Mollusks/Annelids

Question 1

Symmetry Type of Mollusks

Answer 1

Bilateral Symmetry

Question 1

Visceral Mass

Answer 1

Contains the internal organs

Question 2

Mantle

Answer 2

Delicate tissue that produces shell. Thin layer of tissue that covers the entire body.

Question 3

Foot

Answer 3

Usually contains the mouth and used for locomotion and food capture. Different forms for different animals

Question 4

Shell

Answer 4

Used for protection, but not all mollusks still retain it (eg. octopi)

Question 5

Diet (Mollusks)

Answer 5

Can be herbivores, carnivores, filter feeders, scavengers, or parisites.

Question 6

Radula

Answer 6

Tongue shaped structure with teeth all over. used to drill through animal shells or scrape algae off rocks.

Question 7

Gills in Clam and Oysters

Answer 7

Filter Food.

Question 8

Method of Respiration (Mollusks)

Answer 8

Usually gills

Question 9

Mantle Cavity

Answer 9

In snails and slugs. Lined with blood vessels as they have no gills.

Question 10

Type of Circulatory System (Mollusks)

Answer 10

Open Circulatory System.

Question 11

Sinuses

Answer 11

Blood goes through sinuses which lead to blood vessels

Question 12

Respiration Process & Where it is Located (Mollusks)

Answer 12

Oxygen and CO2 exchange in gills

Question 13

Nephridia

Answer 13

Tube shaped, ammonia leaves through here. Solid waste leaves through anus

Question 14

Simple Nervous System (Mollusks)

Answer 14

Ganglia near mouth, few nerve cords, simple sense organs. Eg. Clams

Question 15

Complex Nervous System (Mollusks)

Answer 15

Octopi. Very intelligent with well developed brains, can remember for long time.

Question 16

Reproduction (Mollusks)

Answer 16

Most have separate sexes and have external fertilization (eggs and sperm released into water), which develop into larvae. Some are hermaphrodites.

Question 17

Class Division Basis (Mollusks)

Answer 17

Divided based according to foot and shell

Question 18

Class Bivalvia

Answer 18

Two large shells, filter feeders, grows up to 2m diamater. Eg. Clams, oysters, mussels, scallops.

Question 19

Class Gastropoda

Answer 19

Translates to “stomach” “foot”. All have radula and are snails, and are shell-less or single shelled that move using muscular food located on ventral side. Eg. Slugs, ground snails

Question 20

Class Cephalopoda

Answer 20

Translates to “head” “foot”. Internal shell or no shell in return for speed, making them good hunters. Head attached to single foot which is divided into arms or tentacles. Eg. Octopi and squid.

Question 21

Septum

Answer 21

Internal walls that separate the segments of an annelid

Question 22

Habitat (Annelids)

Answer 22

Mostly in mud or oceans

Question 23

Nervous System (Annelids)

Answer 23

Most have brain and several nerve cords

Question 24

Pharynx

Answer 24

Catches prey and pumps food/soil into esophagus

Question 25

Esophagus

Answer 25

Tube where food/soil is pumped through

Question 26

Crop

Answer 26

Location where food is first stored

Question 27

Gizzard

Answer 27

Food is ground into smaller pieces

Question 28

Intestine

Answer 28

Digests food

Question 29

Nephridia

Answer 29

Filters fluid

Question 30

Type of Circulatory System (Annelids)

Answer 30

Closed Circulatory System

Question 31

Two Types of Blood Vessels (Annelids)

Answer 31

Dorsal - top, moves blood toward head of worm
Ventral - bottom, moves blood toward end of worm

Question 32

Aortic Arches

Answer 32

5 hearts of the Annelid

Question 33

Two Groups of Muscles (Annelids)

Answer 33

Longitudinal - front to rear, contract to make worm shorter/fatter
Circular - wrap around each body segment and contract to make the worm longer and thinner

Question 34

Reproduction (Annelids)

Answer 34

Most sexual, some hermaphrodites, some budding.

Question 35

Clitellum

Answer 35

When eggs are ready for fertilization, clitellum excretes a mucus ring in which sperm and eggs are released. Fertilization takes place inside ring, which slips off and forms a cocoon before hatching a few weeks later.

Question 36

Polychaetes

Answer 36

Many bristles. Eg. Marine bristle worm, bloodworm, sandworm

Question 37

Hirudinae

Answer 37

Parasite that sucks blood and bodily fluids of host. Used to reduce swelling after surgery and secretes a fluid that stops blood from clotting. Ex. Leech

Question 38

Oligochaetes

Answer 38

Few Bristles. Sold in pet stores as food. Eg. Earthworm, tubiflex worm

Question 39

Ecological Significance of Annelids

Answer 39

Enriches soil, slows down erosion, aerates soil, helps decompose plant matter, makes passageways for plant roots and water, increases nitrogen fixation.