Animal Diveritry, Flatworm, Clam, Earthworm, and Hydrazoan

Foundations of Metazoan Taxonomy and Biological Classification

General Introduction Questions

  • 1. To what domain do Animals belong?

    • Answer: Animals belong to the domain Eukarya.

  • 2. Animals belong to what supergroup (According to the lab intro)?

    • Answer: They belong to the supergroup Opisthokonta.

  • 3. All animals belong to Clade Metazoa, what two characteristics do they have?

    • Answer: They are multicellular and heterotrophic.

  • 4. Based on a whole bunch of evidence, Clade Metazoa has been divided into two major groups: Phylum __________________ and Clade________________

    • Answer: Phylum Porifera and Clade Eumetazoa.

  • 5. True animals (Eumetazoa) are further distinguished based several other features.

    • a. Symmetry – What two types of symmetry?

      • Answer: Radial symmetry and bilateral symmetry.

    • b. Germ layers: (list the 3 types)

      • Answer: Ectoderm, mesoderm, and endoderm.

  • 6. Clade Bilateria includes all animals with Bilateral symmetry, which are divided further into 3 clades: What are the 3 clades and list 2 examples of phyla included in each clade. (Use Figure 1 from the Introduction).

    • Answer:

      • a. Deuterostomia: Phylum Echinodermata and Phylum Chordata.

      • b. Lophotrochozoa: Phylum Platyhelminthes and Phylum Mollusca (or Annelida).

      • c. Ecdysozoa: Phylum Nematoda and Phylum Arthropoda.

  • 7. What is one of the characteristics of organisms placed into clade Lophotrochozoa? (Hint: type of larvae)

    • Answer: They possess a developmental stage called a trochophore larva.

  • 8. Match the following definitions with the associated body cavity: (Fig. 2 from Intro. )

    • a. no body cavity = _______________________

      • Answer: Acoelomate.

    • b. cavity present between the mesoderm and endoderm = __________________

      • Answer: Pseudocoelomate.

    • c. body cavity is entirely enclosed by mesoderm ______________________

      • Answer: Coelomate.

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Exercise-Specific Information

Exercise 1:

  • What phylum?

    • Answer: Cnidaria.

  • Common Name: Hydrozoan

  • Genus Name:

    • Answer: Hydra.

Exercise 2:

  • To what clade of bilateral animals does this organism belong?

    • Answer: Lophotrochozoa.

  • What phylum?

    • Answer: Platyhelminthes.

  • Common Name: Planarian

  • Genus Name:

    • Answer: Dugesia.

Exercise 3:

  • To what clade of bilateral animals does this organism belong?

    • Answer: Lophotrochozoa.

  • What phylum?

    • Answer: Mollusca.

  • Common Name: Clam

  • Animal Diversity I: Post-Lab Questions

    1. What is the clade of TRUE animals?

      • Answer: The clade of true animals is Eumetazoa.

    2. What characteristic is required for an organism to be considered a true animal?

      • Answer: True animals (Eumetazoans) are distinguished by having cells organized into well-defined tissue layers.

    3. How many tissues (germ layers) do cnidarians have? Name them.

      • Answer: They have two tissue layers (they are diploblastic): the endoderm and the ectoderm.

    4. What are the two main body forms of cnidarians? What form is Hydra?

      • Answer: The two main body forms are the medusa (jellyfish) stage and the polyp (attached) stage. Hydra is a polyp.

    5. Cnidarians capture their prey with the use of __________________________

      • Answer: Nematocysts (stinging elements located within cells called cnidocytes).

    6. What Clade of Bilateral animals do flatworms and clams belong?

      • Answer: They belong to the clade Lophotrochozoa.

    7. Are flatworms like Dugesia Diploblastic or Triploblastic?

      • Answer: They are triploblastic.

    8. Flatworms are _____________________, meaning they lack a body cavity.

      • Answer: Acoelomate.

    9. What type of cells do flatworms use for excretion?

      • Answer: They use flame cells (also known as protonephridia).

    10. Do Hydra and Dugesia have an incomplete or complete digestive system?

      • Answer: Both have an incomplete digestive system, meaning they have a digestive cavity with only one opening that serves as both the mouth and the anus.


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    Clam Dissection

    1. List the 4 basic features of the mollusc body plan.

      • Answer: 1) A hard shell, 2) a mantle, 3) a visceral mass, and 4) a muscular foot.

    2. Are clams’ protostomes or deuterostomes?

      • Answer: They are protostomes (belonging to the clade Lophotrochozoa).

    3. Describe the directional position of the Umbo.

      • Answer: The umbo is located dorsally (on the top near the hinge) and is displaced anteriorly (toward the front).

    4. The two shells of the clam are called ________________________________________

      • Answer: Valves.

    5. What is the function of the mantle?

      • Answer: The mantle secretes the shell.

    6. What are the openings of a clam’s heart called?

      • Answer: They are called ostia.

    7. The molluscs _________________ is reduced to the pericardial chamber.

      • Answer: Coelom (a "true coelom").

    8. The oldest part of a clam's shell is called the ___________________

      • Answer: Umbo.

    9. What is the purpose of the labial palps?

      • Answer: They guide and filter food into the clam's mouth.