Unit 1

The first unit includes important background material on topics such as evolution and classification.

It also includes the Protozoa and some of the Invertebrate Animals.

Most animals are invertebrates. Only part of the Phylum Chordata are vertebrates.

The invertebrates covered in Unit 1 include:

	Phylum Porifera (sponges)
	The Radiates: Phyla Cnidaria and Ctenophora
	The Acoelomates: Phylum Platyhelminthes
	The Pseudocoelomates: Phyla Nematoda, Rotifera and others.