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What's In An Egg?

Welcome to NSTA's Daily Do Teachers and families across the country are facing a new reality of providing opportunities for students to do science through distance and home learning. The Daily Do is one of the ways NSTA is supporting teachers and families with this endeavor. Each weekday, NSTA will share a sensemaking task teachers and families can use to engage their students in authentic, relevant science learning. We encourage families to make time for family science learning (science is a social process!) and are dedicated to helping students and their families find balance between learning science and the day-to-day responsibilities they have to stay healthy and safe.

What is Sensemaking? Sensemaking is actively trying to figure out how the world works (science) or how to design solutions to problems (engineering). Students do science and engineering through the science and engineering practices. Engaging in these practices necessitates students be part of a learning community to be able to share ideas, evaluate competing ideas, give and receive critique, and reach consensus. Whether this community of learners is made up of classmates or family members, students and adults build and refine science and engineering knowledge together.

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Materials

Items: Pen/Pencil, Paper, Eggs, Flashlight, Paper Plate, Cup, 2 Toothpicks, Plastic Spoon Google Slide: What’s in an Egg Presentation Video: YouTube – Are Miss Pauletta’s Eggs Fertilized? Handout: Student Reference – Egg Dissection Handout: Exploratorium – Anatomy of an Egg Handout: Exploratorium – The Science of Cooking Eggs Optional Handout: Science and Engineering Practices – Developed by NSTA using information from Appendix F of the Next Generation Science Standards Collection of Resources: Direct links to all videos, articles, handout materials, and other resources – https://bit.ly/DD-03-25-2020

Introduction Today's task explores something many students and families are familiar with - eggs! This task, What's in an Egg?, engages students in science and engineering practices to figure out why some eggs produce chickens (or other living things) and some do not. This task has been modified from its original design in order to be used by students, parents, and teachers in distance and home learning. While students could complete this task independently, we encourage students to work virtually with peers or in the home with family members. Before you begin the task, you may want to access the accompanying What's in an Egg Google slide presentation.

Presentation of Phenomena (What am I exploring today?) Guidance: Students will be introduced to the phenomenon - some eggs produce chickens and some do not - through the video. The goal is to get students thinking about eggs and wondering what makes one egg different from another. Presenting a phenomenon and asking students to generate questions about it creates a need to figure out the answer to those questions. This is authentic engagement and a powerful learning process (unlike "learning about" the difference between fertilized and unfertilized eggs and being asked to recall the information later).

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Presenting the Phenomenon: Have students watch the video clip (Slide 3). Ask them to think about the idea introduced in the video clip (Slide 3). "What is the difference between the egg we might eat and one that produces a chicken?' and have them write any questions they have down on a sheet of paper. ALL student questions are okay at this point. Our goal is to motivate curiosity and not distinguish between "good questions" and "bad questions" or "right questions" and "wrong questions". Common questions will arise for most students, which is what this task builds upon. Although some students may know that fertilized eggs can grow into chickens and unfertilized eggs are used as food, prompt them to think about other questions they might have about eggs. Suggested Prompts:

What questions do you have about how that happens? What questions do you have about the different parts of the egg? What questions do you have about other kinds of animal eggs?

Investigative Questions (What questions do I have about what I just saw?) Investigative questions are common questions kids may ask after they are introduced to the phenomena. Although questions may vary, many students are curious about why some produce chicks (or some other animal) and others do not. Guidance: It is important to allow time for thinking. Many students have ideas and questions but need time to formulate their idea or question into words. Some students may also benefit from writing things down first before they share. As adults we may be tempted to give them questions we feel might be important to explore, however we need to refrain from this and allow our students to practice asking their own questions. Common Questions: (Slide 4)

Can we eat all types of eggs? Do some chickens make eggs for the store that we eat and different chickens lay eggs

that make chicks? What is the difference between an egg that makes a chicken and one that we eat? How do we tell the difference?

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After all the questions have been asked, we want to prompt our students to express their own ideas of how to figure out the answers to their questions. Ask them, "What could we do to figure out some things about eggs?" Common Responses:

Break open some eggs to see what is inside Google some of our questions Get some eggs and see if they will hatch

Let's start by seeing if there is a way to figure out what is inside the egg without breaking it open. Ask, "Do you think there is a way to see inside an egg without breaking the shell?" Allow your students to express their ideas. Many students will say to x-ray them, so that is what we will do, kind of...

