Chordata conclusion
Question one:
1. Phylum Porifera- no body wall layers, no symmetry, no segmented body, no body cavity, a digestive system consisting of many water canals and one exit, no tentacles, antennae, or jointed walking legs, an open circulatory system, and no skeleton. This phylum relies solely on water for the most basic functions of life.
2. Phylum Cnidaria- 2 body wall layers, radial symmetry, no segmented bodies, no body cavity, a gastrovascular cavity with one opening, an open circulatory system, tentacles, no antennae, jointed walking legs or skeleton. cnidarians have a nerve net, and an alternation of generations life cycle with a medusa and polyp stage .
3. Platyhelminthes- 3 body wall layers with bilateral symmetry and an unsegmented body. No true body cavity with a digestive system consisting of a gastrovascular cavity with many openings and an everted pharynx, an open circulatory system, no tentacles, antennae, or jointed walking legs, and no skeleton. This phylum shows the beginning of cephalization with a nerve ladder, auricles, and eye spots.
4. Nematoda- 3 body wall layers with bilateral symmetry, no segments, and a pseudocoelom. They have food tubes with a mouth and anus, an open circulatory system, no tentacles, antennae, jointed walking legs, or skeleton. This phylum consists of parasites and free living nematodes; both highly evolved to their environment.
5. Annelida- 3 body wall layers with bilateral symmetry, simple segmentation, a true coelom, a digestive system with food tubes, a mouth and an anus, a closed circulatory system with no tentacles, antennae, jointed walking legs, or skeleton. Annelids also have setae, 3 hearts, a brain, and a ventral nerve cord as well as a true digestive system.
6. Mollusca- 3 body wall layers, bilateral symmetry, no segmentation, a true coelom, food tubes with a mouth and an anus as well as an open circulatory system (although closed in squid and octopus). Molluscs have tentacles (not all!) but no antennae, jointed walking legs, or skeleton. Molluscs have a shells with a visceral mass, a mantle, and a large ventral muscular foot.
7. Arthropoda- 3 body wall layers with bilateral symmetry, specialized segmentation, a true coelom, food tubes with a mouth and anus, and an open circulatory system. This phylum has no tentacles, but displays antennae, jointed walking legs, and an exoskeleton made of chitin. Arthropods have book lungs, tracheids, and gills as well as a hemocoel and a distinctive head, thorax, and abdomen (a cephalothorax for some).
8. Echinodermata- 3 body wall layers with pentaradial symmetry, no segments, a true coelom, and a water vascular system in replacement of a regular respiratory system. Their digestive system has food tubes with a mouth and an anus as well as two stomachs; the cardiac and the pyloric. This phylum has no tentacles, no antennae, no jointed walking legs, but displays an internal skeleton (endoskeleton) with ossicles.
9. Chordata- This phylum carries all the vertebrates that all share 4 general characteristics; a notochord, a dorsal hollow nerve cord, pharyngeal gill slits, and a muscular, post anal tail. This phylum includes many highly evolved species that are brilliantly adapted to their environment. These species have greatly improved respiratory systems, digestive systems, reproductive systems, excretory systems, circulatory systems etc. This phylum is more evolved in many aspects when compared to the 8 previous phylas classified as invertebrates.
Question two:
I believe that humans are the most adapted to the earth; credited to our highly evolved brain. Although physically, we are often viewed as less superior to other mammals, intellectually, we are able to make up for this; using our brains as a means of adaption and changing to best fit our environment and the situations we find ourselves in. Although there are brilliantly adapted organisms in our world today, we are the only species to have such complex adaptations in many different aspects such as socially and culturally. We have gone past survival adaptations and spiralled into a much more intricate form of evolving over time. We have only viewed these complex adaptations in very few species, and to a much lower degree. It's for these reasons why I believe humans are the most evolved out of all the species.
Question three:
Although my portfolio may suggest that evolution is indeed more than a theory as an overall theme (it convinces me!) , I don't believe it can be used as a "sound piece of evidence", due to the fact that a lot of my information consists of things I've pieced together on my own, without a true source to guarantee a credibility to them. Despite this, I believe that some things I've written have a very fact-based, basic outlook on organisms, and someone viewing it could easily hypothesis how these animals have evolved from each other.
