Molluscs

Question 1

What is the human importance of molluscs

Answer 1

Food (calamari, mussels, scallops, clams)

Pearl + shells

Bio-indicators

Biotech (bullet proof veste)

Question 2

What are the two important features that make a mollusc a mollusc?

Answer 2

Visceral mass

Head foot

Question 3

What is the head foot used for in molluscs

Answer 3

Sensory snd locomotion

Question 4

Where is the radula found in molluscs?

Answer 4

Head foot

Question 5

What is the radula in molluscs?

Answer 5

Chitinous ribbon teeth

Held together by odontophore cartilage

Ribbon teeth move over cartilage
Odontophore can move in and out

Question 6

What is highly modified among the different classes of molluscs, found on the ventral side and used primarily for locomotion?

Answer 6

Foot

Question 7

What is the visceral mass of molluscs?

Answer 7

Mantle + mantle cavity

Question 8

The skin that wraps around the body and protects the soft parts of the mollusc, extending from the visceral mass, is called what?

Answer 8

Mantle

Question 9

What part of the visceral mass makes the shell

Answer 9

Mantle

Question 10

What are the three layers of the mantle and shell

P-P-N

Answer 10

1. Peristracum
2. Promatic
3. Nacre

Question 11

What layer of the shell is the outer organic proteinaceous layer?

(Skin of shell)

Answer 11

Peristracum

Question 12

What layer is the thickest with lots of calcium carbonate stacks that are in a proteinaceous matrix?

(Some of the strongest material on earth)

Answer 12

Prismatic

Question 13

What is the nacre layer of the shell?

Answer 13

Shiny + smooth inner layer
Continually laid down
Where pearls are made

Question 14

What is nacre made out of?

Answer 14

Calcium carbonate + protein sheets

Question 15

How is a pearl made?

Answer 15

Debris gets btw shell + mantle sand)

Nacre lays down overtop debris

Makes pearl

Question 16

Molluscs
Symmetry?
Body cavity?

Answer 16

Bilateral

Coelomates

Question 17

Can molluscs be asexual

Answer 17

No

Male, female or hermaphroditism

Question 18

What kind or larvae do molluscs have?

Answer 18

Aquatic larvae or gastropods = TROCHOPHORE LARVAE

some have veliger larvae

Some direct development (cephalopods + snails)

Question 19

What kind of larvae to cephalopds and snails have?

Answer 19

Direct development

Question 20

What are the 8 classes of molluscs?

Answer 20

Aplacophorans (combo of 2 classes)
Bivalvia
Cephalopods
Gastropods
Monoplacophora
Polyplacophora

Question 21

The aplacophorans are a combination of 2 classes of mollusc… what are they

Answer 21

Causofoveata + solengastres

Question 22

What class of molluscs is worm like, NO SHELL + NO FOOT and is a marine burrower with calcareous scales/spicules?

Answer 22

Aplacophorans

Question 23

What are some key characteristics of class monoplacophora?

Answer 23

One plate
Rounds shell
Big foot
Plates repeat

Question 24

What class are many repeating internal and external strucutres (gills + nerves) and is kinda like the molluscs armadillo because of its many plates (8 movable plates)

Answer 24

The polyplacophora

Question 25

What class are the chitons under in molluscs?

Answer 25

Polyplacophora

Question 26

What is indicative of class scaphopoda?

Answer 26

Tusk shells / tooth shells Tubular Modified with tentacles - sticky ends = captacula!!! NL HEART + NO GILLS

Question 27

What class has no heart and no gills (molluscs)?

Answer 27

scaphopoda

Question 28

What group of the gastropods is mostly marin snails like periwinkles, limpets and conchs? Prosssssssss...

Answer 28

Prosobranchia | Pros bra

Question 29

Opisthobranchia are what type of gastropods..

Answer 29

Shell less, marine Nudibranchs and sea slugs

Question 30

Do nudibranchs and sea slugs have gills and shell?

Answer 30

No, because they are part of opisthobranchia group of gastropods

Question 31

What group of gastropods have cerrata (dorsal extensions along mantle edge)?

