Question

How animals are classified based on symmetry?

Answer 1

Animal Kingdom:

The animal kingdom is the largest kingdom amongst the five kingdoms consisting of all animals. Animals are multicellular eukaryotes; do not possess a cell wall or chlorophyll like plants, and share the same mode of nutrition, that is, the heterotrophic mode.

Symmetry:

Based on symmetry, animals are classified into three types of symmetry:

1. Asymmetry - A symmetry where any plane passing through the central axis does not divide the body into two equal halves is called asymmetry. Example- sponges.
2. Radial symmetry - A symmetry where any plane passing through the central axis divides the body into two equal halves is called radial symmetry. Examples are Coelenterates, ctenophores and echinoderms.
3. Bilateral symmetry - In bilateral symmetry, only a single plane divides the body into two equal halves, e.g. Annelids, Arthropods, Molluscs, etc.