Lab 5: Mollusca

Question 1

Evolutionary Radiation

Answer 1

Multiple divergences made from one lineage within a relatively short period of time

Question 2

Adaptive Radiation

Answer 2

Evolutionary Radiation due to adaptation to different environments. (Ecological Diversity)

Question 3

4 Classes of Mollusca

Answer 3

Polyplacophora, Gastropodia, Bivalvia, Cephalopoda

Question 4

Polyplacophora (Example, 2 features)

Answer 4

Chitons, –Broad flat food, shell divided into 8 plates

Question 5

Gastropodia (Examples, 3 features)

Answer 5

Slugs and Snails, –Coiled shell, well defined head, foot for crawling

Question 6

Bivalvia (Examples, 2 features0

Answer 6

Clams, Mussels, Oysters, etc, –Two shells dorsally hinged, filter feeders

Question 7

Cephalopoda(Examples, 5 features)

Answer 7

Squid, Octopi, Cuttlefish etc, –Free swimming, highly cephalized, predator, foot=tentacles, shell absent in most cases

Question 8

Mollusca Coelom

Answer 8

Reduced, replaced mostly by Blood Hemocoel

Question 9

Blood Hemocoel

Answer 9

Blood filled cavity for organs, also serves as hydrostatic skeleton

Question 10

Muscular Foot

Answer 10

Contraction causes locomotion

Question 11

Radula (made of, what it is)

Answer 11

Chitin based ribbon of teeth

Question 12

Buccal Cavity

Answer 12

Mouth

Question 13

Dorsal Visceral Mass

Answer 13

Soft region for organs, but under shell

Question 14

Mantle (made of, functions)

Answer 14

Thin tissue, secretes shell, has beating cilia for current, gas exchange across surface

Question 15

Mantle Cavity

Answer 15

between visceral mass and mantle, open to environment

Question 16

Gills

Answer 16

covered in cilia to create current for water to pass over. Blood in gills contains oxygen binding hemocyanin.

Question 17

Mollusca: Name meaning

Answer 17

“Soft body”

Question 18

Body symmetry

Answer 18

Bilateral

Question 19

Number of Germ Layers

Answer 19

Triploblastic

Question 20

Body Cavity…

Answer 20

Coelomate, Blood Hemocoel

Question 21

Support/Skeletal system

Answer 21

Hydrostatic hemoceol

Question 22

Nervous System/Ceph

Answer 22

Brain, ganglion, and nerve cords

Question 23

Feeding Strategy/Digestive Structures

Answer 23

Radula, complete gut

Question 24

Gas Exchange

Answer 24

Gills or primitive lung, mantle cavity->mantle, diffusion

Question 25

Circulatory System Open or Closed

Answer 25

Both, depends.

Question 26

Lophotrochozoans, or Edycozoans?

Answer 26

Lophotrochozoans