PHYLUM MOLLUSCA Flashcards Preview

Invertebrates > PHYLUM MOLLUSCA > Flashcards

Flashcards in PHYLUM MOLLUSCA Deck (26):
1

Name the characteristics of his phylum

Triploblastic, bilaterally symmetrical, unsegmented, true coelom, protostomes

2

What is some general information about this phylum?

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

3

What does the osphradia do?

Monitor the water flow over the gills/ctenidia

4

What is the name of the generalised mollusc?

Archimollusc

5

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

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

6

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

The mantle, there are 3

7

Name the layers of the shell

Periostracum, prismatic & nacreous

8

Describe the periostracum layer?

Organic layer, dark conchiolin

9

Describe the prismatic layer?

CaCO2, prisms in the protein matrix

10

Describe the nacreous layer?

Plate-like, CaCO2 crystals, pearly

11

How are pearls formed?

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

12

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

True, except in Cephalopoda

13

How many oracles and ventricles does mollusca have?

2 oracles, one ventricle

14

Name the elements of the c.s

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

15

What is the pericardium?

The coelomic cavity

16

What is haemocyanin?

A protein containing copper that transports oxygen in invertebrates

17

What parts are ciliated in the digestive system of mollusca?

All parts

18

Where do the salivary glands open up to?

The oesophagus

19

Describe the d.s process

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

20

What is the protostyle?

Food laden mucus mass

21

What is the excretion process?

The metanephridia drain pericardial cavity and empty into the mantle cavity

22

What do the gonads arise from?

The coelom

23

What is the one word that describes reproduction in mollusca

Parthenogenesis

24

What is parthenogenesis?

Reproduction via unfertilized gametes

25

Describe the reproduction process

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

26

What is the nervous system like?

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