Zoology Chapter 11 Exam 2

Front 1

Molluscs are

Back 1

Lophotrochozoans

Front 2

There are roughly this many described species in the phylum Mollusca.

Back 2

100,000

Front 3

The study of similarities and differences in early development of animals is called...

Back 3

Comparitive embryology

Front 4

The entercocoel hypothesis suggests the coelom may have arisen...

Back 4

As outpocketings of the primitive gut

Front 5

The body of molluscs is divided into two main regions calls the...

Back 5

Head-foot and visceral mass

Front 6

The shell of a mollusc is secreted by the...

Back 6

Mantle

Front 7

The inner layer of the mollusc shell is the ________ layer.

Back 7

Nacreous

Front 8

The space between the mantle and foot in a mollusc is called the....

Back 8

Mantle cavity

Front 9

The rasping structure occurring in the mouth of most molluscs is the...

Back 9

Radula

Front 10

Snails, slugs, and limpets belong to the molluscan class...

Back 10

Gastropoda

Front 11

The 180 degree counter clockwise twisting of visceral mass, mantle, and mantle cavity of gastropods is called...

Back 11

Torsion

Front 12

In gastropods, food is trapped in mucus and incorporated into a rotating mucoid mass called the ___________, which extends to the stomach.

Back 12

Protostyle

Front 13

The class of molluscs that contains the most species is the class...

Back 13

Gastropoda

Front 14

The circulatory system of most molluscs is...

Back 14

Open.

Front 15

Among molluscs, extension of body stuctures such as tentacles is accomplished by...

Back 15

A hydraulic skeleton.

Front 16

In some gastropods, a(n) __________ is found on the dorsal, prosterior margin of the foot and when the foot is drawn into the shell, seals the opening.

Back 16

Operculum

Front 17

The primary excretory product of aquatic gastropods is...

Back 17

Ammonia

Front 18

The gastropod larval stage in which torsion occurs is called the....

Back 18

Veliger

Front 19

What is not a member of the class Bivalvia?

Back 19

Chitons

Front 20

The oldest part of the bivalve shell is the...

Back 20

Umbo

Front 21

Muscles responsible for closing the bivalve shell are...

Back 21

Adductors

Front 22

The adaptation of bivalves to sedentary, filter feeding life-styles involved loss of the ___________ and the radula.

Back 22

Head

Front 23

In the bivalves, gas exchange takes place through the...

Back 23

Gills

Front 24

In the bivalves, final digestion occurs...

Back 24

In the digestive gland

Front 25

The modified veliger of some freshwater bivalves is called the...

Back 25

Glochidium

Front 26

Squids, octopuses, cuttlefishes, and nautili belong to the molluscan class...

Back 26

Cephalopoda

Front 27

The most complex molluscs belong to the class...

Back 27

Cephalopoda

Front 28

The only Cephalopods that possess an external shell are the...

Back 28

Nautiloids

Front 29

Unlike other molluscs, the ___________ have a closed circulatory system.

Back 29

Cephalopods

Front 30

Cephalopods typically locate prey by...

Back 30

Sight

Front 31

The similarity of design between the eyes of vertebrates and the eyes of many cephalopods provides an excellent example of...

Back 31

Convergent evolution

Front 32

Pigment cells of cephalopods are called...

Back 32

Chromatophores

Front 33

Sperm packets of cephalpods are called...

Back 33

Spermatophores

Front 34

Tooth shells belong to the molluscan class..

Back 34

Scaphopoda

Front 35

Neopilina represents and molluscan class __________, that was known only from fossils until 1952.

Back 35

Monoplacophora

Front 36

Solenogasters are cylindrical molluscs that lack a shell; they belong to the class...

Back 36

Aplacophora

Front 37

Chitons belong to the molluscan class...

Back 37

Polyplacophora

Front 38

The lack of a ___________ in the molluscan class Aplacophora is thought to be a primitive characteristic.

Back 38

Shell

Front 39

The segmental arrangement of gills, excretory structures, and nervous elements in the __________, make them seem like a "missing link" between molluscs and the annelid-arthropod line.

Back 39

Monoplacophorans

Front 40

The diversity of body forms and life-styles in the phylum Mollusca is an excellent example of...

Back 40

Adaptive radiation

Front 41

The shell-secreting organ of bivalve mollusks is the...

Back 41

Mantle

Front 42

The tentacle of male cephalopods that is modified for spermatophore transfer is the...

Back 42

Hectocotylus

Front 43

Molluscs possess this type of skeleton.

Back 43

Hydraulic