If we had a female the reproductive organ would be on the side, which was yellow and hard.
4. Trace the path of food through your squid.
Squids have a digestive system called a "Tube within a Tube" this means they have separate mouth and anus. The tentacles are used to capture prey and bring the food towards the mouth. The beak and radula, which is a tongue like structure with tiny teeth attached break down the food. The food then moves down to the esophagus then to the stomach, and digestion occurs. The digested food then moves to the anus and out the excurrent siphon.
5. Why are the brachial hearts so close to the gills?
The brachial hearts are close to the gills because while oxygen is entering the blood, carbon dioxide is going the opposite way trying to go from the blood into the water and out the excurrent siphon.
Clayfish Dissection
1.
How many pairs of
appendages did your crayfish have?
Our crayfish has eight pairs of appendages.
2. Label the following on the diagram:
Pictures above
3. How does the thickness of the exoskeleton around the joint compare with the thickness around the rest of the leg?
The thickness around the joint is relatively thin compared to the thickness around the rest of the leg. This being because if the exoskeleton was here the organism would not be able to move properly.
4. Circle the correct sex of your crayfish.
My crayfish is a male / female. I know this because:
The male crayfish have a pair of pseudopenises where as females have feathery swimmeretes.
5. Why is there so much surface area on the gills of a crayfish?
The greater amount of surface are the more oxygen a crayfish can take in.
6. Draw the digestive system and label the structures food would pass through:
Food enters the crayfish through its mouth. The food travels down the esophagus into the stomach. Leaves the stomach and enters the intestine. Digestive waste leaves through the anus. The cellular waste will be filtered out by green glands.
7. Which appendage(s) is used to:
- sense: Antennae, Antennules, Compound eyes
- defend: Chelipeds
- mate: pseduopenises (Male), Swimmerettes (Female)
- eat: Chelipeds
- chew: Mandibles
- move backwards: Tail
- move forwards: Walking legs
- swim: Swimmerettes
8. How are arthropods more advanced than the other phyla that we have looked at thus far?
Arthropods are more advanced than the other phyla we have looked at thus far because they have specialized appendages and they are segmented. Not only this but they have what is called an exoskeleton, which can provide protection. In the phylum Arthropods Class Insecta is able to fly. Arthropods also have more developed circulatory and respiratory (book lungs/gills, tracheal tubes) systems.
9. Why are the insects so prolific while the crayfish are not?
Insects are so prolific because of their size they don't eat much and they have a short life span. Class Insecta are also able to take flight and have adapted their exoskeleton to provide Camouflage for them. Not only this they have well developed senses and have certain niches, which decreases competition.
Our crayfish has eight pairs of appendages.
2. Label the following on the diagram:
Pictures above
3. How does the thickness of the exoskeleton around the joint compare with the thickness around the rest of the leg?
The thickness around the joint is relatively thin compared to the thickness around the rest of the leg. This being because if the exoskeleton was here the organism would not be able to move properly.
4. Circle the correct sex of your crayfish.
My crayfish is a male / female. I know this because:
The male crayfish have a pair of pseudopenises where as females have feathery swimmeretes.
5. Why is there so much surface area on the gills of a crayfish?
The greater amount of surface are the more oxygen a crayfish can take in.
6. Draw the digestive system and label the structures food would pass through:
Food enters the crayfish through its mouth. The food travels down the esophagus into the stomach. Leaves the stomach and enters the intestine. Digestive waste leaves through the anus. The cellular waste will be filtered out by green glands.
7. Which appendage(s) is used to:
- sense: Antennae, Antennules, Compound eyes
- defend: Chelipeds
- mate: pseduopenises (Male), Swimmerettes (Female)
- eat: Chelipeds
- chew: Mandibles
- move backwards: Tail
- move forwards: Walking legs
- swim: Swimmerettes
8. How are arthropods more advanced than the other phyla that we have looked at thus far?
Arthropods are more advanced than the other phyla we have looked at thus far because they have specialized appendages and they are segmented. Not only this but they have what is called an exoskeleton, which can provide protection. In the phylum Arthropods Class Insecta is able to fly. Arthropods also have more developed circulatory and respiratory (book lungs/gills, tracheal tubes) systems.
9. Why are the insects so prolific while the crayfish are not?
Insects are so prolific because of their size they don't eat much and they have a short life span. Class Insecta are also able to take flight and have adapted their exoskeleton to provide Camouflage for them. Not only this they have well developed senses and have certain niches, which decreases competition.
