Phylum Mollusca Flashcards
1
Q
Body divided into 3 parts called ?
A
- Mantel
- visceral mass
- head foot
2
Q
What is the mantel ?
A
A fold of skin that lies between the shell and the visceral mass.
Function- produces shell by special gland
3
Q
What is the visceral mass ?
A
It contains the heart , digestive track and other organs
4
Q
What is the “head foot” ?
A
Contains head and foot . Lower part of mouth forms broa tongue covered by chitin oud membrane(radula) which has teeth .
5
Q
Gastropoda undergoes torsion. What is torsion ?
A
It is the rotation of the visceral mass by 180* anti-clockwise direction
6
Q
Torsion should not be confused with coiling . What is coiling ?
A
Torsion causes the visceral mass to develop a dorsal hump and is arranged by dorsal coiling . The shell is also coiled as a result
7
Q
Main features of Molluscs
A
- Soft
- Unsegmented body
- Protected by shell usually
