Lab 9 - Animal Diversity

Lab Objectives

• Compare anatomy of representative animals focusing on similarities and differences in body structures.
• Discuss the impact of molecular studies on traditional phylogenetic trees.
• Analyze relationships between body form and lifestyle/niche of organisms.

Key Concepts

Classification of Animals

• Domain: Eukarya
• Kingdom: Animalia
• Multicellular, heterotrophic organisms

Major Animal Groups

• Parazoa (e.g., sponges) - Simple body forms.
• Eumetazoa (all other animals) - More complex body structures, including radial and bilateral symmetry.

Symmetry and Body Form

• Types of Symmetry:

  • Radial: Parts arranged around a central axis
  • Bilateral: Left and right halves are mirror images
  • Asymmetrical: No apparent symmetry

• Body Cavity Types:

  • Acoelomate: No body cavity, filled with mesoderm.
  • Pseudocoelomate: Body cavity between endoderm and mesoderm.
  • Eucoelomate: Body cavity fully lined with mesoderm.

Tissue Organization

• Different layers of cells organized into tissues.
• Presence of distinctive germ layers during embryonic development.

Circulatory Systems

• Open: Blood flows through coelomic spaces and blood vessels.
• Closed: Blood flows entirely through vessels.

Respiratory Structures

• Gas exchange through skin, gills, lungs, or specialized tracheae.

Nervous System Complexity

• Presence of nerve cords and concentration of nerve tissue into brain regions.

Key Characteristics for Dissecting Organisms

• Identify symmetry, tissue organization, body cavity, circulatory system, respiratory structures, segmentation, and nervous system.