PHYLUM MOLLUSCA

Question 1

Name the characteristics of his phylum

Answer 1

Triploblastic, bilaterally symmetrical, unsegmented, true coelom, protostomes

Question 2

What is some general information about this phylum?

Answer 2

Economy, flatworms are in the 3rd dimension, visceral mass, specialized organs

Question 3

What does the osphradia do?

Answer 3

Monitor the water flow over the gills/ctenidia

Question 4

What is the name of the generalised mollusc?

Answer 4

Archimollusc

Question 5

What is a radula, its function and what is it supported by?

Answer 5

Teeth-like conveyer belt for feeding. Primitive grazers have it. Supported by odontophores

Question 6

What is the shell secreted by and how many layers are there?

Answer 6

The mantle, there are 3

Question 7

Name the layers of the shell

Answer 7

Periostracum, prismatic & nacreous

Question 8

Describe the periostracum layer?

Answer 8

Organic layer, dark conchiolin

Question 9

Describe the prismatic layer?

Answer 9

CaCO2, prisms in the protein matrix

Question 10

Describe the nacreous layer?

Answer 10

Plate-like, CaCO2 crystals, pearly

Question 11

How are pearls formed?

Answer 11

Particles become trapped between the nacreous and epidermis layers and irritates the mollusc. It coats it in calcium carbonate

Question 12

The circulatory system in molluscs is open, true or false?

Answer 12

True, except in Cephalopoda

Question 13

How many oracles and ventricles does mollusca have?

Answer 13

2 oracles, one ventricle

Question 14

Name the elements of the c.s

Answer 14

some blood vessels, haemocyanin and the heart is in the coelomic cavity.

Question 15

What is the pericardium?

Answer 15

The coelomic cavity

Question 16

What is haemocyanin?

Answer 16

A protein containing copper that transports oxygen in invertebrates

Question 17

What parts are ciliated in the digestive system of mollusca?

Answer 17

All parts

Question 18

Where do the salivary glands open up to?

Answer 18

The oesophagus

Question 19

Describe the d.s process

Answer 19

Salivary glands secrete mucus, mucus/food string is formed in oesophagus, pulled into stomach by cilia, rotated, protostyle, intra/extra cellular digestion

Question 20

What is the protostyle?

Answer 20

Food laden mucus mass

Question 21

What is the excretion process?

Answer 21

The metanephridia drain pericardial cavity and empty into the mantle cavity

Question 22

What do the gonads arise from?

Answer 22

The coelom

Question 23

What is the one word that describes reproduction in mollusca

Answer 23

Parthenogenesis

Question 24

What is parthenogenesis?

Answer 24

Reproduction via unfertilized gametes

Question 25

Describe the reproduction process

Answer 25

Egg and sperm are released into the environment and fertilization occurs there

Question 26

What is the nervous system like?

Answer 26

Advanced, has sense organs, nerve ganglia, paired pedal/palial nerve cords, dorsal/ventral cords