Answer 31

Opisthobranchia

Question 32

Most land and fresh water snails belong to what group of gastropods or phylum mollusc? Pull mon

Answer 32

Pulmonata

Question 33

Whats the difference btw torsion and coiling in gastropods?

Answer 33

Tosrsion = 180 deg rotation of mantle (anus and gills) Coiling = whorling or shell Head near butt

Question 34

The cone snail is an example of a unique feeding method of the gastropods... what feature is usually highly varied to make gastropod feeding so unique

Answer 34

Radula

Question 35

How do gastropod hermaphrodites who are marine differ from hermaphrodites who are on land?

Answer 35

Marine = veliger larva Land = protective egg cases

Question 36

Gatropod reproduction - explain simultaneous hermaphrodites

Answer 36

Mating rituals - build pressure for LOVE DART copulatory organs in head Love dart = eversible penis + vagina They stab each other in the head

Question 37

Are gastropods monoecious dioecious or hermaphrodites?

Answer 37

All three

Question 38

What has no radual, no head, just two valves and a laterally compressed shell

Answer 38

Class bivalvia

Question 39

Sedentary suspension feeders of class bivalvia have gills covered in... and use what to help direct water flow

Answer 39

Ciliated mucus covers gills Siphon for water flow

Question 40

What features to burrowing forms of bivalves (like clams) have to keep water flow even when burrowed

Answer 40

Large muscular foot on anterior/ventral Siphon on posterior Keeps water flow even

Question 41

What is the oldest part lf the bivalves shell and what does this part do?

Answer 41

Umbo Where hinge is - where it grows from Dorsal side

Question 42

What muscles open and closes the shell in class bivalvia?

Answer 42

Abductor muscles

Question 43

What does the term ctenidia mean in bivalves?

Answer 43

Gills

Question 44

Where are the gills of bivalves found? What are they covered in?

Answer 44

Dorsal side Covered in mantle sheath

Question 45

How are gills used for feeding and respiration in bivalves?

Answer 45

Particles come in posterior’ Go along cilia tracts of gills Sand rejected out ventral side Food goes to anterior end where palps turn it into bolus

Question 46

How to clams move differently than scallops? what about sessile bivalves like mussels and oysters?

Answer 46

Clams = burrow Scallops = clap and swim with abductor muscles Mussels = byssal threads Oysters = cement to substrate

Question 47

Nautiloids, cuttlefish, squids, octopuses belong to what class of mollusc?

Answer 47

Cephalopod

Question 48

What type of cephalopod has a large shell, lives in outer most shell layer but regulates the gas pressure with its SIPHUNCLE?

Answer 48

Nautiloids

Question 49

What kind of shell do cuttle fish have? What about squids? Ocotpuses?

Answer 49

Cuttle fish = internal shell enclosed by mantle Squids = pen (dorsal) enclosed by mantle Octopuses = no shell

Question 50

Cephalopods - how do they move?

Answer 50

Jet propulsion - muscle walled mantle contracts - water shoot out siphon - animal shoots backwards

Question 51

What is the basic body plan of cephalopds

Answer 51

1 pair of gills 8 arms - suckers / hooks Closed circulatory system Nervous system + eyes

Question 52

How to the chromatophore cells help cephalopds camouflage?

Answer 52

Change colour by getting bigger or smaller in diameter

Question 53

What do the ink sacs of cephalopods contain? Where are the ink sacs found?

Answer 53

Melanin + sometimes mucus Rectum

Question 54

What class of mollusc is exclusively dioecious?

Answer 54

Cephalopods

Question 55

How do cephalopds reproduce?

Answer 55

Sperm passed in packets to females Fertlized eggs leave females, laid on rocks She protects them

Question 56

Do cephalopds have a larval stage? If yes, what type of larva?

Answer 56

No larvae Direct development

Question 57

What is meant by cephalopds are semelparous?

Answer 57

Die after mating

Question 58

What are the 5 key body transitions of molluscs?

Answer 58

``` O - organ S - bilateral BC - eucoelomate D - triploblast/protostomes/lophotrochozoa Segmentation - no ```