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    Puzzling Phenomenon or Anchoring Event |  Essential Question |  Gapless Explanation |  Alternative Conceptions

    Puzzling Phenomenon or Anchoring Event

    Time-lapse video of Monarch Butterfly metamorphosis for use as phenomenon.  Also available in streaming versions on YouTube and on Vimeo.


    Essential Question

    • What does it mean to be alive?


    • How do living organisms interact with their environment?

    • How are all living organisms related?

    Gapless Explanation

    Big Ideas:

    • Structure and function (Diversity of Forms)
    • Insect needs
    • Patterns of Growth and Reproduction

    Gapless Explanation of Butterfly Metamorhosis (Adult Level):

    Observing the Life Cycle of a Butterfly, students observe one organism over time and compare its early development (caterpillar) to its later development (butterfly). A fundamental observation skill in science is comparing and contrasting.

    All butterflies have "complete metamorphosis." To grow into an adult they go through 4 stages: egg, larva, pupa and adult. Each stage has a different goal - for instance, caterpillars need to eat a lot, and adults need to reproduce.

    A butterfly starts life as a very small, round, oval or cylindrical egg.  The coolest thing about butterfly eggs is that if you look close enough you can actually see the tiny caterpillar growing inside of it. Some butterfly eggs may be round, some oval and some may be ribbed while others may have other features. The egg shape depends on the type of butterfly. 

    When the egg finally hatches the larvae emerges and the organism begins the second phase of its life.  The common term for Butterfly larvae is “caterpillars.” Caterpillars do not stay in this stage for very long and mostly, in this stage all they do is eat.  When the egg hatches, the caterpillar will start his work and eat the leaf on which they were born. (Butterflies lay their eggs on the type of leaf the caterpillar will eat.) Since they are tiny and can not travel to a new plant, the caterpillar needs to hatch on the kind of leaf it will to eat.  

    The pupa stage is the third stage of a butterfly’s life.  As soon as a caterpillar is done growing and they have reached their full length/weight, they form themselves into a pupa, also known as a chrysalis.  From the outside of the pupa, it looks as if the caterpillar may just be resting, but the inside is where all of the action is.  Inside of the pupa, the caterpillar is rapidly changing.  Within the chrysalis the old body parts of the caterpillar are undergoing a remarkable transformation, called ‘metamorphosis,’ to become the parts that make up the butterfly that will emerge. Tissue, limbs and organs of a caterpillar have all been changed by the time the pupa is finished, and is now ready for the final stage of a butterfly’s life cycle. 

    When the caterpillar has done all of its forming and changing inside the pupa an adult butterfly emerges.  When the butterfly first emerges from the chrysalis, both of the wings are soft and folded against its body. The butterfly waits for its wings to dry, and pumps a liquid called hemolymph into them so that they become big and strong. Once fit for flight, this brilliant bug then takes to the air in search for flowers to feed on and for other butterflies to mate with. And that’s the cycle complete – and ready to start all over again!

    Gapless Explanation of Butterfly Metamorhosis  (Elementary Level):

    Butterflies go through a life cycle. There are four stages. The first stage is the eggs. This is where a girl butterfly lays eggs. She lays them on a leaf. The second stage is the caterpillar. This is where the eggs hatch. It takes about five days for the eggs to hatch. A caterpillar then comes out. At this stage, the caterpillar eats all the time. It also grows really fast. Once it is all the way grown, the third stage starts. This stage is the chrysalis. The caterpillar makes a chrysalis. The caterpillar is inside the chrysalis. Inside the chrysalis, it starts to change. It soon changes into a butterfly. Once the caterpillar has changed into a butterfly, the fourth stage starts. This is also that last stage in the life cycle.  The fourth stage is the butterfly. A butterfly comes out of the chrysalis. It can now learn to fly. It can also find a mate. When it finds a mate, it lays eggs. Then the lifecycle process starts all over again..


    Disciplinary Core Ideas

    All organisms have external parts. Different animals use their body parts in different ways to see, hear, grasp objects, protect themselves, move from place to place, and seek, find, and take in food, water and air. Plants also have different parts (roots, stems, leaves, flowers, fruits) that help them survive and grow.

    There are many different kinds of living things in any area, and they exist in different places on land and in water.

    Plants depend on animals for pollination or to move their seeds around.

    Performance Expectations

    Develop a simple model that mimics the function of an animal in dispersing seeds or pollinating plants. 2-LS2-2 

    Make observations of plants and animals to compare the diversity of life in different habitats. 2-LS4-1


    Age Appropriate Science and Engineering Practices

    As Stated in Standards Adapted for K–2
    Asking questions  (science) / Defining problems (engineering)  Wondering  (science) / Deciding the 'rules' (engineering)
    Developing and using models Drawing diagrams and building models to represent how things work.
    Planning and carrying out investigations Doing “exploriments”
    Analyzing and interpreting data Comparing and looking for patterns
    Using mathematical and computational thinking Counting and measuring
    Constructing explanations (science) / designing solutions (engineering) Describing what happened (science) / Tinkering (engineering)
    Engaging in argument from evidence "I think ____ because I see or know ____."
    Obtaining, evaluating, and communicating information Writing, drawing, or talking (acting out) about what we know, read, and understand about new discoveries (things) (ELA connections)

    Alternative Conceptions

    There is a predictable pattern in students’ development of the concept “living.”  From birth to age 5, students have almost no concept of living things; from 6 to 7, students believe things that are active or make noise are alive; from ages 8 to 9, students classify things that move as alive; from 9 to 11, students identify things that appear to move by themselves (including rivers and the Sun) as living; and past age 11, through adulthood, animals or animals and plants are considered living. 

    Some research indicates that when a student is in second grade, there is a shift in his or her understanding of organisms, from representations based on perceptual and behavioral features to representations in which central principles of biological theory are most important.  It is not until around the age of 9 or 10 that children begin to understand death as the cessation of life processes.

    People of all ages have a much narrower definition of animal that biologists do.  Students typically think of animals as terrestrial mammals. Students’ ideas about animal qualities commonly include the following:  having four legs, being large I size, having fur, making noise, and living on land.  Children do not often think of humans as animals; rather, they are contrasted with animals. Humans, insects, birds, and fish often are thought of as alternatives other than animals, not as subsets of animals.

    (See full article on "Common Alternative Conceptions About Insects.")