The Egg Story Notes Sheet
Name:
Date:
1. The __________________________ is formed by a reproductive system composed of an _____________________
and an _________________________________.
 An ________________________ looks like a cluster of ______________________ and may contain up to
4,000 small eggs or _________________ (singular ovum) which can develop into yolks.
 Each ovum is attached to the ovary by a thin membrane sac or ________________________.
 The ________________________ is a large, coiled tube located in the left side of the hen’s
abdomen. In this oviduct all parts of the __________________, except the ____________________, are
formed.
2. It is divided into 5 distinct regions:

1.

2.

3.

4.

5.
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3. Reproductive System: Consists of the _______________, the organ where the yolk develops and the
______________________ where the egg is completed.
 The ovary is attached to the hen’s _____________, about halfway between the neck and the tail.
 The _________________, a tubelike organ about ___________ inches long, is loosely attached to the
backbone between the ovary and the tail.
4. Most female animals have _____________ functioning ovaries, but the hen uses only one, the
__________________________.
 The right ovary and oviduct remain ___________________________.
 A female chick is born with a fully formed _____________________ containing several thousand tiny
__________________, or future yolks. The ova begin to develop, one at a time, when the
______________________ (a hen less than 1 year old) reaches sexual maturity. Each yolk is enclosed in
its own _______________ or follicle.
5. Egg Laying Process:
 The ________________________________, also known as the funnel, captures the ovulated yolk.
i. The infundibulum is where __________________________, if it occurred, would take place.
 After about _________________ minutes, the yolk passes along to the magnum where, in about 3
hours, the hen deposits the albumen around the yolk.
i. As the _________________________ is formed, the yolk rotates, twisting the albumenous fibers
to form the _________________________.
 Next, in about ________________ hours, the two shell membranes are formed and some water and
mineral are added in the _________________.
 The egg has now reached its full size and shape and passes along to the _________________________
(shell gland) where, after _____________________ hours, it acquires its shell, shell color and bloom.
 After a few minute pause in the _______________________, the uterus inverts through the vagina, the
cloaca (the junction of the digestive, _________________ and reproductive systems) and the vent to
release the egg outside the hen’s body.
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 Laying of the egg is known as ________________________.
6. The Rooster: The reproductive system of a male chicken, or _______________________, includes
__________________ that produce the sperm and seminal fluid necessary for reproduction.
 _________________ have full fertilizing ability for about _______________ days.
 After that, ability of sperm to _________________ an egg is ____________________.
7. The _______________________________ carries the seminal fluid and sperm cells to the cloaca.
 The _______________ is an enlarge part where the _________________________ joins the end of the
alimentary canal.
8. The _________________________is the food-carrying passage that begins at the ________________ and ends
at the vent.
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9. The _________________ is the organ in the wall of the cloaca that puts the sperm into the hen’s reproductive
tract.
10. Mating: When a rooster mates with a hen, he ____________________ her and stands on her back.
 He lowers his _____________________ (vent) and then hen inverts her own cloaca (vent) to meet with
his.
 There is no __________________________, but the sperm packet released by the male is ten into the
hen’s cloaca or vent.
 From there the sperm makes its way to the _________________________ where it awaits the release of
an __________________.
 Sperm can live in the infundibulum for more than _______________________.
11. Mating results in ______________________ of sperm into oviduct.
 Sperm is stored in the _________________________________.
12. When the yolk enters the infundibulum from the ovary, ______________ penetrates the ___________________
- tiny whitish spot on the yolk.
 This becomes the blastoderm when fertilized- _______________________.
13. The egg: At time laid – about ___________________degrees F.
 As it cools to room temperature contents ________________________ creating a vacuum.
 Air is drawn into the egg through the large __________________ at the broad end of the shell forming
the air cell.
14. Before the egg is laid:
 The egg is ______________________.
 The ___________________ divides and begins to grow. All cells are _________________.
 The cells ______________________ into groups of specialized _______________________.
15. When the egg is laid: ________________________ of dividing cells clustered in small white
_______________________.
 Cell groupings will become individual ______________________.
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16. When the laid egg cools, cell division ____________________.
 Cooling at this point does not ________________________________________.
 Allows hen to lay ____________________ eggs to hatch at the same time.
17. ______________________ and development resumes when ______________________ by the hen or incubator.
 Egg only needs warm, humid environment while embryo is maturing.
18. Physiological process within the egg: Egg contains all it needs for the embryo to _______________ and develop.
19. Perfect balance of _______________________ to transform from the egg to chick.
 _________________________ from shell used for skeletal development.
 _________________ taken up and ___________________________ released through shell pores.
 Oxygen is combined with nutrients in the ___________________ to provide ___________________
energy.
 By-product ____________________ is used to replace moisture lost through evaporation.
20. Shell:
 The egg’s outer covering, accounting for about ___________________ of its total weight, depending on
