Ch. 35 – Mollusks & Annelids Mollusks and annelids are grouped together because they were the 1 st organisms to develop a true coelom. – This suggests that these two groups of animals may have evolved from a common ancestor. The coelom provides space for a circulatory system to function without interference from other organs. They can contract muscles without hindering the movement of food through the gut. Both have the same 1 st stage in larva development which is
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Ch. 35 – Mollusks & Annelids Mollusks and annelids are grouped together because they were the 1 st organisms to develop a true coelom. – This suggests.
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Ch. 35 – Mollusks & Annelids Mollusks and annelids are grouped
together because they were the 1st organisms to develop a true coelom.– This suggests that these two groups of
animals may have evolved from a common ancestor.
The coelom provides space for a circulatory system to function without interference from other organs. They can contract muscles without hindering the movement of food through the gut.
Both have the same 1st stage in larva development which is called a trochophore.
Phylum: Mollusca–Snails, clams, octopuses,
oysters, squids–Video–Mollusk is Latin for “soft”–Most have a shell to protect
them and are soft inside the shell.
–Develop from a trochophore larva which is a free-swimmer. Cilia helps them swim.
Mollusk CharacteristicsMost are filter feeders (100,000