Questions for discussion
1. What physical features are changing as a frog progresses from tadpole to adult?
The jaw changes shape, tail recedes, tongue for catching flies develops, hind legs and then front legs begin to grow, and lungs develop as gills disappear. This is merely a list of some of the most obvious changes that occur as a frog undergoes metamorphosis and is not intended to be an exhaustive description.
2. What are some links among the changes of a frog’s physical characteristics and its habitat?
Animals morph so they can survive in a new environment. Tadpoles often move from aquatic to terrestrial environments as they morph into adult frogs, so their bodies must support different ways of eating, breathing, and moving.
3. How are life cycles of plants and animals similar?
Plants have similar life cycles to frogs because they both change shape during their lives and have a stage where they don’t look like the adult stage (tadpole in the case of the frog, seedling in the case of the plant).
4. What are the stages in the life of a frog?
For frogs, it would be egg–>tadpole–>froglet (young frog)–>adult frog. For other animals, answers will vary.
5. Are frogs the only animal to go through metamorphoses during their life cycle?
No, butterflies and moths undergo complete metamorphoses, and dragonflies and many fish experience incomplete metamorphoses (as well as various other organisms).
6. Do humans go through metamorphoses? How do you know?
Although humans’ body shapes grow during their lives, they don’t change.
Allow the students to select the tool(s) they find most appropriate for capturing and sharing their pseudocode. Encourage them to use text, videos, images, sketch notes, or another creative medium.
3. Create phase
1. Build a model of a tadpole (larva)
Students will start to build a tadpole with only eyes, a long tail, and, at first, no front legs. Have them take a picture of this stage or sketch it in order to document it before they morph it into the young frog.
2. Build a young frog model (froglet).
Students will follow the building instructions to morph the tadpole into a young frog that can move if activated by a program. Let the students describe the changes they note as the model progresses.
One important, new feature that has changed in the young frog is the development of back legs. The walk module used in the project uses gears. These gears move the back legs.
Students should once again document their models using pictures and/or sketches.