Question 1

By lining up all the crayfish appendages,you would find that they possess

Accepted Answer

A)  two pairs of abdominal swimmerets that are different in males and females. 
B)  a telson tail. 
C)  two large pincers. 
D)  two branches on all appendages. 
E)  All of the choices listed are crayfish appendages.

Question 2

Crustacea are biramous,meaning they possess

Accepted Answer

A)  a telson tail. 
B)  two large pincers. 
C)  two pair of antennae. 
D)  jointed appendages having two branches. 
E)  a body divided into two regions, the cephalothorax and abdomen.

Question 3

The major body space in arthropods is called the ______________.

Accepted Answer

The answer of The major body space in arthropods is...

Question 4

How do crustacea differ from other arthropod groups?

Accepted Answer

A)  They possess a telson tail 
B)  Only crustaceans have two pairs of antennae 
C)  Only crustaceans have chitinous exoskeletons 
D)  Only Crustacea possess a two-part body plan of cephalothorax and abdomen 
E)  A hemocoel is only found in Crustacea

Question 5

Which is a correct association of pigment and function in an arthropod compound eye?

Accepted Answer

A)  Strong light-distal retinal pigment disappears 
B)  Strong light-each ommatidium is shielded from the others and sees only a limited area 
C)  Strong light-distal and proximal pigments separate 
D)  Dim light-each ommatidium is shielded from the others and sees only a limited area 
E)  Dim light-distal and proximal pigments fuse

Question 6

A characteristic unique to Crustacea is the possession of two pairs of _______________.

Accepted Answer

The answer of A characteristic unique to Crustacea is the...

Question 7

The respiratory apparatus of a crayfish is

Accepted Answer

A)  a set of gills under the carapace. 
B)  book lungs inside the carapace. 
C)  a set of gills along the underside of the tail. 
D)  tracheal tubes throughout the body. 
E)  a cluster of alveoli under the tail.

Question 8

A subclass of crustaceans that are of extreme ecological importance,often dominating the primary consumer level in aquatic communities,is the _______________.

Accepted Answer

The answer of A subclass of crustaceans that are of...

Question 9

Both clams and crabs are referred to in common terminology as "shellfish." However,zoologists do not consider them to be closely related.Provide a contrasting list of the differences between the crustacean decapods and the molluscan bivalves.

Accepted Answer

The answer of Both clams and crabs are referred to...

Question 10

The group of Crustacea with the most ancestral features,including a long trunk with fairly uniform appendages,is the

Accepted Answer

A)  maxillopoda. 
B)  cirripedia. 
C)  isopoda. 
D)  decapoda. 
E)  remipedia.

Question 11

The segments of crustaceans are covered with a dorsal plate or _____________ and a ventral plate or ______________.

Accepted Answer

A)  epiproct, underproct 
B)  flexor, extensor 
C)  endopod, exopod 
D)  endite, exite 
E)  tergum, sternum

Question 12

Since the hemolymph of crustaceans leaves the heart by arteries,why is it considered an open rather than a closed system?

Accepted Answer

A)  The hemolymph lacks any respiratory pigments. 
B)  The hemolymph flows through the hemocoel and returns via venous sinuses rather than enclosed veins. 
C)  The heart does not pump hemolymph but it moves by ciliary action instead. 
D)  The arteries "dead end" and the hemolymph must backflow through the arteries. 
E)  The hemolymph lacks any respiratory function.

Question 13

Describe the sequence of events that occur during molting and ecdysis in a crayfish and explain why a "softcraw" is vulnerable until it has hardened its shell.

Accepted Answer

The answer of Describe the sequence of events that occur...

Question 14

Crustaceans are often referred to as the "insects of the sea." This is partially because crustaceans are so abundant in the sea,as insects are on land,and because insects never successfully invaded the marine environment.Discuss why crustaceans 1)are so abundant in the ocean,and 2)why they did not radiate extensively into terrestrial environments.

Accepted Answer

The answer of Crustaceans are often referred to as the...

Question 15

Crustaceans and molluscs of course do have a common ancestor at some point.Draw a reasonable phylogeny that includes the molluscs,annelids and arthropods including the crustacea,and describe the distinguishing features on each branch.There are several legitimate phylogenies.

Accepted Answer

The answer of Crustaceans and molluscs of course do have...

Question 16

The first pair of walking legs in a crayfish,lobster,crab,and their relatives,that is enlarged with a terminal claw is the

Accepted Answer

A)  protopodite. 
B)  statocyst. 
C)  cheliped. 
D)  pedipalp. 
E)  exopodite.

Question 17

Based on a count of individual organisms,a species in the copepod genus Calanus is likely the most abundant animal in the world.What features do copepods possess and what environmental factors contribute to this record status?

Accepted Answer

The answer of Based on a count of individual organisms,a...

Question 18

Discuss the evolutionary significance of the serial homology of crustacean appendages.

Accepted Answer

The answer of Discuss the evolutionary significance of the serial...

Question 19

Androgenic glands in the amphipod function to

Accepted Answer

A)  regulate ion balance. 
B)  stimulate expression of male characteristics. 
C)  control pigmentation for camouflage. 
D)  secrete digestive fluids. 
E)  control ecdysis.

Question 20

The green glands form an effective "flood control" device in the freshwater crayfish by

Accepted Answer

A)  forming a dilute, low-salt urine to unload the water that diffuses into the crayfish body. 
B)  forming a high-salt urine to unload the high salt built up in the crayfish body. 
C)  keeping the urine isosmotic to the blood. 
D)  keeping the interior hemocoel dry. 
E)  producing extra sodium and chloride ions to maintain the ionic balance.

Exam 20: Crustaceans