Ch.12 Review Textbook Questions

Question 1

The term “metazoan” is synonymous with “animal”. Are there any single-celled animals?

Answer 1

No,

Question 2

How are single celled eukaryotes classified?

Answer 2

protozoans

Question 3

Contrast colonial and multicellular body plan

Answer 3

Colonial body plan: Colonies made up of single-celled organisms that can’t survive on their own if separated

Multicellular body plan: Many cells work in conjunction with each other and can’t survive on their own

Question 4

Describe the asconoid body plan?

Answer 4

Small tube shaped, simple
H2O goes thru the dermal ostia into the flagellated spongocoel lined w/ choanocytes and exists thru the osculum

Question 5

Describe the synconoid body plan?

Answer 5

Larger, thicker body wall water enters thru the dermal ostia into the incurrent canals thru prosophyles to radial canals lined w/ choanocytes passing thru apopyles into spongocoel lined w/ epithelial cells and exists thru the osculum

Question 6

Describe the leuconoid body plan?

Answer 6

large w/ more oscula, cluster of flagellated chambers filled from incurrent canals, the excurrent canals deliver water to one or more oscula

Question 7

What sponge body type appears most efficient and makes possible the largest body size

Answer 7

leuconoid

Question 8

How does the design of sponges influence the speed of water movement to maximize food capture and minimize ingestion of used water

Answer 8

The porous body structure, coordinated action of specialized cells like choanocytes, and the unidirectional flow of water all contribute to maximizing food capture while minimizing the ingestion of used water.

Question 9

Describe the skeletons of each class of sponges

Answer 9

Homoscleromorpha - absecent skeleton calcareous spicules

Calcispongiae- calcium carbonate spicules, small tube shape

Demospongiae- silica spicules, not w/ 6 rays, spongin

Hexactinellida- glass sponge made of silica, spicules w/ six rays, radial symmetry

Question 10

What is a gemmule ?

Answer 10

an asexual reproductive structure produced by some freshwater sponges

Question 11

Describe the body plan of Placozoa

Answer 11

plate-like, no symmetry muscular or nervous system glide over food, secrete digestive enzymes and absorb the products

Question 12

What features make placozoans interesting from a phylogenetic perspective?

Answer 12

the life cycle is not completely known divide asexually by budding and produces eggs