Sponges and Cnidarians

Food molecules are carried throughout the sponge by

• Choanacytes

• Cnidocytes

• Nematocysts

What are animals that have a backbone called?

• vertebrates

• invertebrates

• eukaryotes

The body symmetry of a cnidarian is

• radial in the medusa stage and bilateral in the polyp stage

• radial in both the medusa and polyp stage

• bilateral in the medusa and polyp stages

Which of the following distinguishes sponges from other invetebrates?

• They reproduce sexually.

• Their cells are not organized into tissue.

• They are not motile in any of their life cycles.

When an animal zygote undergoes a series of divisions to form a hollow ball of cells, it is called a (an)

• anus

• ectoderm

• blastula

In jellyfish, the medusa stage reproduces

• asexually

• by budding

• sexually

Cnidarians have two basic body types, medusa and a (an)

• larva

• tentacle

• polyp

Spicules are

• flexible protein fibers

• hard spike-liked structures in the wall of a sponge

• used for taking in food and water

A blastula is a stage in the development of an embryo that consists of a

• hollow ball of cells

• folded sheet of cells

• solid ball of cells

Sponges reproduce sexually through a process called

• budding

• internal fertilization

• external fertilization