Phylum Chordata
Phylum chordata has the characteristics of having a tough, flexible nerve cord. Some organisms in this group will use only that as their primary body support. Others will have the nerve cord surrounded by vertibra which are segments of bone arranged into a backbone. Then we will completely leave the topic of phylum chordata for two modules while we explore kingdom Plantae. In module 16 we will return to the phylum chordata to explore reptiles and mammals.
Lecture 1: Phylum Chrodata and Subphylums Urochordata, Cephalochordata, and Vertibrata
All of the organisms in phylum chordata will have a strong nerve cord, but not all of them will have bones. All of the organisms in lecture 1 will be of this type. The sea squirt is a particularly interesting example of subphylum urochordata and we will go in to a bit more detail on them than some of the other organisms in today's study.
Under our subtopic for subphylum vertibrata we will go in to some of the characteristics that mark this category:
We will also be talking about the circulatory system. Students that would like to go in to more depth than we are able to cover as one subtopic is a lecture day may like to explore the circulatory system info on the Anatomy and Physiology page - hyperlink to it here.
Under our subtopic for subphylum vertibrata we will go in to some of the characteristics that mark this category:
- Complex Nervous Systems
- Closed Circulatory Systems
- Endoskeleton
- Reproductive System
We will also be talking about the circulatory system. Students that would like to go in to more depth than we are able to cover as one subtopic is a lecture day may like to explore the circulatory system info on the Anatomy and Physiology page - hyperlink to it here.
Lecture 2: Class Agnatha and class Chrondichthyes
In today's lecture we will talk about class agnatha (jawless fish) with a focus on the lamprey eel.
We will also talk about class Chrondichtheyes - cartilage fish. The major examples from this class that we will go in to some detail on are sharks, skates, and rays.
We will also talk about class Chrondichtheyes - cartilage fish. The major examples from this class that we will go in to some detail on are sharks, skates, and rays.
Lecture 3 and 4: Classes Osteichthyes and Amphibia
These two lectures go in to a good bit of depth and also include dissections, so they have topic pages all to themselves. Look for them under the Biology/Kingdom navigational tabs for the site or click ...
Preparing for the Labs
Two dissections occur in this module. We will be doing the perch dissection in the online classroom via webcam on Thursday and the normal lab day on the second Tuesday of the module will be for the frog dissection. Remember that the live, webcam labs are not the time when the students should be doing their dissections. They will be learning how at that time, but should do the dissections on a non-online class day so that they will feel that they have the time to explore.
If you have a microscope, be sure to take the time to look closely at the fish gills and scales. The fish and frog’s tongue and the frog’s skin (look at the skin under the jaw in particular) can be very interesting.
If you do the perch dissection and you have a large specimen (most of the time they are larger than the dissection pan), you may find that dissection scissors are not powerful enough to go through the operculum. I have actually used tin snips for that task because the bone can be pretty strong.
A word of warning: Most of the specimens had very low odor, but expect the fish dissection to have the characteristic fish smell. I have actually planned a fish meal for the family meal when we have had a fish dissection in the household because the smell of perch while eating beef or chicken just doesn’t work. hehe. Remember that labs are optional in the course, so if you want to skip this smelly dissection, feel free to. :0)
If your student loves science and animals, you may want to consider getting a tadpole science kit. You will get tadpole eggs and get to watch them go through the frog lifecycle. It is quite fascinating.
If you have a microscope, be sure to take the time to look closely at the fish gills and scales. The fish and frog’s tongue and the frog’s skin (look at the skin under the jaw in particular) can be very interesting.
If you do the perch dissection and you have a large specimen (most of the time they are larger than the dissection pan), you may find that dissection scissors are not powerful enough to go through the operculum. I have actually used tin snips for that task because the bone can be pretty strong.
A word of warning: Most of the specimens had very low odor, but expect the fish dissection to have the characteristic fish smell. I have actually planned a fish meal for the family meal when we have had a fish dissection in the household because the smell of perch while eating beef or chicken just doesn’t work. hehe. Remember that labs are optional in the course, so if you want to skip this smelly dissection, feel free to. :0)
If your student loves science and animals, you may want to consider getting a tadpole science kit. You will get tadpole eggs and get to watch them go through the frog lifecycle. It is quite fascinating.