Exam 12: Sponges and Placozoans

Out of all metazoans,members of __________________ have the smallest nuclear genome but the largest mitochondrial genome. The small nuclear genome and large mitochodrial genome of placozoans are characteristics shared with some animal outgroups.

About 95% of the sponges belong to the class __________. Members of the class Demospongiae are the most common sponges.

Flagellated canals of syconoid sponges form by evagination of the body wall and these sponges often develop through a simple vase-like stage.Which of the following is a logical hypothesis based on this evidence?

The demosponges

Cells that move about in the mesohyl,digest particles,and may specialize for other functions are the

Sponge beds have been heavily "fished" for bath sponges and in other cases pollution or an imbalance in organisms has devastated other sponge beds.What is the likely overall consequence of this in the ocean environment?

Which statement about adult sponges is false?

The unique feature of sponge development in members of the class Calcarea is the amphiblastula which

Which is NOT a trait of sponges?

The minute,needle-like structures that act as a skeletal support system in sponges are called _________________. Sponge skeletons are comprised of calcareous or siliceous spicules or spongin.

Which of the following statements about sponges is NOT correct?

The largest impact that the loss of sponges would have on the environment would be

Concerning producing larger organisms without cellular differentiation,

Which one of the following statements regarding the origin of metazoans has the most support?

The simplest of canal systems is found in the

Calcareous or siliceous elements of the sponge body wall provide support. These elements are called

The water outlet in sponges is known as a/an __________________. The osculum is the outlet for water in sponges.

The order in which a drop of ink would pass by the structures in an ascon sponge is

Reproduction in at least some sponges is

A sponge feeds by