Biol 111 Lab 8 - Mcgill

Front 1

Phylum mollusca

Back 1

Large group including snails/slugs, "shellfish" and octopus/squid. Lack segmentation and most have an open circulatory system (exception: cephalopods)

Front 2

Shell (Gastropod)

Back 2

Composed of calcium carbonate and proteins secreted from the mantle.

Front 3

Operculum (Gastropod)

Back 3

Hard disc on the dorsal surface of gastropod's foot which, when retracted, acts like a lid to seal the snail within its shell.

Front 4

Foot (Gastropod)

Back 4

Used for locomotion. Specialized glands produce and secrete mucus.

Front 5

Tentacles (Gastropod)

Back 5

Gastropods have two pairs on their head used primarily for olfaction.

Chemoreceptors are located within the tentacles' epidermis.

Front 6

Superior tentacles

Back 6

Chemoreceptors used to detect airborne chemicals.

Also possess weak photoreceptors used to detect differences in light levels.

Front 7

Inferior tentacles

Back 7

Chemoreceptors used to detect terrestrial chemicals.

Front 8

-Taxis

Back 8

Refers to movement in a particular direction.

Front 9

How do terrestrial and aquatic mollusks respire?

Back 9

Terrestrial mollusks: exchange gases across their mantle. Must remain moist to avoid desiccation.

Aquatic mollusks: use of gills.

Front 10

Sexually, most gastropods are classified as ______.

Back 10

Hermaphrodites.

Front 11

Pheromones

Back 11

Chemical attractant.

Front 12

Phylum arthropoda

Back 12

Most complex and diverse of invertebrates. Exhibit symmetry, segmentation, an exoskeleton, joint appendages and cephalization.
e.g. Crayfish.

Front 13

Crayfish exhibit _____ symmetry.

Back 13

Bilateral.

Front 14

Body covering (Crayfish)

Back 14

Composed of chitin which acts as a protective outer layer (exoskeleton) to which muscles are attach.

Exoskeletons are inextensible; therefore molting is necessary for growth.

Front 15

Chitin (Crayfish)

Back 15

Organic compound secreted by underlying epidermal cells and made hard by the deposition of calcium carbonate.

Front 16

Body regions (Crayfish)

Back 16

Cephalothorax and abdominal regions.

Front 17

Cephalothorax (Crayfish)

Back 17

Consists of the head and thorax, which are covered by the carapace and divided by the cervical groove.

Front 18

Carapace (Crayfish)

Back 18

Fused dorsal shield which covers the crayfish's head and thorax.

Front 19

Compound eyes (Crayfish)

Back 19

Eyes that contain more than one lens.

Front 20

Rostrum (Crayfish)

Back 20

Anterior pointed projection of the dorsal shield which separate the compound eyes.

Front 21

Serial homology

Back 21

When there are similar structures in different segments of an organism, perhaps having different functions.

Front 22

Antennules (Crayfish)

Back 22

Short, branched filaments for touch and taste and equilibrium.

Front 23

Statocysts (Crayfish)

Back 23

Balancing organs located at the bases of the antennules.

Front 24

Antennae (Crayfish)

Back 24

Long slender filaments with a short fan-like branch for touch and taste.

Front 25

Nephridiopore (Crayfish)

Back 25

Excretory pore from the green glands located at the base of the antennae.

Front 26

Mandibles (Crayfish)

Back 26

Jaws used for crushing and chewing food. Mouth is located between the mandibles.

Front 27

Maxillae (Crayfish)

Back 27

Handle food and deliver it to the mandibles.
Posterior pair has a gill bailer to keep water flowing over the gills.

Front 28

Maxillipeds (Crayfish)

Back 28

3 pairs used for touch, taste and food handling.

Front 29

Walking legs (Crayfish)

Back 29

5 pairs.
Chelipeds (1st pair) has large pincers for defense and capturing/crushing prey.
2nd and 3rd pair have small pincers for locomotion.

Front 30

Swimmerets (1st pair)

Back 30

Males: enlarged to form a tube for transferring sperm.

Females: Reduced and serve no apparent function.

Front 31

Swimmerets (2nd pair) (Crayfish)

Back 31

Males: Hardened to help transfer the sperm.
Females: Hold fertilized eggs during incubation.
Both: Aid in respiration by helping circulate water.

Front 32

Swimmerets (3,4,5th pairs) (Crayfish)

Back 32

Biramous (branched).
Both: Used for water circulation
Female: Aid in carrying eggs.

Front 33

Swimmerets (6th pair) (Crayfish)

Back 33

Uropods (flat, broad and fan-shaped) + Telson (last abdominal segment) = tail fan (paddle for backward swimming)

Front 34

Gills (Crayfish)

Back 34

Thin, feathery structure involved in gas exchange during respiration.

Front 35

Crayfish and other anthropods have an ____ circulatory system.

Back 35

Open; therefore there are no veins. Blood enters the heart via ostia (holes) and is pumped out through seven main arteries to the body.

Front 36

Hemocyanin

Back 36

Oxygen-carrying pigment in blood plasma of antrhopods; carries copper thus giving blood a transparent colour.

Front 37

Digestive glands (Crayfish)

Back 37

Soft, cream-coloured glands on both sides of the heart responsible for enzymatic digestion and absorption of nutrients missed by the stomach.

Front 38

Cardiac stomach (Crayfish)

Back 38

Larger of two chambers responsible for initial enzymatic digestion of food; lined with a cuticle and chitinous teeth (gastric mill).

Front 39

Gastric mill (Crayfish)

Back 39

Chitinous teeth within the cardiac stomach responsible for pulverizing, straining and sorting food.

Front 40

Pyloric stomach (Crayfish)

Back 40

Responsible for separating out indigestible food material and sending it out to the intestine.

Front 41

Intestine (Crayfish)

Back 41

Passes waste food materials from the pyloric stomach to the anus.

Front 42

Mouth (Crayfish)

Back 42

Starting point of digestive system. Surrounded by specialized appendages for catching/shredding food.

Front 43

Statocyst (Crayfish)

Back 43

Consists of a fluid-filled chamber lined with setae and statoliths (sand grains); provides a sense of balance and equilibrium.

Front 44

Green glands (Crayfish)

Back 44

Circular, green (in live specimens) organs responsible for the removal of unwanted substances from the blood and excretion of waste fluid from the body.

Front 45

Abdominal flexor muscles (Crayfish)

Back 45

Muscles which flank the intestine and its overlying blood vessel located along the midline. When contracted, they curl the abdominal region.

Front 46

Abdominal extensor muscles (Crayfish)

Back 46

Paired, long, and dorsally located. When contracted, they straighten the abdominal region.