Mollusca and Echinodermata

Question 1

Morphogenesis

Answer 1

development and origin of morphological features/characteristic
involves specific change in cell shape, position and survival
4th step of embryonic development

Question 2

How is body shape determined through morphogenesis?

Answer 2

through the survival, position and shape of cells

Question 3

Mollusca

Answer 3

Protostome
usually bilateral but are extremely diverse
gills
Open circulation
Complete gut

Question 4

Shared mollusc features

Answer 4

• Coelomate
• Triploblastic
• non-segmented
• 3 body regions, head, foot, and visceral body region
• mantle, radula, mucus,

Question 5

Mantle

Answer 5

extension of the dorsal body wall, covers visceral mass that forms a muscular flap

Question 6

Radula

Answer 6

horned, ribbon-like structure in the mouth

Question 7

Mucus

Answer 7

protects skin, anti-predator and could be toxic

Question 8

3 types of mollusca

Answer 8

Gastropoda, Bivalvia, Cephalopoda

Question 9

Gastropoda function and mantle

Answer 9

crawling/holding
full or partially hidden under shell

Question 10

Bivalvia function and mantle

Answer 10

digging, burrowing
brightly coloured to protect against sunlight

Question 11

Cephalopoda function and mantle

Answer 11

tentacles for swimming
mantle is all that is seen behind head

Question 12

Chromotophores in Cephalopoda

Answer 12

pigment in the mantle used for changing colour, defence and communication

Question 13

Echinodermata shared features

Answer 13

Deuterostomes
Pentaradial symmetry
Hydrostatic skeletons (WVS)
nerve ring with radial nerves
regeneration capability
excretion bia Tiedemann’s bodies