activity 27 Emerging Adults BROWARD COUNTY ELEMENTARY SCIENCE BENCHMARK PLAN Grade K Quarter 3 Activity 27 SC.F.1.1.3 The student describes how organisms change as they grow and mature. SC.H.1.1.1 The student knows that in order to learn, it is important to observe the same things often and compare them. ACTIVITY ASSESSMENT OPPORTUNITIES The following suggestions are intended to help identify major concepts covered in the activity that may need extra reinforcement. The goal is to provide opportunities to assess student progress without creating the need for a separate, formal assessment session (or activity) for each of the 40 hands-on activities at your grade. 1. Remind students that they saw the butterflies go into the chrysalises as larvae and come out as full-grown butterflies. Ask, What is the name for this dramatic change? (It is called metamorphosis.) Then ask, Is the pupa stage really a resting stage when the butterfly is in the chrysalis? (No, it can t be called rest because so many changes are occurring inside the chrysalis during that time.) 2. Use the Activity Sheet(s) to assess student understanding of the major concepts in the activity. In addition to the above assessment suggestions, the questions in bold and tasks that students perform throughout the activity provide opportunities to identify areas that may require additional review before proceeding further with the activity. broward county hands-on science Quarter 3 263
264 activity 27 Emerging Adults
activity 27 Emerging Adults OBJECTIVES The students observe the adult butterflies emerging from the pupal stage and take note of how the adults differ from the larvae. The students observe the butterflies emerge from their chrysalises learn about the process of metamorphosis discuss the difference between the adults and the larvae SCHEDULE About 40 minutes, when at least eight butterflies have emerged from their chrysalises VOCABULARY metamorphosis MATERIALS For each student 1 Activity Sheet 27 1 magnifier For the class 1 book, Butterflies and Moths 3 butterfly feeder vials 1 butterfly tower, with butterfly pupae and emerging adults (from Activity 25) 8 containers, 8-oz, with lids 1 dropper, plastic flowers, cut (optional)* 1 overhead projector* 1 poster, Life Cycle of the Monarch Butterfly 1 spoon, plastic 1 bag sugar cubes 1 transparency, Adult Butterfly water, tap* *provided by the teacher PREPARATION 1 2 3 4 5 6 Prepare the feeding solution before the adult butterflies emerge, which will be 7 10 days after the first butterfly chrysalis forms. Dissolve three sugar cubes in 1 cup of water that has been left to sit out for at least 24 hours, and use a spoon to stir well. Follow the directions in the Materials Management section to make butterfly feeders. Also, fill a dropper with this solution. If desired, obtain some flowers, such as chrysanthemums, and place them in a sturdy vase or jar in the bottom of the butterfly tower. Once the butterflies emerge, drip sugar solution on these daily to allow butterflies to feed off the flowers, as they do in the wild. Obtain the use of an overhead projector. Make a copy of Activity Sheet 27 for each student. Hang the Life Cycle of a Monarch Butterfly poster where all students can see it. Shortly before the activity, place one adult butterfly in each of eight 8-oz containers, and cover with lid. (If enough butterflies have successfully emerged to give each team of two one to study, prepare all 16 containers.) broward county hands-on science Quarter 3 265
To place a butterfly in a container, reach into the butterfly tower with a container in hand, and trap a butterfly against the wall of the tower (see Figure 27-1). Being careful not to open the door of the tower too much, slip the lid over the container, trapping the butterfly inside. Close securely. Note: Do not leave these containers in direct sunlight for long or the butterflies will overheat. Figure 27-1. Catching a butterfly in the butterfly tower. BACKGROUND INFORMATION Metamorphosis is the term for the change that butterflies undergo during the course of their life cycle. Butterflies are examples of insects that go through complete metamorphosis, since their immature stage, the larval stage, is completely different in appearance and lifestyle than the adult stage. Once the larvae have grown to full size, they enter the pupal stage (as described in the