Instructor: Kelli Roberts
1. Which phyla lack organs? What type of Symmetry do they have? The phyla that lack organs are: Sponges, Jellyfish, Roundworm and the flatworm. The sponges have symmetry and the jellyfish is radial. The roundworm and the flatworm are both bilateral symmetry. 2. List all of the Phyla that show cephalization.
The Phyla that show cephalization are: Platyhelminthes, Nematode, Annelida, Mollusca, Arthropoda, and the Chordata. (esu.edu) 3. Do all organisms on the table have three germ layers (endoderm, ectoderm, and mesoderm)? If not, which phyla have fewer than three germ layers? No, not all organisms on the table have three germ layers such as the sponges. The phyla’s that do have three germ layers are the: Flatworm, roundworm, mollusks, echinoidea, chordates and the arthropods. (Clc.U.C.edu. 1997) 4. One phylum on the table has more species that all the others. State the name of this phylum, and provide several different examples of the species found in the phylum. The phylum that has more species than the others is the Arthropoda. Examples found in the arthropoda are: cockroachs, ants, flies, bees, beetles, and butterflies. (Biology Questions (2003) 5. Fish do not all have the same skeletal structure. Describe the differences among fish from the most primitive to the more advanced type of fish. The primitive fish have more skeletons and the advanced fish have more muscles. (creation wiki, 2007) 6. Describe the three types of mammals based on how their young develop. The three types of mammals based on the how their young develop are: Monotremes, Marsupials, and Placental. The Marsupials developed in a pouch and the Monotremes are egg laying mammals and the Placental are mammals that develop in the womb. (Life 123, 2010)
Three Types of Mammals/Life123. (2010). Retrieved from http://www.life123.com/question/What-Are-T…