My Observations (What observations did I make that helps me answer my questions?) (Slide 5) If we were able to look inside an egg, what would you look for? What would you expect to see? Do you think we would see might see different things depending on the egg? Have students document what they will look for inside an egg and/or make predictions of what they might see. (Slide 6) Watch the video Are Miss Pauletta’s Eggs Fertilized? about the purpose of candling eggs. (Slide 7) Candling Eggs In The Fridge Now that we know that some eggs get fertilized and some don't you can take this time to explore one of the eggs you might have at home. Candling an egg at home can be done easily with a flashlight or you can also use the flashlight app on your phone. If you don't have any eggs to look at, you can use the picture below. As you investigate the egg with the light, what do you notice? Guidance: It is important that you let the students you are working with tell you what he/she notices and to not point out the things you notice as the adult. The goal here is to allow students to practice making careful observations. If your student is struggling to make observations use question prompts to guide them instead of stating what you see.

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Suggested Question Prompts:

Do you notice anything different with the ends (rounded tips) of the egg? How would you describe the shell? Can you see what is inside the shell?

Possible students observations:

The egg glows. The light shines through the egg. The shell has little spots all over it, like the light shine through more. One of the end is a little darker than the other. The light goes through but I still can't see what is inside the shell.

We have made some really cool observations, now let's take a minute to think about all the things we have figured out about eggs and look at questions we still need to answer. We have figured out:

Fertilized eggs could hatch into chickens (or other animals). Unfertilized eggs do not hatch into chickens and these are the one we get in the store to

eat. We can kind of look into an egg to see if it is fertilized or not. If an egg is fertilized we can see a dark spot and blood vessels starting to form. If an egg is not fertilized the light glows through the egg and sometimes we can see the

air sac. Questions we still have:

What is inside the egg? What do the different parts of the egg do? How would a chick get food inside the egg? How many parts does an egg actually have?

To answer these questions we will do an investigation to see what we can figure out by looking at what is inside the shell.

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Investigation (Based on my observations, this is my plan for investigating my question(s)….) Before allowing students to crack open an egg to make observations, have them write down or draw a picture of what they think they might see inside the egg. Many students will know that the egg consist of the shell, yolk, and the 'clear part' or whites and some may also talk about the white stringy thing. Although many students can identify the major parts of the egg they do not know the other part or the function of the different structures. Have students investigate an egg, inside and out (Slide 8). Please remember to follow safety procedures as you would when handling food items. You can also find the procedure for the egg dissection investigation here. The procedure sheet may be printed or student can read a digital copy. Guidance: Have students really look at the different parts of both the shell and the inside of the egg. As students identify and document the different parts, it is not necessary that they know the names of all of the different structures. Have students use their own words to describe the structures they observe. The goal is to get kids to notice that the egg has many different structures. As students add structures to their chart have them make predictions about what those do (function) and also add their reasoning (why do they think those structures do the things they do). When students are finished with their egg investigation they can use the following website to get more information on the structures of the egg and their functions. Research The Anatomy of an Egg. Students will probably not have observed each of the structures shown, and there is no need to document all of them. However, student may want to revise their charts to represent the names of the structures they did identify and its function.

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Building Consensus Let's look back at the questions we had at the beginning of this task, for example:

Can we eat all types of eggs? Do some chickens make eggs for the store that we eat and different chickens lay eggs

that make chicks? What is the difference between an egg that makes a chicken and one that we eat? How do we tell the difference?

Through our observations and investigations, were we able to answer most or maybe all of the questions. Think about all of things you just figured out about eggs and document them on your paper. Guidance: It is important that you allow students to document what they have figured out in their own words. Allow them time to get all their new understandings written down and then have a short discussion about what they have figured out through participating in this task. During this discussion the students should be doing most of the talking and the adult is there to listen and prompt the student. We have figured out:

Fertilized eggs could hatch into chickens (or other animals) Unfertilized eggs do not hatch into chickens and these are the ones we get in the store

to eat. We can candle an egg to see if it is fertilized or not. If an egg is fertilized we can see a dark spot and blood vessels starting to form. If an egg is not fertilized the light glows through the egg and sometimes we can see the

air sac. There are many different parts to an egg, more than what we thought. The different parts of the egg all do different things. The shell of the egg has pores that let things in and out. The yolk of the egg is what grows into a chicken. ...other

Who knew there was so much to figure out about eggs, are there more things we could find out about eggs? If you want to know more about the storyline this task was taken from please see the link in the Acknowledgement section.

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Note: If you want to learn more about how to get students talking, visit STEM Teaching Tool 48, How can teachers guide classroom conversations to support students' learning?

Home Connections Eggs are something many students are familiar with but know little about. Parents/Guardians can expand on the learning in this task in many ways at home, including:

Cooking eggs Cooking with eggs - why do we use eggs when we bake? Looking at the nutritional label - What structure make up the protein? or the fat? Soaking an egg in vinegar to see what happens to the shell

Another resource you could explore is The Science of Cooking Eggs

NSTA Collection of Resources: NSTA has created a What's in an Egg? collection of resources to support teachers and families using this task. If you're an NSTA member, you can add this collection to your library by clicking ADD TO MY LIBRARY located near the top of the page (at right in the blue box).

