Student Preconceptions
Students often have several misconceptions concerning the caterpillars and butterflies. Here are a few which teachers should attend to and correct should they arise.
Description of a student preconception (naive conception, misconception, incomplete conception):
The caterpillar has many, many legs.
Correct conception by the end of the unit:
A caterpillar only has six true legs just as any insect in any stage would have. The other leg-like structures are prolegs and act as pedestals for balance.
Description of a student preconception (naive conception, misconception, incomplete conception):
The little pellets in the caterpillar cups are eggs.
Correct conception by the end of the unit:
It is only in the adult phase that eggs are laid. This is the butterfly phase.
Description of a student preconception (naive conception, misconception, incomplete conception):
The Painted Lady caterpillars "spin" cocoons.
Correct conception by the end of the unit:
The Painted Lady is a butterfly and as such forms a chrysalis. Cocoon is a term applied to the pupa stage of moths, whereas the pupa stage of the butterfly is called a chrysalis. A cocoon is swathed in silk, where a chrysalis only has a silk button to hang from. The pupa itself is naked.
Description of a student preconception (naive conception, misconception, incomplete conception):
Only insects have life cycles.
Correct conception by the end of the unit:
The truth is that every living thing has a life cycle. Life cycles vary in looks and duration but all living things go through the stages nonetheless.
Description of a student preconception (naive conception, misconception, incomplete conception):
Spiders, pill bugs, and worms are insects.
Description of a student preconception (naive conception, misconception, incomplete conception):
Insects have certain specific characteristics: six legs, a head, a thorax, an abdomen, two sets of wings (at some stage in their life cycle) and antennae. If an invertebrate does not have these characteristics, it is not an insect.