Animal Kingdom (Abyss of Classification)

Introduction

• Kingdom Plantae: Study of plants.
• Kingdom Animalia: Study of animals.

Classification

• Meaning of Classification: Creating categories of organisms based on division and identification.
• Importance: Recognizing the characteristics of animals and categorizing them accordingly.

Characteristics of Animal Kingdom

• Heterotrophic Nutrition: Animals obtain nutrition by consuming other organisms.
• Mobility: Animals are mostly mobile.
• Sensory Organs: Most animals have eyes, ears, etc.
• Cell Structure: Multicellular and eukaryotic.

Basis of Division

• Mobility and Sensory: Animals divided based on mobility and sensory organs.
• Reproductive System: Unisexual and bisexual.

Multicellular and Eukaryotic Traits

• Examples: Porifera (sponges), Coelenterata, Platyhelminthes, etc.

Levels of Classification

1. Cell Level
   • Example: Porifera (sponges)
2. Tissue Level
   • Example: Coelenterata (jellyfish)
3. Organ Level
   • Example: Platyhelminthes
4. Organ System Level
   • Advanced organisms such as vertebrates

Importance of Symmetry

• Asymmetrical: Found in sponges.
• Radial Symmetry: Found in Coelenterata and adult Echinoderms.
• Bilateral Symmetry: Found in Platyhelminthes, Annelida, etc.

Germ Layers (Cellular Construction)

• Diploblastic: Two layers (ectoderm and endoderm)
• Triploblastic: Three layers (ectoderm, mesoderm, endoderm)

Types of Coelom

1. Acoelomate: No coelom (Platyhelminthes)
2. Pseudocoelomate: False coelom (Aschelminthes)
3. Eucoelomate: True coelom (from Annelida to Chordata)

Digestive System

• Incomplete: Single opening (Coelenterata)
• Complete: Both mouth and anus present.

Circulatory System

• Open Circulatory System: Example: Arthropoda
• Closed Circulatory System: Example: Chordata

Reproductive System

• Unisexual (single sex)
• Bisexual (both sexes)

Segmentation

• True: Inner and outer segmentation (Annelida)
• False: False segmentation (Platyhelminthes)

Notochord

• Function: Provides support.
• Presence: Found in Chordates, not in non-Chordates.

Key Understandings

• Classification forms the basis for understanding animals.
• Important kingdoms and their differences.