Inside its beak an octopus has a rasping tongue that is used to tear apart food. Which gastropod structure is this analogous to?

Question

A.  Mantle
B.  Shell
C.  Radula
D.  Nephridium

Clarify Question
· What is the key concept addressed by the question?
· What type of thinking is required?

Gather Content
· What do you already know about mollusk feeding?

Choose Answer
· Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?

Reflect on Process
· Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?

Answer 1

C.  Radula

Clarify Question
· What is the key concept addressed by the question?
        o This question addresses mollusk feeding.
· What type of thinking is required?
        o This question is asking you to take what you already know and apply it to this unfamiliar situation.

Gather Content
· What do you already know about mollusk feeding?
        o Gastropods are a type of mollusk – they are the snails and slugs.
        o Mollusks feed using the radula – a rasping, tonguelike structure.
        o The radula consists of dozens to hundreds of microscopic, chitinous teeth arranged in rows on an underlying membrane and lies in a chamber at the anterior end of the gut.
        o The radula can be protruded through the mouth and move something like a sanding belt over what is being rasped. Benthic mollusks use their radulae to scrape up algae and other food materials.
        o In some predatory gastropods the radula is modified to drill through clam shells. In cone snails the radula has been transformed into a venomous harpoon that can be lethal to humans.
        o Bivalves are the only mollusks that have no radula – they use gills to filter food out of the water.

Choose Answer
· Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?
        o The beak of an octopus is its feeding structure.
        o The feeding structure of a gastropod is the radula.

Reflect on Process
· Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?
        o The question required you to take what you already know and apply it to this unfamiliar situation.
        o Did you recognize that the radula is the feeding structure of gastropods? Are you surprised to find that slugs and snails have “teeth”?