Hatching Science: 21 Days of Discovery

Summary

This educational video script from Utah Agriculture in the Classroom explores the fascinating 21-day journey of a chick's development from egg to hatchling. It details the formation of the egg, the embryo's growth, and the chick's preparation for life outside the shell. Highlighting the vital components of the egg and the chick's organ development, it explains the importance of a warm, moist environment and turning the eggs for proper growth. The script culminates in the chick's hatching process, emphasizing the instinctual behaviors that guide the newborn to quickly adapt to its surroundings.

Takeaways

• 🐣 The process of a chick's development from egg to hatching takes 21 days, starting with the formation of an embryo within a yolk.
• 🥚 The egg's shell is the last part to form, after the yolk, albumin, and germinal disk are in place, providing protection and structure.
• 💨 The eggshell has thousands of tiny pores that allow oxygen to enter, essential for the chick's development.
• 🥚 The yolk supplies nutrients, the albumin offers a protective cushion and additional protein, and the germinal disk is the site of the chick embryo.
• 🌡 Eggs require a moist, warm environment and must be turned regularly to ensure proper chick development.
• 🐥 By the end of the first day, the chick's embryo is about 3 millimeters long, and specialized cells are forming various organ systems.
• ❤️ On day 2, the chick's heart begins to form and beat, circulating blood through vessels that connect to the yolk.
• 🦴 By day 5, the chick's reproductive organs start to develop, and leg bones begin to form but are not yet hardened.
• 👀 On day 6, the chick's beak becomes visible, and its intestine starts to loop to fit inside its body, while the first feather buds appear on day 7.
• 🦆 By day 9, the chick develops eyelids and kneecaps, and by day 10, it starts to exercise more as its more refined features like claws and comb develop.
• 🕊️ On day 21, the chick hatches, using an egg tooth to break out of the shell, and within hours, it dries out, begins to walk, and starts to explore its environment.

Q & A

What is the main focus of the 'Utah Agriculture in the Classroom's hatching science movie'?

The main focus is the 21-day process of a chicken egg hatching into a chick, exploring the question of which came first, the chicken or the egg.

What is the initial component of an egg that forms inside a mother hen?

The initial component of an egg that forms inside a mother hen is the yolk, which may have an embryo attached if the egg is fertile.

What is the role of the albumin in an egg?

The albumin, also known as the egg white, serves as a protective cushion for the developing chick and provides protein as the chick grows rapidly.

What is the function of the eggshell's pores?

The pores in the eggshell allow oxygen to enter, which is essential for the chick's development and respiration.

What is the germinal disk and its significance in egg development?

The germinal disk is the area where the chick embryo is located. It starts as a single cell and, under the right conditions, grows into a full-sized chicken.

What is the purpose of the air cell found at the base of the egg?

The air cell is a pocket of air that the chick uses when it is ready to take its first breath outside the shell.

What is the role of the chalaza in the egg?

The chalaza serves to anchor the yolk in place, preventing the embryo from getting damaged and ensuring it stays in an optimal environment for temperature, moisture, and nutrient access.

What are the two membranes found inside the egg, and what is their function?

The two membranes inside the egg act like a protective barrier, allowing oxygen in and keeping bacteria out. They also help maintain moisture inside the egg and let waste gases like carbon dioxide out.

How do humans ensure the proper development of chick embryos when they cannot sit on the eggs like mother hens?

Humans use incubators to provide the necessary warmth and humidity, and they turn the eggs at least three times a day to ensure the chick develops correctly.

At what stage of development do the chick's reproductive organs begin to form?

The chick's reproductive organs begin to form on day 5 of the development process.

What happens on the 21st day that signifies the chick is ready to hatch?

On the 21st day, the chick's neck begins to spasm automatically, which will cause it to peck its way out of the egg, signaling that it is ready to hatch.

Outlines

00:00

🐣 The Formation of a Chick's Egg

This paragraph introduces the process of egg formation in a hen, detailing the development of a fertilized egg into a chick. It explains the initial formation of the yolk, the attachment of the embryo, and the subsequent coating with albumin and the hard shell. The paragraph also highlights the egg's internal components, including the shell's protective role, the yolk's nutritional supply, the albumin's cushioning and protein provision, the germinal disk as the site of embryo development, the air cell for the chick's first breath, the chalaza's role in stabilizing the yolk, and the membranes that regulate the internal environment. The importance of the external environment for egg incubation, including temperature, humidity, and turning, is also discussed, with a comparison between natural hatching by mother hens and human-assisted incubation methods.

