First Term - Compiled

• What type of symmetry do cnidarian polyps have?

  Radial symmetry
• How many major phyla of living multicellular animals do zoologists recognize?

  34 major phyla
• When did survivors of about 100 phyla appear?

  600 million years ago during the Cambrian explosion
• What caused all major body plans to evolve within a few million years?

  Selection and adaptation
• What does the basic uniformity of life derive from?

  Common ancestry and similar cellular construction
• How is life organized in terms of complexity?

  From simple to complex
• What are the five grades of organization in animals?

  1. Protoplasmic Grade: Unicellular organisms (e.g., Paramecium)
  2. Cellular Grade: Cells in larger aggregates
  3. Tissue Grade: Cells in patterns or layers
  4. Organ Grade: Aggregated tissues form organs (e.g., flatworms)
  5. System Grade: Several organs work together (e.g., annelids, arthropods)
• What type of symmetry do sponges exhibit?

  Asymmetry
• What is the anterior region of bilaterally symmetrical animals?

  Head end
• What is the dorsal side of an animal?

  Back side
• What does the ventral side refer to?

  Belly side
• What does the medial position indicate?

  Midline
• What does the term distal refer to?

  Farther from middle
• What does proximal mean?

  Nearer to middle
• What are the three planes of the body?

  1. Frontal (coronal) plane: Divides into dorsal and ventral halves
  2. Sagittal plane: Divides into right and left halves
  3. Transverse (cross-section) plane: Divides into anterior and posterior halves
• What is the purpose of body cavities?

  To cushion and protect internal organs
• What is an acoelomate?

  No body cavity
• What is a pseudocoelomate?

  Partial body cavity
• What is a coelomate?

  True body cavity
• What does the endoderm layer form?

  Gut lining
• What does the ectoderm layer represent?

  Outer layer
• What is the mesoderm layer?

  Middle layer
• How do protostomes differ from deuterostomes in mesoderm formation?

  Protostomes form mesoderm near the blastopore
• How do deuterostomes form mesoderm?

  From gut lining
• What is a dichotomous key?

  • A tool for identifying organisms
  • Divided into two parts (Greek: dikhótomos)
  • Each step presents two distinct choices
• What are the components of a dichotomous key?

  • Couplets: Pairs of contrasting statements
  • Lead: Statements that make up a couplet
• What are the types of dichotomous keys based on structure?

  1. Indented Key: Uses indentation for hierarchy
  2. Bracketed Key: Uses numbers and brackets
  3. Branching Key: Tree-like diagram for choices
  4. Pictorial Key: Uses images for identification
• What are the rules for making taxonomic keys?

  • Lead word of each couplet should be the same
  • No two consecutive couplets should start with the same word(s)
  • Leads should express contradictory statements
  • Use positive statements
  • Avoid overlapping ranges or vague generalities
  • Use observable features
  • Avoid geographical location as the only character
  • Show group relationships
• What are the types of dichotomous keys based on function?

  1. Diagnostic Keys: Focus on identifying organisms
  2. Synoptic Keys: Reflect scientific classification
• What are the types of dichotomous keys based on structure (repeated)?

  1. Indented Key: Uses indentation for hierarchy
  2. Bracketed Key: Uses numbers and brackets
  3. Circular Key: Diagram with branching choices
  4. Pictorial Key: Uses images for identification
• Who proposed the Two-Kingdom System of classification?

  Carolus Linnaeus
• Who proposed the Three-Kingdom System of classification?

  Ernst Haeckel
• Who proposed the Four-Kingdom System of classification?

  H.F. Copeland
• Who proposed the Five-Kingdom System of classification?

  R.H. Whittaker
• Who proposed the Six-Kingdom System of classification?

  Carl Woese
• What are the three domains of life?

  1. Bacteria (Eubacteria)
  2. Archaea (Archaebacteria)
  3. Eukarya (Protista, Fungi, Plantae, Animalia)
• What is the format of binomial nomenclature?

  Genus species format
• What is the purpose of scientific names?

  Provide universal classification and eliminate confusion
• What are the types of phylogenetic trees?

  1. Phylogram: Scaled tree showing divergence
  2. Cladogram: Based on shared traits
  3. Phenogram: Shows similarity
• What are the definitions of monophyletic, polyphyletic, and paraphyletic groups?

  • Monophyletic: Common ancestor and all descendants
  • Polyphyletic: Groups without a common ancestor
  • Paraphyletic: Common ancestor but not all descendants