## UNSCRAMBLE THE MYSTERY: FROM EGG TO CHICKEN Grades 6-8

In this lesson and its extension opportunities, the students should have the opportunity to learn about the parts of an egg and its function in the development of the chicken. Students will perform various experiments in which they will note patterns and change in an egg due to the porosity and permeability of an egg. Additionally, students will perform an experiment in which they will observe the strength of an egg's shell.
Take A Look #5: Eggs
Students will be able to:
• identify the parts of an egg
• label a diagram of an egg
• state the basic function for each part of an egg
• observe the movement of liquid through pores of an eggshell
• analyze and compare the affect of vinegar, water, and corn syrup on an egg
• and estimate and compare the amount of air released from the air cell (air sack) of various eggs
Per individual:
• 1 egg diagram
Per group of 4 - 6 students:
• 1 raw egg and container
Per group of 4 - 6 students:
• When Will I Hatch Activity calendar of month(s) determined by the teacher
Eggshell Porosity Activity:
• 1 hard-boiled egg
• 1 hand lens
• 1 toothpick
• blue food coloring
• graph paper

Membrane Permeability, Activity One:
• 1 cup of water
• blue food coloring
• 1 rubbery egg (made by soaking an egg in vinegar for 24 - 48 hours)
Membrane Permeability, Activity Two:
• 2 rubbery eggs of comparable size and weight
• 1 tape measure
• 1 balance and weights
• 1 cup of corn syrup
• 1 cup of water graph paper
Filled With Air Activity: To one group, distribute a small egg, to the next group a medium egg, to another a large egg, and to the last group an extra large egg which has a pre-drilled hole completed by the teacher.
• 1 cup of water (per group)
• stop watch
• graph paper
The Strength of Shells Activity:
• 1 sheet of plastic wrap
• 1 newspaper
• 3 eggs
• 1 balance and weights
• several books of the same size and weight
• graph paper
The following words will be introduced during the viewing segment: germinal spot - the part of an egg from which a chicken will develop albumen - the white of an egg which acts as a cushion for the yolk - the round yellow mass which provides nutrients for the developing embryo air sack (cell) - the air space usually found at the large end of the egg shell membrane - two thin membranes next to the shell and surrounding the albumen and yolk; known as the inner and outer shell membranes; they are one of the egg's chief defenses against bacterial invasion shell - the hard outer surface of the egg made up largely of calcium carbonate; the shell has pores which allow the egg to lose carbon dioxide and moisture chalazae - the two whitish cords on opposite sides of the yolk which hold the yolk in the center of the albumen and serve as rotating axis to keep the germ cell on the top side of the yolk and next to the hen's body fertile - an egg that is fertilized; the capability of an egg to develop into a chick infertile - an egg that is not fertilized; will not hatch

Distribute a hand lens and a container with one cracked, raw egg per group. Students are to examine the egg and predict the function of each part.

The teacher will list the observations and predictions generated by the students on the board. Use the vocabulary presented by the students and adjust predictions as needed during the viewing segments.
The focus for viewing is a specific responsibility or task(s) students are responsible for during or after watching the video to focus and engage student viewing attention. Students will watch this video to learn how to correctly identify and label the parts of an egg. Prior to labeling a diagram of the egg, students will be asked to compare their predictions (listed on the board) with the actual name and function of each part of the egg. After each pause, the teacher should refer the students to their predictions and modify them as necessary. Additionally, students should use their raw egg to locate the parts as they are mentioned in the video segments. The initial segment explains the difference between a fertile and an infertile egg.

BEGIN the video Take a Look #5: Eggs as Kate and her friend are leaving the barn. The audio cue is " The hens sure are laying a lot of eggs. Why aren't there any chicks? Don't chicks come from eggs?"

PAUSE just prior to Kate's cracking the egg. The audio cue is "Here I'll show you!" Students will view the next segment to learn which part of the egg will develop into the chick. After Kate identifies the germinal spot, have students locate this spot on their raw egg.

Note to the teacher: If the germinal spot cannot be located, it may be necessary to turn over the yolk.

RESUME and PAUSE after the question "What's the yolk for?" Refer student attention to their prediction listed on the board. Watch this segment to verify or alter the information predicted for the function of the yolk.

