Phylum Placazoa And Phylum Porifera Study Guide

Question 1

2.) List the characteristics of the Phylum Porifera. A)

Answer 1

A) They are filter feeders.

Question 2

2.) List the characteristics of the Phylum Porifera. B)

Answer 2

B) They lack a digestive tract.

Question 3

2.) List the characteristics of the Phylum Porifera. C)

Answer 3

C) They have asymmetrical body plans.

Question 4

2.) List the characteristics of the Phylum Porifera. D)

Answer 4

D) They lack nerve cells.

Question 5

2.) List the characteristics of the Phylum Porifera. E)

Answer 5

E) Some have radial symmetry.

Question 6

2.) List the characteristics of the Phylum Porifera. F)

Answer 6

F) They have pores called Ostia.

Question 7

2.) List the characteristics of the Phylum Porifera. G)

Answer 7

G) They have a skeleton (not a true skeleton).

Question 8

2.) List the characteristics of the Phylum Porifera. H)

Answer 8

H) One opening at the top called the osculum.

Question 9

3.) Describe how sponges feed.

Answer 9

Collar cells (choanocytes)

• beat the flagella to draw water into the Ostia.
• the microvilli of the collar cells strain food from the water and trap food in the collar.
• cells at the base of the collar will engulf trapped food.

Question 10

4.) What are gemmules?

Answer 10

They are reproductive agents that are associated with survival in freshwater sponges.

Question 11

5.) How do cells of the outer sponge surface obtain their nutrients?

Answer 11

They absorb food that is distributed by the ameboid cells.

Question 12

6.) Name the Kingdom and Phylum for sponges.

Answer 12

The Kingdom is Animalia.

The Phylum is Porifera.

Question 13

7.) How does water enter and exit the sponge?

Answer 13

Water enters through the Ostia.

It exits through the osculum.

Question 14

8.) Name the two skeletal elements of a sponge and write the composition of each of the elements.

Answer 14

The first is spongin which is made of protein.

The second is spicules which is made of calcium carbonate or silica.

Question 15

9.) What does Placazoa mean? What does Porifera mean?

Answer 15

Placazoa means plate animal.

Porifera means pore bearer.

Question 16

10.) When did sponges evolve?

Answer 16

They evolved in the Precambrian period.

Question 17

11.) Know the functions of the following parts.

A) Ameboecyte-

Answer 17

A) Distribute, breakdown and store food as they wander through the sponge.
(They are wandering cells)

Question 18

11.) Know the functions of the following parts.

B) Ostia-

Answer 18

B) Pores that allow water to enter the sponge.

Question 19

11.) Know the functions of the following parts.

C) Osculum-

Answer 19

C) Large opening where water and waste products exit.

Question 20

11.) Know the functions of the following parts.

D) Spongocoel-

Answer 20

D) The hollow opening in the middle of the sponge where wastes are released into and water passes through.

Question 21

11.) Know the functions of the following parts.

E) Choanocytes (collar cells)-

Answer 21

E) Food trapping structures that make up the inner layer of a sponge.

Question 22

11.) Know the functions of the following parts.

F) Spicules-

Answer 22

F) Spicules are crystalline and various shapes that support the body wall.

Question 23

11.) Know the functions of the following parts.

G) Spongin-

Answer 23

G) Protein fibers that are woven to support the body wall.

Question 24

11.) Know the functions of the following parts.

H) Epidermal cells of the ectoderm-

Answer 24

H) Are the outer layer of cells in a sponge.

Question 25

11.) Know the functions of the following parts.

I) Epitheloid cells-

Answer 25

I) Are the outer cells of placazoans.

Question 26

1.) Name an example of a Placazoan.

Answer 26

Trichoplax