Chapter 30.1, Problem 2R

Summary Introduction

To review:

The differentiation between radial symmetry and bilateral symmetry, protostome and deuterostome, and diploblastic and triploblastic.

Introduction:

Symmetry is defined as the repetitive body parts of plants and animals in a very ordered fashion. Different types of symmetry are exhibited by animals, such as asymmetry, radial, biradial, bilateral, and spherical. Depending on embryonic development, metazoans can be differentiated into protostomes and deuterostomes.

Protostomes are primarily primitive invertebrates, whereas deuterostomes include echinoderms and chordates. Germ layers are primarily layers of cells that are formed during embryogenesis. Some of the organisms have two germ layers and some have three and are diploblastic and triploblastic, respectively.