Phylum mollusca

Question 1

• Soft body
• Occupy a great range of habitat
• a large phylum of invertebrate animals (animals without a backbone)

Answer 1

Phylum mollusca

Question 2

The two mollusk body plan

Answer 2

• Head-foot portion
• Visceral Mass

Question 3

• depends primarily on muscular action for its action
• more active area, containing: Feeding, Locomotor organs, cephalic sensory

Answer 3

Head-foot portion

Question 4

• portion containing digestive circulatory, respiratory, and reproductive organs
• depends primarily on ciliary tracts for its functioning

Answer 4

Visceral Mass

Question 5

• Have valves or plates for protection
• Have gills lining the sides of their body
• Dorsoventrally flat with foot used as a “suction cup”
• Lives on rocky areas on the beach
• Undergoes metamorphosis
• Free-swimming larval stage * More sessile adult stage

Answer 5

Class polyplacophora

Question 6

example of class polyplacophora

Answer 6

Chilton

Question 7

• Have tusk-like shells
• Foot specialized for digging in the substrate
  (either sand or mud)
• Found in the subtidal zone (underwater)
• Have two openings: bigger opening is where the foot and tentacles emerge; smaller one used to relieve pressure
  Tentacles used as feelers and for grabbing food; food particles will be shred by the radula found inside the shell
• Undergoes metamorphosis
• Free-swimming larval stage * More sessile adult stage

Answer 7

Class scaphopoda

Question 8

• Pronounced muscular foot
• Siphon used for respiration (sucking in water) or for buoyancy maintenance (sucking air or releasing air to stay afloat or to sink)
• Have radula (rows of teeth)
• Has an operculum that closes the
  aperture/opening of the shell
• For protection against environmental conditions (e.g. lack of water)
• For protection against predators

Answer 8

Class gastropod

Question 9

• Have two shells connected on a hinge
• Have foot specialized for digging or pushing the substrate
• Siphons used to suck water and food particles in
• Have nacre: a shiny substance used to coat irritants and infected internal parts; creates pearl
• Eyes are usually rudimentary; only detects light and dark
• Undergoes metamorphosis
• Some have free-swimming larval stage; others have larvae that latch onto fish gills to facilitate their spread
• More sessile adult stage

Answer 9

Class bivalvia

Question 10

• Most living members do not have external shells (except for nautilus)
• Shells are reduced as an internal, plastic-like structure
• Have well-developed eyes
• Have well-developed nervous systems
• Have beaks that are used to crush the shells of their prey
• Have pronounced and specialized tentacles
• Do not undergo metamorphosis; instead, they undergo direct development (baby to adult; no larval and adult stage)

Answer 10

Class cephalophoda

Question 11

What are the classes that have eyes that are rudimentary

Answer 11

• Class Gastropoda
• Class Bivalvia

Question 12

What are classes that undergoes metamorphosis?

Answer 12

All of them except class cephalophoda

Question 13

What is a radula

Answer 13

Rows of teeth

Question 14

Closes the aperture / opening of the shell
- protection against environmental conditions
- protection against predators

Answer 14

Operculum

Question 15

why does class cephalophoda dont undergo metamorphosis?

Answer 15

because they undergo direct development instead

Question 16

Clam is an example of?

Answer 16

Class bivalvia

Question 17

Nauticus, Squid

Answer 17

Class Cephalophoda

Question 18

Whelk

Answer 18

Class Gastropoda

Question 19

Chilton

Answer 19

Class Polyplacophora

Question 20

a shiny substance used to coat irritants and infected internal parts; creates pearl

Answer 20

Nacre