What are the characteristics of metazoans?

These common characteristics include multi-cellularity, specialization of tissues, movement, heterotrophy, and sexual reproduction.

What defines a Metazoa?

Definition of metazoan : any of a group (Metazoa) that comprises all animals having the body composed of cells differentiated into tissues and organs and usually a digestive cavity lined with specialized cells.

What are the two groups of Metazoa?

In 1874, Ernst Haeckel divided the animal kingdom into two subkingdoms: Metazoa (multicellular animals, with five phyla: coelenterates, echinoderms, articulates, molluscs, and vertebrates) and Protozoa (single-celled animals), including a sixth animal phylum, sponges.

What are metazoans classified?

Metazoa and its classification Metazoa (animals) represent a group of multicellular eukaryotes (Haeckel, 1874) and constitute a monophyletic clade with heterotrophic organisms. They are believed to have diversified around the beginning of the Cambrian period (∼543 million years ago).

Why are animals called metazoans?

Any of the animals belonging to the subkingdom Metazoa, having a body made up of differentiated cells arranged in tissues and organs. All multicellular animals besides sponges are metazoans.

What is colonial theory of Metazoa?

The theory of cellularization, also known as the syncytial theory or ciliate-acoel theory, is a theory to explain the origin of Metazoa. The idea was proposed by Hadži and Hanson. The cellularization theory states that metazoans evolved from a unicellular ciliate with multiple nuclei that went through cellularization.

What is the difference between protozoa and Metazoa?

The main difference between protozoans and metazoans is that protozoans are unicellular, whereas metazoans are multicellular. Protozoans are animal-like protists and are believed to be primitive types of animals. There is no division of labour as the single cell performs all the biological functions in protozoans.

What is Metazoa in microbiology?

Microbial metazoa are operationally defined as multicellular eukaryote species within the Animalia exhibiting a body size of <1 mm in length.

What is protozoan metazoan?

Protozoa is a group of unicellular eukaryotes that are either free-living in the environment or parasitic on plants or animals. They make up the kingdom Protista. In contrast, Metazoa is a group of multicellular animals. The two main types of metazoans are vertebrates and invertebrates.