Chapter 4- Poriferans and Placozoans

Question 1

The central cavity within a sponge where water flows.

Answer 1

Spongocoel

Question 2

Specialized cells in sponges that have flagella and line the spongocoel, creating water currents and filtering food.

Answer 2

Choanocytes

Question 3

Another name for choanocytes, highlighting their structure that resembles a collar around the flagellum.

Answer 3

Collar cells

Question 4

The gelatinous layer found between the outer layer (pinacoderm) and the inner layer (choanocyte layer) of sponges.

Answer 4

Mesohyl

Question 5

Amoeboid cells in sponges that can differentiate into various cell types and are involved in digestion, regeneration, and producing gametes.

Answer 5

Archaeocytes

Question 6

Structural elements made of silica or calcium carbonate, providing support and shape to sponges.

Answer 6

Spicules

Question 7

A type of flexible, fibrous protein that forms part of the skeleton in some sponges, providing structural support.

Answer 7

Spongin

Question 8

Cells within sponges that secrete spicules.

Answer 8

Sclerocytes

Question 9

Cells that produce spongin fibers.

Answer 9

Spongocytes

Question 10

Dormant structures produced by freshwater sponges that can survive harsh environmental conditions.

Answer 10

Gemmules

Question 11

The requirement of a period of cold or certain environmental conditions to promote the hatching of gemmules.

Answer 11

Vernalization

Question 12

Flattened contractile cells that form the outer layer of sponge tissue, contributing to the overall shape of the sponge.

Answer 12

Pinacocytes

Question 13

The outermost layer of cells in sponges, composed mainly of pinacocytes.

Answer 13

Pinacoderm

Question 14

A layer of extracellular matrix that supports epithelial cells in many organisms, though sponges lack a true basal lamina.

Answer 14

Basal lamina

Question 15

Small openings in the sponge body through which water enters.

Answer 15

Ostia

Question 16

Larger openings through which water exits the spongocoel.

Answer 16

Oscula

Question 17

A class within the phylum Porifera characterized by sponges with calcium carbonate spicules.

Answer 17

Class Calcarea

Question 18

Referring to an organism that has both male and female reproductive organs and can produce both sperm and eggs.

Answer 18

Hermaphroditic

Question 19

A type of sponge embryo that develops into a hollow blastula stage.

Answer 19

Coeloblastula

Question 20

A free-swimming larval stage in some calcareous sponges, characterized by flagellation at one end.

Answer 20

Amphiblastula

Question 21

An embryo that becomes solid after initially being hollow.

Answer 21

Stereoblastula

Question 22

A type of larval stage in sponges that is characterized by having numerous flagellated cells.

Answer 22

Parenchymella

Question 23

Another term for parenchymella, emphasizing its developmental stage.

Answer 23

Parenchymula