Why do birds have salt glands? 

Organisms that are in group hirudinea are known as leeches. 

What is the function of the pyloric stomach in starfish? 

What is the function of green glands? 

Echinoderm skeletons are made of? 

The syrinx is a specialized region of the airways that serve as a voicebox in birds.

The plates that make up the echinoderm skeleton are referred to as spiny plates.

Organisms in phylum Porifera are . Oranisms that fall into phylum Cnidaria possess . 

Why are the large surface to volume ratios of cnidarians so important? 

Parasitic nematodes exhibit a different type of excretory system compared with aquatic nematodes.