Review Questions

Mesohyl contains:

1. a polysaccharide gel and dead cells.
2. a collagen-like gel and suspended cells for various functions.
3. spicules composed of silica or calcium carbonate.
4. multiple pores.

The large central opening in the parazoan body is called the:

1. gemmule.
2. spicule.
3. ostia.
4. osculum.

Most sponge body plans are slight variations on a simple tube-within-a-tube design. Which of the following is a key limitation of sponge body plans?

1. Sponges lack the specialized cell types needed to produce more complex body plans.
2. The reliance on osmosis/diffusion requires a design that maximizes the surface area to volume ratio of the sponge.
3. Choanocytes must be protected from the hostile exterior environment.
4. Spongin cannot support heavy bodies.

Cnidocytes are found in _____.

1. phylum Porifera
2. phylum Nemertea
3. phylum Nematoda
4. phylum Cnidaria

Cubozoans are ________.

1. polyps
2. medusoids
3. polymorphs
4. sponges

While collecting specimens, a marine biologist finds a sessile Cnidarian. The medusas that bud from it swim by contracting a ring of muscle in their bells. To which class does this specimen belong?

1. Class Hydrozoa
2. Class Cubozoa
3. Class Scyphozoa
4. Class Anthozoa

Which group of flatworms are primarily ectoparasites of fish?

1. monogeneans
2. trematodes
3. cestodes
4. turbellarians

The rhynchocoel is a ________.

1. circulatory system
2. fluid-filled cavity
3. primitive excretory system
4. proboscis

Annelids have (a):

1. pseudocoelom.
2. true coelom.
3. no coelom.
4. none of the above

A mantle and mantle cavity are present in:

1. phylum Echinodermata.
2. phylum Adversoidea.
3. phylum Mollusca.
4. phylum Nemertea.

How does segmentation enhance annelid locomotion?

1. Segmentation creates repeating body structures so the entire organism functions in synchrony.
2. Segmentation allows specialization of different body regions.
3. Neural segmentation allows annelids to localize sensations.
4. Muscle contractions can be localized to specific regions of the body to coordinate movement.

The embryonic development in nematodes can have up to __________ larval stages.

1. one
2. two
3. three
4. four

The nematode cuticle contains _____.

1. glucose
2. skin cells
3. chitin
4. nerve cells

Crustaceans are _____.

1. ecdysozoans
2. nematodes
3. arachnids
4. parazoans

Flies are_______.

1. chelicerates
2. hexapods
3. arachnids
4. crustaceans

Which of the following is not a key advantage provided by the exoskeleton of terrestrial arthropods?

1. Prevents dessication
2. Protects internal tissue
3. Provides mechanical support
4. Grows with the arthropod throughout its life

Echinoderms have _____.

1. triangular symmetry
2. radial symmetry
3. hexagonal symmetry
4. pentaradial symmetry

The circulatory fluid in echinoderms is _____.

1. blood
2. mesohyl
3. water
4. saline

Which of the following features does not distinguish humans as a member of phylum Chordata?

1. Human embryos undergo indeterminate cleavage.
2. A spinal cord runs along an adult human’s dorsal side.
3. Human embryos exhibit pharyngeal arches and gill slits.
4. The human coccyx forms from an embryonic tail.

The sister taxon of the Chordata is the _____.

1. Mollusca
2. Arthropoda
3. Ambulacraria
4. Rotifera