What characteristics are used in classifying animals ? Give an outline classification of the kingdom Animalia.

Explanation

### Step-by-Step Solution:

1. **Introduction to Classification of Animals**:
Animals are classified based on various characteristics that reflect their morphology (form and structure) and developmental patterns.

2. **Key Characteristics Used in Classification**:
- **Level of Symmetry**: This refers to the arrangement of body parts. Animals can be classified into:
- **Radial Symmetry**: Body parts arranged around a central axis (e.g., jellyfish).
...