Acknowledgement This Daily Do is inspired by and uses materials from the How Do Eggs Become Chickens or Other Living Things? storyline created by Next Gen Storylines. Next Gen Storylines is an open-source resource that can be used by parents and teachers to implement students driven learning.

Student Reference - Egg Dissection Procedure   

Procedure for Part 1:   1. Make a t-chart like the one below in your science notebook on the very next blank  

page. Be sure to number the page and title it, “Egg Dissection.”     

Structure of the Outside of the Egg    Structure of the Inside of the Egg  

   

 

 

2. Collect: an egg , paper plate , cup , 2 toothpicks , and a  

plastic spoon from your teacher.   

3. First, draw a sketch of the outside of your egg before cracking it open. Add this  sketch to the t-chart for the OUTSIDE of your egg. Label what you observe about the  outside of the egg.   

4. Carefully, record the mass of this egg (remember to zero your scale after placing the  cup on the scale or subtract the mass of the cup or plate it is on from your  measurements). Add this data to the t-chart for the OUTSIDE of your egg.  

5. Now, one person should GENTLY crack the egg over the dish, so that it is just above  the surface of it. Slowly empty the contents into the dish.  

6. Make observations of the structures found inside the egg in the table below. Be sure  to make close, detailed observations.  

7. Carefully, use the spoon to separate any parts of the egg that you think your group  should weigh. Record the mass of each part (remember to zero your scale after  placing the cup on the scale or subtract the mass of the cup or plate it is on from  your measurements). Add this data to the t-chart for the INSIDE of your egg.  

8. Use the toothpicks and/or spoon to carefully move parts around and make any last  observations of the inside of the egg. Add these observations of the inside of the egg  to your t-chart.  

9. Follow clean up instructions.  

 

Science of Eggs: Anatomy of an Egg | Exploratorium

https://www.exploratorium.edu/cooking/eggs/eggcomposition.html 1/2

SHELL Bumpy and grainy in texture, an eggshell is covered withas many as 17,000 tiny pores. Eggshell is made almostentirely of calcium carbonate (CaCO3) crystals. It is asemipermeable membrane, which means that air andmoisture can pass through its pores. The shell also has athin outermost coating called the bloom or cuticle thathelps keep out bacteria and dust.

INNER ANDOUTER

MEMBRANES

Lying between the eggshell and egg white, these twotransparent protein membranes provide efficient defenseagainst bacterial invasion. If you give these layers a tug,you’ll find they’re surprisingly strong. They’re made partlyof keratin, a protein that’s also in human hair.

AIR CELL An air space forms when the contents of the egg cool andcontract after the egg is laid. The air cell usually restsbetween the outer and inner membranes at the egg’s largerend, and it accounts for the crater you often see at the endof a hard-cooked egg. The air cell grows larger as an eggages.

ALBUMEN The egg white is known as the albumen, which comes fromalbus, the Latin word for “white.” Four alternating layers ofthick and thin albumen contain approximately 40 differentproteins, the main components of the egg white in additionto water.

The Exploratorium is more than a museum. Explore our online resources for learning at home.

Science of Eggs: Anatomy of an Egg | Exploratorium

https://www.exploratorium.edu/cooking/eggs/eggcomposition.html 2/2

CHALAZAE Opaque ropes of egg white, the chalazae hold the yolk inthe center of the egg. Like little anchors, they attach theyolk’s casing to the membrane lining the eggshell. Themore prominent they are, the fresher the egg.

VITELLINEMEMBRANE

The clear casing that encloses the yolk.

YOLK The yolk contains less water and more protein than thewhite, some fat, and most of the vitamins and minerals ofthe egg. These include iron, vitamin A, vitamin D,phosphorus, calcium, thiamine, and riboflavin. The yolk isalso a source of lecithin, an effective emulsifier. Yolk colorranges from just a hint of yellow to a magnificent deeporange, according to the feed and breed of the hen.

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6/19/2020 Science of Cooking: Seasoning | Exploratorium

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The Exploratorium is more than a museum. Explore our online resources for learning at home.

“It is not often in life we have the privilege of handling amasterpiece of ingenuity. But we do it without thinking when wecook one of nature’s most brilliant creations—the unassuming butextraordinary egg.”—Anne Gardiner and Sue Wilson, The Inquisitive Cook

Try Making a Naked Egg!

Did You Know?

Recipes andactivities to do witheggs.

Heat ’em, beat ’em, ormix ’em up: There arescientific processesat work when youcook with eggs.

Can you tell a hard-cooked egg from a rawegg—without cracking theshell? What's yoursecret?

Visit an organic eggfarm, and see thescience behind raisingthose eggs.

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