Study guide: Animal Kingdom Classification

📋 Course Outline

1. Animal Body-Plan Features
2. Non-Chordate Animal Groups
3. Vertebrate Classes

📖 1. Animal Body-Plan Features

★ Must-know

• Animals may be diploblastic, with two germ layers, or triploblastic, with three germ layers.

• Animals may show radial symmetry, in which body parts are arranged around a central axis, or bilateral symmetry, in which the body can be divided into two equal halves.

• Animals may be acoelomate, pseudocoelomate, or coelomate according to the presence and type of body cavity.

Further detail

• The animal body plan shown includes cellular, tissue, organ, and organ-system levels of organization.

💡 Memory Hook

Radial symmetry radiates around a centre, whereas bilateral symmetry divides the body into two sides.

📖 2. Non-Chordate Animal Groups

★ Must-know

• Cnidarians include Hydra and may have sessile polyp and free-swimming medusa forms.

• Molluscs possess a mantle cavity and a radula, and the diagram associates them with excretion and respiration.

• Hemichordates are characterized by a proboscis and stomochord.

Further detail

📌 Cnidarians may reproduce asexually in the polyp form and sexually in the medusa form.

💡 Memory Hook

Cnidaria → Platyhelminthes → Mollusca → Hemichordata

📖 3. Vertebrate Classes

★ Must-know

📌 Pisces, Amphibia, and Reptilia are shown as poikilothermic or cold-blooded vertebrates, whereas birds and mammals are shown as homeothermic or warm-blooded vertebrates.

• The vertebrate groups shown are:
  • Pisces
  • Amphibia
  • Reptilia
  • birds
  • mammals

Further detail

• The vertebrate diagram identifies gills, a pelvic fin, a tympanum, and a cloaca among the illustrated anatomical features.

💡 Memory Hook

Poikilotherms are cold-blooded, whereas homeotherms are warm-blooded.

📊 Synthesis Tables

Vertebrate Temperature Regulation

Group	Temperature regulation	Examples shown
Poikilotherms	Cold-blooded	Pisces, Amphibia, Reptilia
Homeotherms	Warm-blooded	Birds and mammals