Background Information for Activity 25), where dramatic changes take place. Inside the pupa the parts of the larva are being broken down as quickly as the adult parts 266 activity 27 Emerging Adults are being formed. The larval cells die and produce energy for the rapidly growing adult organs. While the larva is being taken apart, the contents of the pupa are largely liquid. The heart, trachea, and nervous system of the animal change very little, but all else is completely redesigned. The simple eyes are formed over into huge compound eyes, the muscular system is revamped for its new job of flying and walking with long, jointed legs, and the reproductive system matures to enable the adult to carry out its function of reproduction. After a set time, which differs for each species, the adult insect is ready to emerge. Sometimes the shape and color of the wings can be seen through the pupa shell shortly before this occurs. This is a sensitive and vulnerable time for the animal. First the pupa case splits behind the head and the insect frees its legs and antennae. After a rest, the animal crawls all the way out of the shell. If the pupa is encased in a cocoon, as in most moths, it must also free itself from the strands of the cocoon. Some insects do this with a special fluid that partially dissolves the silk of the cocoon, while others cut a special escape hatch into one end of the cocoon. When the adult first emerges, its wings are crumpled, soft, and wet. The insect pumps blood into its wings, gradually expanding them to their full extension, where they harden into usable wings. Often the insect will climb to a position where its wings hang downward to allow gravity to help with this process. If the insect s wings run into any problems and do not extend fully, they will harden in this bent position, leaving them unusable. It is likely that at least some of the butterflies the students are studying will run into difficulties while emerging. Most often, the difficulty is that the butterfly is unable to pull itself completely free of the chrysalis quickly enough, and ends up with wings that are not completely open before they harden.
Activity Sheet 27 Emerging Adults 1. What does a butterfly look like when it comes out of the chrysalis? Circle the picture. a. b. 1 2 Guiding the Activity If possible, have students observe one of the butterflies emerging from its chrysalis. Distribute a copy of Activity Sheet 27 to each student, and have students identify this process. Discuss their observations as a class. Ask, What does the butterfly look like when it first emerges from the chrysalis? 2. Write the names of the parts on this picture of the butterfly. Can you find all these parts on your live butterfly? proboscis head Ask, What does it do next? wing antenna body Additional Information Have students help you check the pupae regularly when the time is near (7 10 days after the pupae form). broward county hands-on science Quarter 3 267 eye It is wet and its wings are folded and crumpled. It crawls up on something and pumps its wings to their full size. After several hours the wings are full size and harden into shape. At this point the butterfly is able to fly.
Guiding the Activity Additional Information Figure 27-2. An emerging butterfly. Show the students the illustration of an emerging butterfly in the Butterflies and Moths book. (See also Figures 27-2 and 27-3.) Students may notice drops of red liquid near the emerging butterfly. Ask, What do you think the red drops are? Tell them that this red substance is not blood. (In any case, insect blood is not red!) It is a waste product discarded by the butterflies consisting of leftover coloring and tissues from the wing formation. Ask, How do you feel about seeing the butterflies emerge from the chrysalises? Ask, What other questions do you have about this? 268 activity 27 Emerging Adults Figure 27-3. A newly emerged butterfly expands its wings. Students can also examine the pictures on the poster. Students are likely to say they are blood, and may be concerned because their butterflies are bleeding. The red substance is called maconium. Students may be surprised that such a transformation could really take place, even though they have probably heard about it before. They may be full of questions about the process. Make a list of their questions for future study and investigation.
