4: Mollusca part 2

Question 1

• “stomach foot”
• largest class of mollusks
• only class w terrestrial species
• either shell-bearing or have reduced shell

Answer 1

gastropoda

Question 2

• part that’s always univalve when present
• gets larger and spirals around central axis

Answer 2

shell

Question 3

contains smallest and oldest whorl in shell

Answer 3

apex

Question 4

opening is often colored w an operculum in shell

Answer 4

aperture

Question 5

• rotation of shell, mantle, and visceral organs in gastropod development
• allows head to be withdrawn into mantle cavity
• leads to anus and mantle cavity opening above head

Answer 5

torsion

Question 6

refers to problem of waste products from anus and nephridia potentially contaminating organs in mantle cavity

Answer 6

fouling

Question 7

spiral winding of shell and visceral mass

Answer 7

coiling

Question 8

venom administered by modified radula in venomous cone snails; lethal to humans in several species

Answer 8

conotoxin

Question 9

gastropoda subclass:
- largest group; most marine snails, some terrestrial/freshwater
- one pair of tentacles

Answer 9

prosobranchia

Question 10

gastropoda subclass:
- sea slugs, sea hares, sea butterflies
- mostly marine and shallow water
- 2 pairs of tentacles

Answer 10

opisthobranchia

Question 11

gastropoda subclass:
- land/most freshwater snails/slugs w a few brackish and marine species
- no ctenidia; mantle cavity has a lung

Answer 11

pulmonata

Question 12

mollusca class:
- “two valves”
- mostly marine w some living in freshwater/brackish environments
- majority sedentary filter-feeders
- no head, radula, minimal cephalization

Answer 12

bivalvia

Question 13

holds 2 valves together

Answer 13

hinge ligament

Question 14

oldest part of shell

Answer 14

umbo

Question 15

byproduct of a response to irritation caused by a foreign object; mantle secretes many layers of nacre around it

Answer 15

pearls

Question 16

highly modified for filter feeding; where gas exchange occurs along w the mantle

Answer 16

ctenidia

Question 17

brings water and food particles into the mantle cavity

Answer 17

respiratory currents

Question 18

have bacteria that produce cellulase to allow them to digest wood

Answer 18

shipworms

Question 19

get nutrition from photosynthetic products of dinoflagellates

Answer 19

giant clams

Question 20

mollusca class:
- “head foot”
- all marine active predators
- octopus, squid, cuttlefish, nautilus

Answer 20

cephalopoda

Question 21

only surviving cephalopod w an external shell

Answer 21

nautilus

Question 22

where cephalopods move by expelling water from the mantle cavity

Answer 22

siphon

Question 23

cells that facilitates color changing in cephalopods

Answer 23

chromatophores

Question 24

cephalopod subclass: genus nautilus is the only surviving member, 2 pairs of gills

Answer 24

nautiloidea

Question 25

cephalopod subclass: ammonites, all extinct after creataceous

Answer 25

ammonoidea

Question 26

cephalopod subclass: all other living cephalopods, 1 pair of gills

Answer 26

coleoidea