Ch. 22 Animals

What is Parazoa?

Simple multicellular organisms like sponges that lack tissues and organs.

What are Eumetazoa?

Animals that have definite shape, symmetry, and tissues mostly organized into organ systems.

What is Radiata?

Radial symmetry that has two embryonic layers.

What is Bilateria?

Bilaterial symmetry that has three embryonic layers.

Who has Tissues?

Only Eumetazoa has tissues not Parazoa.

What is Radial Symmetry?

A body plan in which all parts of the body are arranged around a central axis.

What is Bilateral Symmetry?

A body plan with distinct right and left halves that are mirror images of each other.

What is a Body Cavity?

An internal space that allows organs, distribution of material, and coordination of development.

What’s a Prostosome?

When the mouth is developed before the anu$ such as flatworms, nematodes, arthropods, mollusks, etc.

What’s a Deuterostome?

When the anu$ is developed from the first embryonic opening (blastopore) and the mouth comes later on, which includes echinoderms and chordates.

What is Molting?

When animals with an exoskeleton grow by shedding their exoskeleton.

What is Segmentation?

When the body is divided into segments to function as different locomotion units.

What are Sponges?

They are animals without tissues in the class of Porifera.

What are Cnidarians?

They are carnivores with tissues and radial symmetry that capture prey with tentacles rings in their mouth.

What are Solid Worms?

Worms that have bilateral symmetry.

What are Mollusks?

The only coelomate without a segmented body.

What are the 3 major groups of Mollusks?

Snails, slugs, gastropods, clams, oysters, and octopus.

What are Annelids?

The first segmented animal to evolve.

What are Roundworms?

They are Pseudocoelomates whose molting becomes nematodes.

What are Arthropods?

The most successful animal group that has jointed appendages and does molting for growth and development.

What are Echinoderms?

The first deuterostome that’s a marine vertebrate that has a hard spiny skin or covering.

What are Chordates?

Deuterostomes that have an internal endoskeleton with muscles that attached to an internal rod(notochord).

What is the Water Vascular System?

A fluid- fill system that composed of a central ring canal which five radial canals extend out into the arms.

What is Exoskeleton?

External skeleton that provides structural support and protection for an animal’s body and internal organs.

What is Endoskeleton"?

The internal structure that’s within an animal that provides support, protection, and attachment sites for muscles, typically composed of bone or cartilage.