RESUME and PAUSE after Kate explains "It's full of nutrients. That's why we eat it." Have students locate the white string-like objects found on the raw egg. Students are to listen to the next segment to determine their function.

Note to the teacher: The video segment does not name these cords. They are called the chalazae. If desired, the teacher will need to introduce this term. RESUME and PAUSE after the audio cue "The yolk is also protected by the white part."

Students are to view the next segment to learn the function and the correct vocabulary term for the white portion of the egg. RESUME and PAUSE after the question "And what other thing helps protect the young chick?" Have students predict the answer to this question, then watch the next segment for verification.

RESUME and PAUSE after Kate explains that the chick uses the calcium in the shell for its bones. In the next video segment, Kate will poke a hole in the shell to demonstrate the release of air from the air cell of the egg. Students should make special note of which end of the egg contains the air cell. They will use this information in one of the post-viewing activities.

Note to the teacher: Prior to resuming the video, distribute the diagram of the egg. Students will use the information in the video to correctly label this diagram. The first item to be identified is the germinal spot. Have students locate this item on their diagram. Additionally, they should recall its function. Students should listen to confirm this information.

RESUME and PAUSE after the question "And the yolk?" Students should correctly label and define the germinal spot. Students should locate the yolk, then listen to the next video segment for verification.

RESUME and PAUSE after the statement" . . . then there's the albumen." Have students label and define the yolk. Students should locate the albumen, then listen to the next video segment for verification.

RESUME and PAUSE after the statement " . . . then we have the air sack." Students should label and define the albumen. Students should locate the air sack, then listen to the next video segment for verification.

Note to the teacher: Students will need to locate and label any additional parts, such as the chalazae, which was discussed earlier, but not presented during the interactive labeling section.

RESUME and PAUSE after the question mark is displayed. During the remaining portion of the video, students will be asked to use their diagrams to help them review the egg parts. The students will be asked to come to the television and locate the albumen, yolk, and germinal spot.

Turn off the sound. Ask for a volunteer to locate the albumen. SLOW ADVANCE the video as the student approaches the screen to locate the albumen. PAUSE the video after the term "albumen" and the arrow locating it are displayed on the scene. Ask another volunteer to define its function.

Ask for another volunteer to locate the yolk. RESUME and PAUSE after the term and arrow for the yolk are presented on the screen.

Ask for another volunteer to locate the germinal spot. RESUMEand PAUSE after the term and arrow for the germinal spot are presented on the screen.

Note to the teacher: The location of any additional parts must be determined by the teacher.

FAST FORWARD and RESUME as the chick is seen hatching from the egg. Students are to determine the number of days required for a chick to develop and hatch. Students will be required to utilize this number during a post-viewing activity; therefore, they should record this number for reference (21 days). PAUSE after the chick has dried. During the next segment, the strength of eggs is demonstrated. The students will recreate this activity and, therefore, need to listen for the procedure. RESUME and PAUSE after the verbal cue "Did you expect they'd hold so many?" Review the procedure for this activity. Display a rubbery egg. The students should listen for the procedure for making rubbery eggs. RESUME and STOP the video after the verbal cue "The acid in the vinegar has taken the calcium out of the egg, so it is soft and rubbery."
Students will use information presented in the viewing segments in the following activities:

When Will I Hatch? This is a problem-solving activity which builds upon their knowledge that a chick requires 21 days to develop and hatch. Provide the students with a calendar (especially challenging would be one in which holidays or vacation times must be considered). Have students calculate the day in which incubation should begin. Remind the students that the hatching date must occur during the school week otherwise this moment could not be observed. Note to the teacher: In most cases, incubation should begin on a Tuesday or a Wednesday.

Eggshell Porosity Remind the students that air and water will pass through the air hole in the shell of the egg to the embryo. Distribute the hard-boiled eggs and hand lenses. Have the students observe the eggshell to locate the pores. To make the pores more visible, use the toothpick to place a small dot of blue food coloring on the eggshell. Let the egg dry for at least one hour, longer if possible. Toward the end of class time, observe the egg and note any changes. Remove the shell and observe the blue area on the cooked egg white. Explain that the food coloring went through the pores in the eggshell, just like the air and water go through them to the embryo.