05:02

💓 The Intricate Development of a Chick's Embryo

This section delves into the intricate developmental stages of a chick's embryo within the egg. It begins with the formation of specialized cells that will later become vital organs, the emergence of the heart and ears, and the initiation of blood circulation. The paragraph emphasizes the simultaneous development of various body systems, including the brain, eyes, and digestive system. As the days progress, the chick's body parts, such as the head, tail, wings, and legs, become more defined, and organs start to form tissues. The paragraph also describes the chick's preparation for hatching, including the formation of reproductive organs, leg bones, beak, feathers, and the egg tooth, which will be used for breaking out of the shell. The importance of exercise for the developing chick and the gradual consumption of the yolk for nutrients are highlighted, leading up to the chick's readiness for hatching.

10:02

🐥 The Hatching Process and the Chick's First Days

The final paragraph describes the dramatic and final stages of a chick's development and the hatching process. It details the chick's preparation for hatching by turning its beak towards the air cell and the physical changes that occur as the chick's body occupies the entire egg space. The paragraph narrates the chick's first breath, the use of its egg tooth to break the shell, and the subsequent rest and preparation for the exit. It also discusses the chick's emergence from the egg, its initial moments of rest, and the gradual drying, rising, and movement as it acclimates to its new environment. The paragraph concludes with insights into the chick's instinctual behaviors for survival, such as eating, drinking, and seeking warmth, and provides information on resources for further education on hatching chicks.

Keywords

💡Egg

The egg is a biological vessel for the development of an embryo, in this case, a chick. It is the central theme of the video, illustrating the process from egg to chick. The script describes the formation of the egg, its components, and the chick's development within it, emphasizing the egg's role in providing protection, nutrients, and the necessary environment for growth.

💡Embryo

An embryo is the early developmental stage of a multicellular organism. In the video, the embryo is the initial form of the chick, starting as a single cell that will grow into a full-sized chicken. The script explains how the embryo is attached to the yolk and how it develops specialized cells and organs over the 21 days within the egg.

💡Yolk

The yolk is a nutrient-rich part of the egg that provides sustenance for the developing embryo. The script describes the yolk as the source of nutrients for the chick, highlighting its importance in the chick's growth and development.

💡Albumin

Albumin, also known as egg white, is a protein substance that surrounds the yolk and provides a protective cushion for the developing embryo. The script mentions albumin as a crucial component that not only safeguards the chick but also supplies protein during its rapid growth phase.

💡Shell

The shell of an egg is a hard, protective outer layer that shields the developing chick. The script details the shell's formation as the final step in egg production and its role in protecting the chick while allowing for the exchange of gases through its pores.

💡Germinal Disk

The germinal disk is a small spot on the yolk where the embryo is located and from which it develops. The script identifies the germinal disk as the starting point of the chick's development, beginning as a single cell and growing into a complete organism.

💡Chalaza

Chalaza refers to the twin spiral cords that anchor the yolk within the egg, preventing it from moving too much and potentially harming the embryo. The script explains the importance of chalaza in maintaining the yolk's position and ensuring a stable environment for the embryo.

💡Membrane

Membranes within the egg serve as selective barriers, allowing for the passage of essential substances like oxygen while keeping out harmful entities such as bacteria. The script describes two such membranes that regulate the internal environment of the egg, ensuring the chick's healthy development.

💡Incubation

Incubation is the process of maintaining the optimal temperature and humidity for the development of an embryo. The script discusses how mother hens naturally incubate their eggs and how humans use incubators to replicate this process, emphasizing the necessity of turning the eggs to ensure proper chick development.

💡Egg Tooth

An egg tooth is a small, temporary protuberance on the chick's beak that is used to break the shell during hatching. The script mentions the formation of the egg tooth and its role in the chick's emergence from the egg.

💡Hatching

Hatching is the process by which a chick breaks out of its eggshell to enter the outside world. The script describes the final stages of development leading up to hatching, the chick's first breath, and its struggle to break free from the egg, culminating in its emergence and adaptation to the external environment.

Highlights

The egg formation process begins inside the mother hen's body with the development of a yolk and potentially a fertilized embryo.

Egg white, or albumin, is added to the yolk as the egg passes through the hen's tube.

The egg's hard shell is the final layer applied just before it is laid, serving as a protective covering.

The eggshell has thousands of pores allowing oxygen to reach the developing embryo.

The yolk supplies essential nutrients for the chick's growth, while the albumin offers a protective cushion and additional protein.

The germinal disk contains the chick embryo, which starts as a single cell and grows into a full-sized chicken given the right conditions.

An air cell at the egg's base is crucial for the chick's first breath.

Chalaza anchors the yolk, protecting the embryo from damage and maintaining optimal conditions for development.

Two membranes inside the egg regulate the passage of substances, ensuring a healthy environment for the embryo.

Eggs require a moist, warm environment and regular turning for proper chick development.

