Exam 13: The Smaller Ecdysozoan Phyla

__________ is a condition in which cells,or the nuclei in syncytia,are constant in number for the entire animal,and for a given organ for all members of the species.

A pseudocoelom lacks

The life cycle of Ascaris lumbricoides involves all of the following except one.

The pinworm,Enterobius vermicularis,is the most common nematode parasite in developed countries because the life cycle of this parasite is relatively easy to complete and reinfection and transmission between hosts readily occurs.All of the following,EXCEPT ONE,are attributes of the life cycle that help this parasite thrive.

All of the following have a cuticle that is molted except one.

Necator spp.includes a variety of hookworms.All of the following are characteristics of this genus WITH ONE EXCEPTION.

The pinworm,Enterobius vermicularis,commonly infects humans when

Kinorhynchs are found exclusively in __________ environments.

The most recent ecdysozoan phylum to be described is the phylum

An important function of the cuticle of most ecdysozoans,with the exception of the arthropods,is that

The __________ are some of the most abundant animals on earth.

Nematodes are typically

All of the following statements regarding nematode phylogeny are true except one.

Structures that function in chemoreception and are found at the anterior and posterior ends of nematodes are the

Much of the success of nematodes is due to their

The spiny head of a loriciferan is called the

Ecdysozoan animals

In the osmoregulatory/excretory system of aquatic nematodes,ventral gland cells called __________ are located posterior to the pharynx.

One method of avoiding infection by Trichinella spiralis is to

The nematodes are commonly known as