Lophotrochozoa III

Question 1

Three lophotrochozoa phylum

Answer 1

Annelids
Flatworms
Molluscs

Question 2

3 main classes in mollusc phylum

Answer 2

Gastropod
Bivalves
Cephalopod

Question 3

How many classes within mollusc phylum?

Answer 3

8

Question 4

How are Gastropoda characterised

Answer 4

Slow grazers

Question 5

How are bivalves characterised

Answer 5

Filter feeders

Question 6

How are cephalopods characterised

Answer 6

Active hunters

Question 7

How many species in mollusc phylum?

Answer 7

100 000 species (second biggest phylum)

Question 8

What type of gut do molluscs have?

Answer 8

Through gut

Question 9

What characteristic have molluscs lost that the other lophotrochozoa phylum Annelida have?

Answer 9

Segmentation

Question 10

What connects the mollusc to its shell?

Answer 10

Outermost layer of tissue on their bodies called the mantle

Question 11

How is mollusc shell built?

Answer 11

Specialised cells in the mantle build the shell using proteins and minerals.

Question 12

Conchin

Answer 12

Protein substance which is the organic basis of mollusc shells and secreted by the molluscs outer epithelium (the mantle)

Question 13

Mantle

Answer 13

Tissue layer (outer epithelium) on molluscs which secretes the shell

Question 14

Periostracum

Answer 14

Waterproof outermost layer of molluscan shells

Composed of quinine tanned proteins and is base for calcium carbonate crystals to be deposited onto. It protects the shell from dissolving.

Question 15

How do molluscs breathe?

Answer 15

Molluscs have either done pair of gills or a singular gill and they are located within the mantle cavity.

Question 16

Radula

Answer 16

Feeding structure of a mollusc composed of small teeth that scrape food particles off of surface and draw them into the mouth

Question 17

Odontophore

Answer 17

Cartilaginous projection in the mouth of a mollusc which supports the radula

Question 18

Torsion

Answer 18

Gastropod synapomorphy that occurs during larval development. Transformation of symmetric body plan to an asymmetric body plan due to rotation of the visceral mass and mantle by 180 degrees

Question 19

Issue with torsion

Answer 19

Flow of waste products near sensory organs as the anus is in close proximity with the head and gills.

Question 20

Why might torsion have evolved?

Answer 20

X

Question 21

Evolutionary advantage of torsion?

Answer 21

X

Question 22

How were the issues with torsion solved?

Answer 22

1. Molluscan shells have holes through which water and waste can flow out of
2. Détorsion
3. Loss of right gill to allow for a sideways flow of water

Question 23

What characteristic have bivalves lost that Gastropoda have?

Answer 23

Radula

Question 24

What type of feeders are bivalves?

Answer 24

Filter feeders

Question 25

Features of bivalves

Answer 25

``` No radula Two shells Ligament to open shell One foot Filter feeders ```

Question 26

Do bivalves have gills

Answer 26

Yes

Question 27

What bivalve has eyes?

Answer 27

Scallops have approximately 60 eyes and use layers of guanine crystals at the back of the eye to get constructive inference

Question 28

4 examples of cephalopod

Answer 28

Nautilus Cuttlefish Squid Octopus

Question 29

Four features that make cephalopods more advanced?

Answer 29

Closed bliss system Large brain Well developed eyes Jet propulsion

Question 30

Siphon

Answer 30

Cephalopod organ used to expel water for locomotion