Sea Star Dissection
1. What type of symmetry did your sea star have?
Penta-Radial symmetry
2. How many arms or rays does your sea star have?
My sea star had five arms.
3. Label the central disc, arms, spines, eyespot and madreporite on the diagram below.
Picture below
4. What is the upper surface of the starfish called?
Aboral surface.
5. What is the lower surface of the starfish called?
Oral surface
6. Label the oral spines, mouth, ambulacral groove and tube feet on the diagram below
Picture Below
7. Label pyloric caeca, stomach, central disc, gonads, ampulla and ossicles in the diagram below:
Picture Below
8. Label the lateral canal, ring canal, stone canal and madreporite in the diagram below:
Picture Below
9. Colour an arrow on the diagram above tracing the path that water takes when it enters and moves through the sea star.
Water enters the water vascular system through the Madreporite. The water travels down the stone canal, then into the ring canal, where it enters five radial canals. The water then hits the ampullae, these squeeze water into tube feet.
10. On which surface are these parts of a sea star visible:
a. Mouth - Oral Surface
b. Madreporite - Aboral Surface
c. Suckers - Oral Surface
d. Oral spines - Oral Surface
e. Eyespots - End of arms
d. Ambulcaral groove – Oral Surface
11. What part of the tube foot creates suction to open clams whenever the sea star feeds?
The sucker part of the tube feet creates suction to open clams.
12. Why do the gonads sometimes appear larger?
The gonads appear larger when it is reproductive season. However, at the time of our dissection it was not reproductive season so the gonads in our star fish appeared smaller.
13. What type of skeleton, endoskeleton or exoskeleton, does the sea star have?
Sea Stars have an endoskeleton.
14. What bony plates make up its skeleton?
Calcarious plates make up the semi flexible endoskeleton.
15. What is the function of the pyloric caeca?
Pyloric Caeca contains digestive enzymes, which help absorb the nutrients from the food and digest the food.
16. Where is the stomach of a sea star located? What can the sea star do with its stomach when feeding on clams & oysters?
The stomach of the sea star is located on the oral surface. When feeding on clams and oysters a star fish will pour its stomach out of its mouth as well as enzymes and partially digest its food. It will then bring the stomach back in with the partially digested food.
Penta-Radial symmetry
2. How many arms or rays does your sea star have?
My sea star had five arms.
3. Label the central disc, arms, spines, eyespot and madreporite on the diagram below.
Picture below
4. What is the upper surface of the starfish called?
Aboral surface.
5. What is the lower surface of the starfish called?
Oral surface
6. Label the oral spines, mouth, ambulacral groove and tube feet on the diagram below
Picture Below
7. Label pyloric caeca, stomach, central disc, gonads, ampulla and ossicles in the diagram below:
Picture Below
8. Label the lateral canal, ring canal, stone canal and madreporite in the diagram below:
Picture Below
9. Colour an arrow on the diagram above tracing the path that water takes when it enters and moves through the sea star.
Water enters the water vascular system through the Madreporite. The water travels down the stone canal, then into the ring canal, where it enters five radial canals. The water then hits the ampullae, these squeeze water into tube feet.
10. On which surface are these parts of a sea star visible:
a. Mouth - Oral Surface
b. Madreporite - Aboral Surface
c. Suckers - Oral Surface
d. Oral spines - Oral Surface
e. Eyespots - End of arms
d. Ambulcaral groove – Oral Surface
11. What part of the tube foot creates suction to open clams whenever the sea star feeds?
The sucker part of the tube feet creates suction to open clams.
12. Why do the gonads sometimes appear larger?
The gonads appear larger when it is reproductive season. However, at the time of our dissection it was not reproductive season so the gonads in our star fish appeared smaller.
13. What type of skeleton, endoskeleton or exoskeleton, does the sea star have?
Sea Stars have an endoskeleton.
14. What bony plates make up its skeleton?
Calcarious plates make up the semi flexible endoskeleton.
15. What is the function of the pyloric caeca?
Pyloric Caeca contains digestive enzymes, which help absorb the nutrients from the food and digest the food.
16. Where is the stomach of a sea star located? What can the sea star do with its stomach when feeding on clams & oysters?
The stomach of the sea star is located on the oral surface. When feeding on clams and oysters a star fish will pour its stomach out of its mouth as well as enzymes and partially digest its food. It will then bring the stomach back in with the partially digested food.