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31 Cards in this Set

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  • Back
What are the unique characteristics of animals?
Heterotrophic, Multicellular, Active Movement, Diverse Form and Habitat, Sexual Reproduction, Embryonic Development, Unique Tissues, and the Lack of Cell Walls
Ninety-nine percent of animals are (invertebrates/vertebrates).
In embryonic development, what is a morula? What is a blastula?
A morula is a solid ball of cells. A blastula is the hollow ball of cells.
When the blastula folds inward, what is formed? What is the embryo called at this phase of development?
A Blastopore. The Gastrula.
What two unique animal tissues are associated with movement?
Muscle and Nervous Tissues.
What are the two main branches of the animal kingdom? What is the difference between them?
Parazoa("beside animals") and Eumetazoa("true animals"). Parazoa lack symetry, tissues, and organs.
What are the two main branches of Eumetazoans? How are the branches embryonically different?
Radiata(radial symetry) and Bilateria(bilateral symmetry). Radiata are diploblastic (no mesoderm) and Bilateria are triploblastic (mesoderm).
What is the primitive gut cavity in an embryo?
The Archenteron.
What were the Five Key Transitions in Body Plan?
1.Evolution of Tissues, 2. of Bilateral Symmetry, 3. of Body Cavities, 4. of Deuterostome Development, 5. of Segmentation
What is radial symmetry? Bilateral symmetry?
Symmetry around an axis. Symmetry across a plane.
What relative locations does bilateral symmetry provide?
Dorsal(top), Ventral(bottom), Anterior(front), Posterior(back).
What are the planes of a bilateral organism?
Sagittal (between the eyes), Frontal (down the sides), Transverse (around the hips).
What are the three embryonic tissues of bilateral eumetazoans?
Ectoderm, Endoderm, and Mesoderm.
What are the three basic bilateral body plans?
Acoelomate(no body cavity), Pseudocoelomate(pseudocoel), Coelomate(coelom)
What is the difference between the pseudocoel and coelom?
The pseudocoel exists between the mesoderm and endoderm. The coelom is entirely within mesoderm.
What is a circulatory system?
A network of vessels that carry fluids through the body.
What is the difference between open and closed circulatory systems?
Open ones allow blood to mix with body fluid. Closed ones isolate the blood in vessels continuously.
What categories are bilaterians divided into according to embryonic development?
Protostomes(blastopore forms mouth), and Deuterostomes(blastopore forms anus).
Which phyla are protostomes? Which are deuterostomes?
Flatworms, nematodes, mollusks, annelids, and arthropods are protostomes. Echinoderms and chordates are deuterostomes.
How else are protostomes and deuterostomes different?
Protostomes perform spiral cleavage, deuterostomes perform radial cleavage. Protostomes use deteminate development, deuterostomes use indeterminate development.
What is segmentation? What is it also known as? Why is it beneficial?
A body plan with successive identical segments. Metamerism. It improves locomotion and provides a failsafe for damaged organs.
What is the name for the process of a head and brain area developing from evolution?
What phyla exhibit segmentation?
Annelids, Arthropods, and Chordates.
What is an example of an organism that does not fit well with current taxonomic organization?
What is molecular systematics?
The use of RNA and DNA sequences in order to organize organisms taxonomically instead of by structural characteristics.
Do taxonomists believe that parazoans and eumetazoans stem from a single common ancestor or several ancestors?
A single common ancestor.
What are the three hypotheses for the origin of animals?
The Multinucleate Hypothesis(multinuclear protist ancestor), Colonial Flagellate Hypothesis (flagellated protist ancestor), and the Polyphyletic Origin Hypothesis (parazoans and eumetazoans evolved independently)
Which hypothesis is the most favored by molecular systematics?
The Colonial Flagellate Hypothesis.
What was the Cambrian Explosion?
The period of very rapid diversification of organisms during the Cambrian period.
What is evo-devo?
A field of biology that combines evolutionary and developmental biology.
Who are you going to vote for MHA president?
Robert Fromm.