the egg size.
 The shell is the egg’s first line of ___________________ against bacterial contamination.
 The shell is largely composed of ____________________________ (about 94%) with small amounts of
magnesium carbonate, calcium phosphate and other organic matter, including protein.
 ______________________________ is greatly influenced by the minerals and vitamins in the
____________________________.
 If the diet is _______________________ in calcium the hen will produce a thin or soft-shelled egg or
possibly an egg with not a shell at all.
 Occasionally, an egg may be prematurely expelled from the _______________ due to injury or
excitement without a shell.
 The same amount of ____________________________ which covers a smaller egg must be stretched to
cover a large one, hence the shell is __________________ in a larger egg.
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 ____________________ thousand tiny pores are distributed over the shell surface, a greater number at
the large end.
 As the egg ______________, these tiny holes permit moisture and carbon dioxide to move out and air to
move in to form the _______________________.
21. Albumen: Also known as ____________________. Depending on the size of the egg, albumen accounts for most
of an egg’s liquid weight, about ___________________.
 The white contains more than half the egg’s total ___________________, a majority of the egg’s niacin,
riboflavin, magnesium, potassium and sodium, and none of the __________________.
 The white of a large egg contains about __________________________.
 Albumen color is opalescent and doesn’t appear white until an egg is beaten or _________________.
 The cloudy appearance comes from ____________________________.
 As eggs age, carbon dioxide escapes, so the albumen of older eggs are more ___________________
than that of fresher eggs.
 The albumen consists of ______________ alternating layers of thick and thin consistencies.
 From the yolk outward:
i.
ii.
iii.
iv.
 As an egg ages, the egg white tends to ________________ because its protein changes in character.
That’s why fresh eggs sit up ______________________ in the pan while older ones tend to spread out.
 When you beat egg albumen vigorously, it _____________________ and increases in volume
_____________________________.
22. Yolk: The yolk, or yellow portion, of an egg makes up about __________________ of the liquid weight of the
egg. It contains all of the _________________ in the egg and a little less than half of the protein
 The yolk of a large egg contains about ___________________________.
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 The yolk contains a higher proportion of the egg’s vitamins than the white, including vitamins B6 and
B12, folic acid, panthothenic acid and thiamin.
 All of the egg’s vitamins A, D, E and K are in the _________________. Egg yolks are one of the few foods
naturally containing ________________________.
 The yolk also contains more calcium, copper, iron, manganese, phosphorus, selenium and zinc than the
___________________.
23. ___________________________ eggs are often produced by ________________________ whose egg
production cycles are not yet completely synchronized.
 They’re often produced too, by hens which are old enough to produced
_____________________________________________.
 ________________________ is also a factor.
 It’s rare, but not unusual, for a young hen to produce an egg with
_____________________________________.
 In _________________________ eggs, the yolk is the site of embryo formation.
 Yolk _______________ is determined by nutrition of the hen.
 __________________________: occasionally found on an egg yolk.
i. These tiny spots do not indicate a __________________________.
ii. Instead, they are caused by the _______________________ of a blood vessel on the yolk
surface during the formation of the egg.
24. Air Cell: The air-filled packet between the _______________ and shell at the ________________ end of the egg.
 When an egg is newly laid, it is about ________________________ degrees and has either no air cell or
a very small one.
 As the egg cools, the liquid contents _______________________ more than the shell and the inner shell
membrane ___________________ from the outer shell membrane to from the ___________________.
 As the egg ages, ________________________________________________ leave through the pores of
the shell, air enters to replace them and the air cell becomes larger.
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25. Extraembryonic Blood System: The yolk sac surrounds the yolk and draws ________________ from it for the
embryo.
26. The ______________________ is a transparent sac filled with a colorless fluid in which the embryo
___________________ that protects it from shocks and prevents it from drying out.
27. ________________________ (the transport of oxygen from the outside air to the cells within tissues, and the
transport of carbon dioxide in the opposite direction) is made possible by the ________________________.
 As it grows with the chick, the __________________________ is pressed against the egg shell where it
can easily absorb _________________ passing through the pores of the egg shell in exchange for
____________________________. The allantois also stores __________________, absorbs albumen
used as food by the embryo and absorbs ____________________ from the shell for bone construction.
 For the first ______________________ the chick can absorb a sufficient amount of calcium from the
yolk but as the formation of bones begins to accelerate the chick must take calcium from the egg shell.
28. There are two distinct extraembryonic blood systems:
 Blood vessels in the ___________________ called allantoic vessels which bring oxygen to the embryo
and take carbon dioxide away.
 The other blood system made of ______________________________ brings nutrients from the yolk to
the embryo.
i. During the first _________________ of its life, the chick relies on the vitelline vessels to also
absorb oxygen but by the 4th day the chick needs more oxygen than can be supplied by only the
vitelline system and begins to rely on the __________________ which will soon take over
___________________.
29. Bird Heart: ___________-Chambered Heart