3 Guiding the Activity Project the Adult Butterfly transparency and point out the body parts of the adult. Include the head, body, compound eyes, antennae, proboscis, segments, fore-wings, and hindwings. (See also Figure 27-4.) Additional Information The front pair of legs are difficult to see because they are dwarfed, and the butterfly holds them folded against the front of its body. 4 Distribute a container with a live butterfly, and four magnifiers to each team of four. Have students observe the butterflies and look for the various body parts described on the transparency (as well as the legs). Allow students time to label the butterfly on the activity sheet. Ask, How are the adults different from the larvae? Ask, Are there any ways in which the adults are the same as the larvae? 5 Write metamorphosis on the board. Explain that metamorphosis means a change, or transformation. Explain that the process that a butterfly goes through when it changes from a larva to a pupa to an adult is called metamorphosis, because it involves such a complete change in the animal s appearance and behavior at each stage. Figure 27-4. The Painted Lady butterfly. Leave the transparency projected for easy reference while students work. The most obvious differences are that they have wings, longer legs, and longer antennae. Other differences include their color, body shape, and eyes. Both life stages have segmented bodies with fuzz, or hairs, on them. Students may be aware of other animals that go through metamorphosis, such as many insects, or frogs and toads. broward county hands-on science Quarter 3 269
Guiding the Activity Release the butterflies back into the butterfly tower. Wash and dry the empty containers and return them to the kit, along with the magnifiers, the dropper of sugar water, the Adult Butterfly transparency, and the Butterflies and Moths book. Additional Information Remove the lids from the containers after you have placed them inside the tower, and gently shake out the butterflies. R EINFORCEMENT Observe some of the other larvae that the students or you have collected as they emerge from their pupae. Discuss how the different species are similar or different in their metamorphosis. Emphasize that the pupa is not a resting stage in an insect s life cycle. Although we cannot see much happening, huge changes in the insect s body are taking place inside the pupa case. The larva s body breaks down until it becomes almost a liquid. Then new body tissue is built up and new body parts are formed. 270 activity 27 Emerging Adults SCIENCE JOURNALS Have students place their completed activity sheets in their science journals. C LEANUP Collect the magnifiers and return to the kit. Wash and dry the empty containers and return them to the kit as well.
Connections Science Challenge Science Extension Ask students whether they know of any other animals besides insects that undergo major changes in the structure of their bodies as they develop into adults. Students will probably mention that frogs develop from tadpoles. As a class, find out what other types of animals undergo such changes. (toads, salamanders, eels, sea squirts, starfish) Suggest that students pick an animal and present an oral report about it to the class. Suggest that students accompany their reports with photographs or drawings of the animals. Set up an aquarium with frog eggs or young tadpoles to give students an opportunity to observe tadpole development directly. (Frog eggs can be obtained from a biological supply house. If the season is appropriate, you or students could collect eggs or tadpoles outdoors.) Make sure the aquarium provides both ample water depth for eggs and young tadpoles and at least one above-water surface (a log or a stone) for older tadpoles and young-adult frogs. Let students help you collect materials, set up the aquarium, and research the food needs of tadpoles and frogs. Post a calendar near the aquarium so that students can record the physical changes that occur in the tadpoles: development of the hind legs first and then the front legs; widening of the mouth; disappearance of the gills and development of nostrils (indicating the internal development of lungs); and gradual shortening (resorption) of the tail. Also have students note changes in the animals behavior, such as spending more time at the water surface, then venturing out of the water. Tell students that the length of each stage of the life cycle, and of the entire life cycle, is different for different kinds of frogs. Now that students have observed the complete life cycle of the butterfly, help them complete a two-column table that you have prepared for comparing and contrasting the characteristics of the larva and the adult. For example, both the larva and butterfly have three pairs of legs, one pair of antennae, one pair of mandibles, and simple eyes that can detect light. Differences include the large, compound eyes and two pairs of wings in the adult, as well as most obviously their vastly different overall appearance. Accept other likenesses and differences that students suggest as long as they are based on observable evidence. Science and Math As a class, calculate the length (in days) of each stage in the life cycle from larva to adult butterfly. Help students plot these data on a time line with the days numbered and the life stages labeled. Science and Language Arts As a class, find out where the word metamorphosis comes from. (from the Greek meta, meaning involving change, and morphe, meaning form ) Ask students to summarize the changes in form that they have observed in the life cycle of butterflies. broward county hands-on science Quarter 3 271
272 activity 27 Emerging Adults