Question 1

The outer thin,flat,epithelial-like cells that cover the outside and some inside surfaces of sponges,are

Accepted Answer

A)  amoebocytes. 
B)  pinacocytes. 
C)  choanocytes. 
D)  spicules. 
E)  spongin.
Pinacocytes line the outer surface of the body wall of sponges. They may ingest food by phagocytosis and many are contractile to help regulate water flow. 
A)  amoebocytes. 
B)  pinacocytes. 
C)  choanocytes. 
D)  spicules. 
E)  spongin.
Pinacocytes line the outer surface of the body wall of sponges. They may ingest food by phagocytosis and many are contractile to help regulate water flow.

Question 2

The tough protein fibers sometimes found in sponge skeletons are of a substance called _____________.
Sponge skeletons are comprised of calcareous or siliceous spicules or spongin.

Accepted Answer

The answer of The tough protein fibers sometimes found in...

Question 3

Deep-sea sponges with six-rayed siliceous spicules and a trabecular reticulum belong to the ______________.
Hexactinellids are sponges with six-rayed spicules and a trabecular reticulum.

Accepted Answer

Hexactinel

Question 4

Explain the concept of monophyly as it applies to the animals. How do the relationships of placozoans and poriferans,as explained in this chapter,contribute to our understanding of the base of the animal tree shown on the inside cover of the book?

Accepted Answer

Monophyly refers to a group of organisms

Question 5

Specialized archaeocytes that secrete spicules are

Accepted Answer

A)  collencytes. 
B)  sclerocytes. 
C)  choanocytes. 
D)  spongocytes. 
E)  lophocytes.
Archaeocytes may be specialized as sclerocytes, which secrete spicules. 
A)  collencytes. 
B)  sclerocytes. 
C)  choanocytes. 
D)  spongocytes. 
E)  lophocytes.
Archaeocytes may be specialized as sclerocytes, which secrete spicules.

Question 6

Why are bath sponges so soft?

Accepted Answer

A)  Silica is washed away and the calcium carbonate remains 
B)  Spongin spicules are washed away and the silky silica remains 
C)  The choanocytes and amoebocytes are softer 
D)  Bath sponge support is provided primarily by spongin proteins 
E)  All of the choices are correct
Spongin is a soft protein present in the body wall of bath sponges. Bath sponges lack calcareous or siliceous spicules. 
A)  Silica is washed away and the calcium carbonate remains 
B)  Spongin spicules are washed away and the silky silica remains 
C)  The choanocytes and amoebocytes are softer 
D)  Bath sponge support is provided primarily by spongin proteins 
E)  All of the choices are correct
Spongin is a soft protein present in the body wall of bath sponges. Bath sponges lack calcareous or siliceous spicules.

Question 7

Specialized archaeocytes that secrete large quantities of collagen are

Accepted Answer

A)  collencytes. 
B)  sclerocytes. 
C)  choanocytes. 
D)  spongocytes. 
E)  lophocytes.
Lophocytes are archeocytes specialized for secreting collagen. 
A)  collencytes. 
B)  sclerocytes. 
C)  choanocytes. 
D)  spongocytes. 
E)  lophocytes.
Lophocytes are archeocytes specialized for secreting collagen.

Question 8

The modified cells of sponges that form circular bands and provide just a little constriction to control water flow are

Accepted Answer

A)  amoebocytes. 
B)  choanocytes. 
C)  spicules. 
D)  myocytes.
Myocytes are modified pinacocytes and constrict to regulate water flow. 
A)  amoebocytes. 
B)  choanocytes. 
C)  spicules. 
D)  myocytes.
Myocytes are modified pinacocytes and constrict to regulate water flow.

Question 9

In glass sponges,archaeocytes fuse their pseudopodia to form a

Accepted Answer

A)  bud. 
B)  spongin network. 
C)  micropyle. 
D)  leuconoid framework. 
E)  trabecular reticulum.
Hexactinellid sponges possess a unique syncytial body wall. All cells fuse into a single, multinucleate syncytum called the trabecular reticulum. 
A)  bud. 
B)  spongin network. 
C)  micropyle. 
D)  leuconoid framework. 
E)  trabecular reticulum.
Hexactinellid sponges possess a unique syncytial body wall. All cells fuse into a single, multinucleate syncytum called the trabecular reticulum.

Question 10

Thin,epithelial-type cells covering the outer surface of sponges are the ________________.
Pinacocytes make up the pinacoderm,the outer cellular layer of a sponge.

Accepted Answer

The answer of Thin,epithelial-type cells covering the outer surface of...

Question 11

Placozoans feed by

Accepted Answer

A)  sharing food produced by symbiotic algae in their diffuse tissues 
B)  Gliding over their food, secreting enzymes, and absorbing products 
C)  Filtering food that moves through them in tiny pores 
D)  Taking food in through a ventral tube, digesting it, and expelling wastes back out the tube 
E)  Taking food in through a central tube, digesting it, and moving wastes out the anus
Placozoans lack organs, including digestive organs. They secrete digestive enzymes as they glide over their food. Products of digestion are absorbed by the ventral epithelium. 
A)  sharing food produced by symbiotic algae in their diffuse tissues 
B)  Gliding over their food, secreting enzymes, and absorbing products 
C)  Filtering food that moves through them in tiny pores 
D)  Taking food in through a ventral tube, digesting it, and expelling wastes back out the tube 
E)  Taking food in through a central tube, digesting it, and moving wastes out the anus
Placozoans lack organs, including digestive organs. They secrete digestive enzymes as they glide over their food. Products of digestion are absorbed by the ventral epithelium.

Question 12

New evidence suggests that the calcarea belong to a clade separate from other sponges.Discuss the evidence upon which this idea is based.

Accepted Answer

The new evidence suggesting that the cal

Question 13

Cells responsible for water flow and capture of some particles are the

Accepted Answer

A)  myocytes. 
B)  archaeocytes. 
C)  choanocytes. 
D)  pinacocytes. 
E)  lophocytes.
Choanocytes are responsible for water flow and capture of some food particles. 
A)  myocytes. 
B)  archaeocytes. 
C)  choanocytes. 
D)  pinacocytes. 
E)  lophocytes.
Choanocytes are responsible for water flow and capture of some food particles.

Exam 12: Sponges and Placozoans

The outer thin,flat,epithelial-like cells that cover the outside and some inside surfaces of sponges,are

The tough protein fibers sometimes found in sponge skeletons are of a substance called _____________. Sponge skeletons are comprised of calcareous or siliceous spicules or spongin.

Deep-sea sponges with six-rayed siliceous spicules and a trabecular reticulum belong to the ______________. Hexactinellids are sponges with six-rayed spicules and a trabecular reticulum.

Explain the concept of monophyly as it applies to the animals. How do the relationships of placozoans and poriferans,as explained in this chapter,contribute to our understanding of the base of the animal tree shown on the inside cover of the book?

Specialized archaeocytes that secrete spicules are

Why are bath sponges so soft?

Specialized archaeocytes that secrete large quantities of collagen are

The modified cells of sponges that form circular bands and provide just a little constriction to control water flow are

In glass sponges,archaeocytes fuse their pseudopodia to form a

Thin,epithelial-type cells covering the outer surface of sponges are the ________________. Pinacocytes make up the pinacoderm,the outer cellular layer of a sponge.

Placozoans feed by

New evidence suggests that the calcarea belong to a clade separate from other sponges.Discuss the evidence upon which this idea is based.

Cells responsible for water flow and capture of some particles are the

Life: Biological Principles and the Science of Zoology

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