Incubators are used by humans to provide the necessary warmth, humidity, and turning for egg incubation.

The embryo begins forming specialized cells into complex organ systems within the first few hours.

By day 2, the chick's heart begins to form and beat, circulating blood through developing organs.

Organ systems develop concurrently, challenging the notion of sequential development.

By day 3, the chick's head, tail, and wing and leg buds become visible, with tissues forming into organs.

On day 5, reproductive organs begin to form, indicating the start of the next life cycle.

Feather buds appear by day 7, marking the beginning of the chick's unique features.

On day 21, the chick hatches, using an egg tooth to break out of the shell.

After hatching, chicks are able to walk and rely on their instincts for survival, needing only basic care from humans.

Transcripts

Welcome to Utah Agriculture in the Classroom's

hatching science movie, a full 21 days of discovery from egg

to chick.

Which came first, the chicken or the egg?

Today, we're going to start with the chicken.

This is a mother hen.

Inside her body, an egg begins to form.

At first, it's mostly yolk.

And if the egg is a fertile one, an embryo or baby chicken

will be attached to the yolk.

As it passes through this tube, it

is coated with albumin, also known as the white of the egg.

Right before it's laid, it stops in a little compartment

where it's coated with a hard covering.

The shell actually comes last.

This is a continuous process.

As one egg is leaving the hen's body,

the next is already well underway.

The egg contains everything a developing chick or embryo

needs to grow into a baby chick that can

survive in the outside world.

The shell is the heart covering that protects the chick,

but it also has thousands of tiny holes called

pores that let oxygen in so that the chick can get new air.

The yolk supplies the chick with nutrients.

The albumin or egg white provides a safe cushion

for the chick in case the egg is bumped

and also supplies protein when the chick begins

to grow very rapidly.

The germinal disk is where you can find the chick embryo.

It starts out as one tiny cell, but given

the right circumstances, it will grow into a full-sized chicken.

There air cell is a pocket of air at the base of the egg that

will be used by the chick when it is

ready to take its first breath.

Chalaza, may be a difficult word to say,

but it serves an important role by anchoring the yolk in place.

This keeps the embryo from getting beat up

and bruised as the egg is turned.

And also keeps it in place where temperature, moisture,

and nutrient access are perfect.

Lastly, two membranes can be found just inside the shell.

These membranes are like the police of the egg.

They make sure that good things like oxygen get in

and bad things like bacteria stay out.

They also ensure that moisture stays inside the egg

but waste gases like carbon dioxide can get out.

Just as important as what's inside the egg

is the environment outside the egg.

Eggs need a moist, warm environment

in which to survive.

They must also be turned to make sure that the chick develops

correctly.

Mother hens will sit on their eggs

to keep them toasty and humid, and they know instinctually

when to turn them.

We humans don't have the time or ability to sit on eggs,

instead we use incubators--

there are many different types of these--

to provide the warmth and humidity.

And we must remember to turn the eggs at least three times

a day to keep the baby chicks inside healthy and happy.

Even as early as the first few hours the embryo

begins to form specialized cells that will become complex organ

systems later on muscle cells, nerve

cells, and digestive system cells are forming,

but none of them will work yet.

Blood vessels begin to form but no blood

can pass through the vessels yet.

Even the eyes are starting to form.

The embryo will be about 3 millimeters long

by the end of the first day.

Things happen quickly on day 2.

At 25 hours old, the chick's heart begins to form.

At 33 hours, the ears begin to form.

And at 42 hours, the heart starts to beat and send blood

through the vessels that connect the yolk, the source

of the chick's nutrients, to the embryo's developing organs.

Can you see the heart beating in this video?

At the same time, other specialized cells

continue to divide and grow.

Note that the chick develops each of its body systems

at the same time.

You might think that blood vessels develop first

then the blood that will pass through them forms.

But this is untrue.

Instead, both of these things form at the same time.

And when both are ready, they start to work together.

Different organ systems develop at the same time too.

For example, even though all organs

rely on the brain for instructions, the brain, eyes,

digestive system, and all other organs

form at the same time instead of waiting for one to finish

before the other one starts.

When they are already, they will work together.

By day 3, the head and tail can be

seen as well as the buds that will become wings and legs.

The specialized cells begin to form

tissues which will eventually form organs

like the tongue, liver, kidneys, and lungs.

To supply all of these cells with the nutrients

they need to keep growing, more blood and blood vessels form.

On day 4, the toes begin to form.

At this point, most of the chick's body parts are present

but most of its organs are still too simple to function.

The chick is so tiny that its heart is only

a fraction of an inch from its eye.

It still has a lot of growing to do.

The chick's tiny body has separated from the yolk.

The embryo still relies upon the yolk for nutrients.