Question one:
1. Phylum Porifera- no body wall layers, no symmetry, no segmented body, no body cavity, a digestive system consisting of many water canals and one exit, no tentacles, antennae, or jointed walking legs, an open circulatory system, and no skeleton. This phylum relies solely on water for the most basic functions of life.
2. Phylum Cnidaria- 2 body wall layers, radial symmetry, no segmented bodies, no body cavity, a gastrovascular cavity with one opening, an open circulatory system, tentacles, no antennae, jointed walking legs or skeleton. cnidarians have a nerve net, and an alternation of generations life cycle with a medusa and polyp stage .
3. Platyhelminthes- 3 body wall layers with bilateral symmetry and an unsegmented body. No true body cavity with a digestive system consisting of a gastrovascular cavity with many openings and an everted pharynx, an open circulatory system, no tentacles, antennae, or jointed walking legs, and no skeleton. This phylum shows the beginning of cephalization with a nerve ladder, auricles, and eye spots.
4. Nematoda- 3 body wall layers with bilateral symmetry, no segments, and a pseudocoelom. They have food tubes with a mouth and anus, an open circulatory system, no tentacles, antennae, jointed walking legs, or skeleton. This phylum consists of parasites and free living nematodes; both highly evolved to their environment.
5. Annelida- 3 body wall layers with bilateral symmetry, simple segmentation, a true coelom, a digestive system with food tubes, a mouth and an anus, a closed circulatory system with no tentacles, antennae, jointed walking legs, or skeleton. Annelids also have setae, 3 hearts, a brain, and a ventral nerve cord as well as a true digestive system.
6. Mollusca- 3 body wall layers, bilateral symmetry, no segmentation, a true coelom, food tubes with a mouth and an anus as well as an open circulatory system (although closed in squid and octopus). Molluscs have tentacles (not all!) but no antennae, jointed walking legs, or skeleton. Molluscs have a shells with a visceral mass, a mantle, and a large ventral muscular foot.
7. Arthropoda- 3 body wall layers with bilateral symmetry, specialized segmentation, a true coelom, food tubes with a mouth and anus, and an open circulatory system. This phylum has no tentacles, but displays antennae, jointed walking legs, and an exoskeleton made of chitin. Arthropods have book lungs, tracheids, and gills as well as a hemocoel and a distinctive head, thorax, and abdomen (a cephalothorax for some).
8. Echinodermata- 3 body wall layers with pentaradial symmetry, no segments, a true coelom, and a water vascular system in replacement of a regular respiratory system. Their digestive system has food tubes with a mouth and an anus as well as two stomachs; the cardiac and the pyloric. This phylum has no tentacles, no antennae, no jointed walking legs, but displays an internal skeleton (endoskeleton) with ossicles.
9. Chordata- This phylum carries all the vertebrates that all share 4 general characteristics; a notochord, a dorsal hollow nerve cord, pharyngeal gill slits, and a muscular, post anal tail. This phylum includes many highly evolved species that are brilliantly adapted to their environment. These species have greatly improved respiratory systems, digestive systems, reproductive systems, excretory systems, circulatory systems etc. This phylum is more evolved in many aspects when compared to the 8 previous phylas classified as invertebrates.
Question two:
I believe that humans are the most adapted to the earth; credited to our highly evolved brain. Although physically, we are often viewed as less superior to other mammals, intellectually, we are able to make up for this; using our brains as a means of adaption and changing to best fit our environment and the situations we find ourselves in. Although there are brilliantly adapted organisms in our world today, we are the only species to have such complex adaptations in many different aspects such as socially and culturally. We have gone past survival adaptations and spiralled into a much more intricate form of evolving over time. We have only viewed these complex adaptations in very few species, and to a much lower degree. It's for these reasons why I believe humans are the most evolved out of all the species.
Question three:
Although my portfolio may suggest that evolution is indeed more than a theory as an overall theme (it convinces me!) , I don't believe it can be used as a "sound piece of evidence", due to the fact that a lot of my information consists of things I've pieced together on my own, without a true source to guarantee a credibility to them. Despite this, I believe that some things I've written have a very fact-based, basic outlook on organisms, and someone viewing it could easily hypothesis how these animals have evolved from each other.