LESSON 9: PHYLUM MOLLUSCA

Question 1

widely characterized as soft-bodied invertebrates enclosed in a calcium carbonate shell; there are over 75,000 described species, making them the second most diverse phylum of animals

Answer 1

Phylum Mollusca

Question 2

a collection of nerve cell bodies used for control and regulatory activities

Answer 2

ganglia

Question 3

a system wherein blood saturates the body and may be directly open to the environment at places like the digestive tract, instead of being sealed in blood vessels

Answer 3

open circulatory system

Question 4

an elongated structure containing the mouth and certain nervous and sensory organs, as well as an elongated foot that is used in attachment and locomotion

Answer 4

Head-foot

Question 5

contains the organs of digestion, circulation, reproduction,
and excretion

Answer 5

Visceral Mass

Question 6

encloses the visceral mass; secretes calcium carbonate and matrix to
form the exterior shell of a mollusk

Answer 6

Mantle

Question 7

a central feature of the molluscan biology; this cavity is formed by the mantle skirt, a double fold of mantle which encloses a water space; functions in gas exchange, excretion, elimination of digestive wastes, and release of reproductive products; serves as a respiratory chamber in all mollusks

Answer 7

Mantle Cavity

Question 8

ribbon-like structure covered with rows of small teeth; used for breaking down food before entering the digestive tract

Answer 8

Radula

Question 9

also referred to as the class of snails and slugs; recognized as the largestand most diverse class of Phylum Mollusca;

Answer 9

Class Gastropod

Question 10

elongated appendage which serves as a muscular feeding tube in some animals

Answer 10

e proboscis

Question 11

with close to 30,000 species, it is considered as the second largest molluscan class; this class includes clams, oysters, mussels, and scallops; a sheet-like mantle and a shell consisting of two valves cover 
these laterally compressed animals

Answer 11

Class Bivalvia

Question 12

eat particles of food from the surrounding water; through filtering the water, bivalves are valuable in removing bacteria from polluted water

Answer 12

suspension feeders

Question 13

organisms which have male sexual organs when young, then changes into having female sexual
organs later in life

Answer 13

protandric

Question 14

includes the octopus, squid, cuttlefish, and the nautilus; dubbed as the most complex mollusk and in many ways, the most complex invertebrates; the foot is incorporated into a funnel associated with the mantle
cavity and is used for jet-like locomotion

Answer 14

Class Cephalopoda

Question 15

one tentacle of male cephalopods

Answer 15

hectocotylus

Question 16

structures for encasing sperm in packers

Question 16

structures for encasing sperm in packers

Answer 16

spermatophores

Question 17

has a _________ for muscle contraction, sensory perception, memory, and decision-making

Answer 17

large brain

Question 18

a pigment-containing cell found in a wide range of animals which enables them to camouflage

Answer 18

Chromatophore

Question 19

powerful, beak-like structures for tearing food, and the radula rasps food, forcing it into the mouth cavity

Answer 19

jaws