Which of the following types of skeletal material is not found in at least some sponges?
select one:
a. spongin
b. muscle
c. calcium carbonate
d. spicules
e. silica

b. muscle

Explanation:

The Sponges usually known as Porifera (pore bearers) are aquatic filter feeders. The sponges consist of structural materials (spongin, spicules) which are usually made of calcium carbonate and/or silica. These structures forms their skeletal materials giving their body a thin sheet of cells over a frame (skeleton). As invetebrate and at the unicellular level of organization, Sponges lack muscle.

Muscle is not found in some sponges I've spent the last hour doing reserch on sponges for school and haven't seen many with muscle.

six grader is what i am ssorry

earthquakes in florida are rare because the state is not located near any tectonic plates. in fact, florida is tied for first place as having the fewest earthquakes of any state. much of florida is limestone and seafloor materials that is not conducive to earthquakes.

explanation: