2/17/20

Question 1

class of Mollusca with a closed circulatory system

Answer 1

class Cepholapoda

Question 2

method of reproduction used by all of Phylum Mollusca

Answer 2

sexual reproduction

Question 3

course of Mollusc development

Answer 3

in aquatic species, eggs generally hatch into trochophore larva and then into a veliger larva

Question 4

trochophore definition and function

Answer 4

ciliated larva (aids in locomotion and feeding)

Question 5

stage that all molluscs but cephalopods progress into after the trochophore stage

Answer 5

veliger

Question 6

structures present in veliger larva

Answer 6

beginnings of foot, mantle, and shell

Question 7

only member of Phylum Mollusca that does not develop into a veliger

Answer 7

class Cepholapoda

Question 8

general characters of class Gastropoda

Answer 8

about 80,000 species, mostly marine but many freshwater/terrestrial, slow-moving, relatively sedentary, shell as self-defense, cephalized head

Question 9

developmental process underwent by Gastropods

Answer 9

torsion

Question 10

torsion process

Answer 10

changing of the position of body parts during development; go from a linear gut with gills in the back to a loopy gut with anus and gills near the mouth

Question 11

pros of torsion

Answer 11

gills are anterior and can sample water, entire body can be pulled within shell

Question 12

cons of torsion

Answer 12

anus is right above the head/mouth/gills :/

Question 13

process underwent by some Gastropods where torsion is reversed during development

Answer 13

detorsion

Question 14

class of Phylum Mollusca that contains most of Mollusca diversity

Answer 14

class Gastropoda

Question 15

process in some Gastropods in which the shell is lifted upwards and back to help with balance

Answer 15

coiling

Question 16

impacts of torsion and coiling on Gastropod structure

Answer 16

internal asymmetry of organs, many “paired” organs are lost on the right side

Question 17

class of Phylum Mollusca known as Chitons

Answer 17

class Polyplacophora

Question 18

general characters of class Polyplacophora

Answer 18

about 1000 extant species, generally live in rocky intertidal zones, radula reinforced with iron

Question 19

structure of class Polyplacophora

Answer 19

dorsal shell made of 7-8 separate plates surrounded by girdle of mantle, gills surround the foot

Question 20

class of Phylum Mollusca that includes mussels, clams, oysters, and scallops

Answer 20

class Bivalvia

Question 21

general characters of Bivalves

Answer 21

about 9000 species, mostly marine, have lost cephalization and the radula, filter feeders

Question 22

method by which Bivalves combine feeding with breathing

Answer 22

suck water in through incurrent siphon and over gills, which extract oxygen and capture food particles on layer of mucus before cilia move food towards labial palps, which then direct food into the mouth

Question 23

organ in Bivalvia used primarily for digging

Answer 23

foot

Question 24

muscles in Bivalvia that contract to close the shell

Answer 24

adductor muscles

Question 25

class of Phylum Mollusca that includes, octopuses, squids, cuttlefish, and nautiluses

Answer 25

class Cephalopoda

Question 26

general characters of class Cephalopoda

Answer 26

all very intelligent marine predators, strong beaklike jaws, mantle used for jet propulsion, many have long tentacles/arms with suckers

Question 27

only species of class Cephalopoda with an external shell

Answer 27

nautiluses

Question 28

species of class Cephalopoda where the shell rests under the mantle

Answer 28

cuttlefish

Question 29

species of class Cephalopoda where the shell is a thin strip called the “pen”

Answer 29

squids

Question 30

species of class Cephalopoda that has lost the shell entirely

Answer 30

octopuses

Question 31

structure of circulatory system in class Cephalopoda

Answer 31

two branchial hearts pump deoxygenated blood to gills, systemic heart pumps oxygenated blood to the rest of the body

Question 32

reproductive process of class Cephalopoda

Answer 32

separate sexes, no larva stage (direct development), very little parental care (except octopuses)

Question 33

Phylum united by the trait of a molting cuticle

Answer 33

Phylum Ecdysozoa

Question 34

Phylum of Ecdysozoa known as horsehair worms

Answer 34

Phylum Nematomorpha

Question 35

general characters of phylum Nematomorpha

Answer 35

about 320 species, very long and thin, adults are free-living but all juveniles parasitize arthropods (emerge once in water)

Question 36

Nematomorpha do/don’t have sexual separation

Answer 36

do

Question 37

Phylum of Ecdysozoa known as roundworms

Answer 37

Phylum Nematoda

Question 38

general characters of Phylum Nematoda

Answer 38

estimated 1,000,000 species, about half are parasitic, live in every habitat on earth, account for 80% of individual animals on earth

Question 39

structure of Nematodes

Answer 39

unsegmented, pseudocoelomate, generally small, covered in noncellular cuticle made from collagen, longitudinal muscles, simple morphology (mouth, pharynx, intestine, anus, reproductive organs), anterior nerve ring

Question 40

free-living Nematodes generally go through ____ molts before adulthood

Answer 40

four

Question 41

“model” organism of Nematoda

Answer 41

C. elegans