But now, it also rests upon the yolk

as if it were a comfy pillow.

In this time lapse video of a chick's development

from day 2 to day 3, you can see the heart

begin to beat regularly as the chick's small body lengthens

and widens out.

On day 5, the chick is already starting

to form the next link in the life cycle chain

as its reproductive organs begin to form.

This means that before a chick is even hatched from its egg,

it is getting ready to make more chicks later on.

On day 5, the leg bones begin to form

but it will still be a few days before any of the chick's bones

harden.

On day 6, the beak becomes visible

and the chick is able to bend its wing at the elbow.

Its intestine, which before was just a simple tube,

is getting so long that it must loop around in order

to fit inside the chick's body.

You may be asking yourself, well,

when will this silly chick get its feathers?

Day 7 is the day.

Today, the first feather buds begin to appear along

its tail and thigh.

The eye is developing rapidly in this stage.

And today, the chick will be able to bend

its knees for the first time.

On day 8, more feather buds appear and an egg tooth forms.

On day 21, this egg tooth will be

the tool this chick uses to break out of its shell.

In the next few days the check will start moving around a lot.

It needs to exercise its new muscles as much as

possible while it can.

Pretty soon, the little chick will

be too big to move inside the egg at all.

On day 9, eyelids and kneecaps develop.

The yolk still has plenty of nutrients

left to help the chick until it hatches.

But the yolk is now noticeably smaller

than it was in the beginning.

On day 10, the chick moves even more and some of its more

refined features develop--

claws, comb, and flight feathers.

In the video, you can see that the chick is still exercising

by the end of day 11.

This exercise is good for its skeleton too,

and it will begin to use calcium from the shell

to harden its bones and beak.

On day 12, development continues and scales appear on the legs.

On day 13, the right and left collarbones

fused together to form the wishbone.

Here, you can see more movement inside the egg.

By day 14, the chick is starting to feel crowded.

Today or tomorrow, it will turn its head

toward the bottom of the egg and it will stay that direction

until it hatches simply because it's too big to turn around.

The skull has begun to harden, the chick

has used much of the yolk's energy and nutrients,

and by now, the yolk is noticeably smaller and even

difficult to distinguish from the rest of the developing

chick.

On day 15, the scales, claws, and beak

become firm as the chick continues to develop

all of its other parts.

By day 16, everything is in place.

Now, it's just a matter of time before the chick's body

is developed and strong enough to survive outside the egg.

Day 17 brings an exciting development.

The chick turns its beak toward the air cell

to get ready to take its first breath.

Since the chick can't move inside the egg,

it turns its head by developing a double bend in its neck.

In other words, its neck makes a full loop.

First toward the skinny side of the egg,

then rounding back toward the blunt side of the egg where

the air cell is.

By day 18, the chick is almost ready.

This X-ray video of an 18-day chick

shows how the skeleton is nearing full development.

On day 19, the chick breaks through the membrane on the air

cell and takes its first breath.

The lungs inflate and begin to function.

The last of the yolk sac enters the chick's body

where any remaining yolk will be used to help the chick survive

after it hatches.

On day 20, the chick relies completely

on its lungs for respiration and its body takes up all the space

in the egg.

It's finally day 21 and the chick's neck

begins to spasm automatically.

This is what will cause the chick to peck its way out.

It's time for the egg-citement.

You will probably be able to hear

the chick tapping long before the chick's beak pops through.

Once it does, the exhausted chick

will take a breather, literally breathing the outside air

to get used to the new environment

and to prepare for the hard work ahead.

This break will take three to eight hours.

Once the chick has rested, it begins

to turn slowly inside the egg, tapping the shell

open as it goes, and effectively cutting off the top of the egg.

Once it's made it about 3/4 of the way around,

this may take up to five hours, things start to go much faster.

The chick begins to push and struggle

against the top of the egg, trying

to break out in a process that should take only

about 40 minutes.

Then suddenly, it's the moment you've been waiting for.

The chick emerges, wet and panting for air.

It will lie still for a while, but don't worry,

it's just resting.

After all, breaking out of an egg shell is hard work.

Soon enough, it will begin to rise to its feet.

It may seem unsure of itself at first

while it figures out its muscle coordination.

But within hours, it will be all the way,

dried out, and peeping and hopping

around under the Farrugia lights.

Unlike human babies, chicks emerge

with bodies that are able to walk within hours.

Chicks rely on their instincts to know when they need

to eat, drink, and find warmth.

All we humans need to do is provide them

with food, water, and heat, as well as some room to exercise

and the chicks will babysit themselves.

This has been a presentation by Utah Agriculture

in the Classroom.

For more resources and lesson plans on hatching chicks,

please visit us online at utah.edclassroom.org.