Classification of the Animal Kingdom

Classification of the Animal Kingdom

• Kingdom Animalia is divided into several groups based on characteristics and evolutionary relationships
• The main classification categories are:
  1. Domain: Eukarya (eukaryotic cells)
  2. Kingdom: Animalia (multicellular, eukaryotic, heterotrophic)
  3. Phylum (or Division in some classifications): 35-40 phyla, each representing a distinct body structure
  4. Class: groups of related phyla
  5. Order: groups of related classes
  6. Family: groups of related orders
  7. Genus: groups of related families
  8. Species: the most specific classification unit

Characteristics of Animals

• Multicellularity: composed of multiple cells
• Eukaryotic cells: cells with true nuclei and membrane-bound organelles
• Heterotrophy: obtain energy by consuming other organisms or organic matter
• Mobility: ability to move, although some species have limited or no mobility
• Response to stimuli: ability to respond to environmental stimuli
• Growth and development: ability to grow and develop from embryos to mature individuals

Body Structures and Symmetry

• Radial symmetry: body parts arranged around a central axis (e.g., starfish, sea urchins)
• Bilateral symmetry: body parts arranged around a central axis with mirror-image symmetry (e.g., humans, insects)
• Body cavities: fluid-filled spaces within the body (e.g., coelom, pseudocoelom)
• Body layers: three primary layers: ectoderm, endoderm, and mesoderm

Diversity of Animal Life

• Invertebrates: animals without backbones (e.g., insects, mollusks, echinoderms)
• Vertebrates: animals with backbones (e.g., fish, amphibians, reptiles, birds, mammals)
• Water-dwelling animals: aquatic animals (e.g., fish, marine mammals)
• Land-dwelling animals: terrestrial animals (e.g., insects, reptiles, mammals)
• Flying animals: animals capable of flight (e.g., insects, birds, bats)

Classification of the Animal Kingdom

• Kingdom Animalia is divided into groups based on characteristics and evolutionary relationships
• The main classification categories are: Domain, Kingdom, Phylum, Class, Order, Family, Genus, and Species
• Domain Eukarya is characterized by eukaryotic cells
• Kingdom Animalia is characterized by being multicellular, eukaryotic, and heterotrophic

Characteristics of Animals

• Multicellularity is a characteristic of animals, composed of multiple cells
• Eukaryotic cells have true nuclei and membrane-bound organelles
• Heterotrophy is the ability to obtain energy by consuming other organisms or organic matter
• Mobility is the ability to move, although some species have limited or no mobility
• Response to stimuli is the ability to respond to environmental stimuli
• Growth and development is the ability to grow and develop from embryos to mature individuals

Body Structures and Symmetry

• Radial symmetry is a body structure where parts are arranged around a central axis
• Bilateral symmetry is a body structure where parts are arranged around a central axis with mirror-image symmetry
• Body cavities are fluid-filled spaces within the body, such as coelom or pseudocoelom
• Body layers are three primary layers: ectoderm, endoderm, and mesoderm

Diversity of Animal Life

• Invertebrates are animals without backbones, such as insects, mollusks, and echinoderms
• Vertebrates are animals with backbones, such as fish, amphibians, reptiles, birds, and mammals
• Water-dwelling animals, such as fish and marine mammals, live in aquatic environments
• Land-dwelling animals, such as insects, reptiles, and mammals, live in terrestrial environments
• Flying animals, such as insects, birds, and bats, are capable of flight

Learn about the classification of the animal kingdom, from domain to order, and understand the characteristics and evolutionary relationships that define each group.