Membrane Permeability, Activity One To demonstrate membrane permeability, place several drops of blue food coloring into a cup of water. The water should be a dark blue color. Place a rubbery egg into the blue water. Although these softened eggs can withstand a good amount of handling, caution the students to handle them gently so as to prevent rupturing the egg. The movement of the water into the egg will become apparent when the egg turns blue.

Membrane Permeability, Activity Two Select two comparable eggs. Using a balance, carefully weigh and measure the diameter of two eggs. Place one in a cup of water and the other in a cup of corn syrup. Keep the eggs in each substance for at least 45 minutes. At fifteen-minute intervals, remove and blot each egg, then carefully weigh and measure the eggs. Chart and graph the findings. Compare the results.

Note to the teacher: Soaking the egg in the vinegar to remove the shell leaves the semipermeable membrane. The permeability activities demonstrate the process of osmosis. Osmosis is the flow of fluid through a semipermeable membrane separating two solutions, which permits the passage of the solvent but not the dissolved substance. A liquid will flow from a weaker to a stronger solution, thereby equalizing the concentrations of solutions.

In these activities, the size of the egg will change due to the process of osmosis. As a result of the water diffusing through the membrane into the egg, an egg placed in the water will become larger and heavier. As the water inside the egg moves from the egg into the corn syrup, the egg placed in the corn syrup will become smaller and lighter.

Filled With Air Select a raw egg. The teacher should carefully drill a small hole in the larger end of the egg (the location of the air sack), place it in a cup of water, and time the interval it takes to release the air inside the air sack. The students should utilize this information to estimate the air release time interval of eggs of varying sizes. The teacher should drill a hole in the eggs which will be utilized by the student groups. The students should chart and graph their information. After completing this activity, students should compare results to determine if there is a relationship between the size of the egg and the time interval for the air that is released from the air sack.

The Strength of Shells Students will recreate the activity presented in the video. Distribute three raw eggs, newspaper, and a sheet of plastic wrap per group of students. Have students predict the number of ounces the eggs will be able to support before breakage occurs. Using books of equal weight, carefully place books on top of the three eggs. Record and chart the results. Select one group of students to record the results utilizing small eggs, while other groups record the results using medium, large, and extra-large eggs. Compare the results to determine if there is a relationship between the size of the egg and the number of ounces it can support before breakage occurs.
Write to an egg-producing company to learn how eggs are graded, packed, and shipped to prevent breakage.

Invite a local egg producer to the classroom to discuss the care of chickens and their production rates.

Write to the Agriculture Education Field Advisor for information about local egg producers, egg production, and the different breeds of chickens. Write to Tyson Farms to learn how long it takes to get the chicken from an egg to a poultry meat item. Ask them to explain their environmental plan for the safe disposal of refuse.

Write to local restaurants to determine and compare the number of eggs purchased and used in a week.
Math and Science: Have students design a container to protect an egg from breakage when dropped from a predetermined height.

Math: Have students record their daily egg consumption for a week. Then chart the daily egg consumption rate of the class to determine the average number eaten per day. The students could then compare their personal rate to the class average.

Math: Research and chart the egg size and/or incubation period of different birds.

Math: Calculate the cost per egg of the various egg sizes. Decide which is the better buy.

Language Arts: Have students pretend they are a chick preparing to hatch. Have them write about the hatching experience.

Language Arts: Have students submit their favorite egg recipe and construct a class egg recipe book.

Language Arts and Science: Have students write and illustrate a book about the chicken life cycle.

Social Studies: Have students view Reading Rainbow #809: Rechenka's Eggs to learn about a traditional Russian method of decorating eggs.

Art: Use crayons and black tempera paint to create crayon resistant egg designs like those seen in Rechenkas's Eggs.

Art: Construct papermaché egg boxes.

Art: Use egg cartons to construct imaginary creatures.

Science: Have students view Reading Rainbow #408: Chickens Aren't the Only Ones to learn about other animals that lay eggs.

Science: Incubate some chicken eggs. A good source of materials and additional information on how to incubate eggs can be found in "Agriscience Kit: #AK-01 Eggciting Experiments - Chick Incubation and Embryology." For more information, write to: Vocational Agriculture Service, University of Illinois, 1401 S. Maryland Drive, Urbana, Illinois 61801 or call (217) 333-3871.