i. Right Ventricle pumps blood to the lungs.
ii. Left Ventricle pumps blood to the rest of the body.
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1.
 Higher _______________________ rate for flight.
 Average body temp is ________________ degrees.
i. Newly hatched chick is about ___________________degrees.
 Pulse Rate:
i. Rest:
ii. Active:
30. How the chick hatches: Using its __________________ (a tiny sharp horn on the top of its beak) the chick pecks
at the shell ____________________ of times.
 Finally it ____________ through the shell and begins to breathe air directly from the outside.
 After it has made a hole in the shell, the chick stops piping for a few ________________ and rests while
its lungs are getting used to the outside atmosphere.
31. There is a high level of ____________________ in the egg compared with the outside environment.
 This actually causes the neck muscles of the chick to jerk and allow him to peck through the eggshell.
32. After resting the chick continues to pip by beginning to turn slowly inside he egg.
 As it turns, usually ___________________________, the egg tooth continues to chip away.
 In about __________________, the chick has made about _____________________ of a turn inside the
egg.
33. As the chick moves around the shell it begins ________________ on the egg cap.
 Squirming and struggling the chick pushes the cap for about __________________. Finally it breaks free
from the shell, still wet and panting.
 When the chick is completely out of the shell it lies still.
 It is extremely tired. After a rest it begins to ______________ to its feet and gain
________________________.
 Within a few days the egg tooth will ____________________.
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34. Bones and the skeleton: Bones are made of minerals, mostly ______________________ and phosphate. There
are 3 types of bone cells: _________________________, ________________________, and
_________________________________.
 ___________________________ are responsible for making the structure and then laying in the
minerals.
 ___________________________ are responsible for feeding the bone and osteoclasts help shape the
bones as they grow.
 New bone is first created randomly and then reshaped in concentric layers like the rings of a tree. Bone
can be either ________________________ or __________________________.
 _________________________ on the outside provides strength, support and protection.
 _________________________ on the inside allow the bone to be lightweight and provide a space in
which bone marrow can grow.
 ___________________________ makes blood cells.
35. What is cartilage?
 __________________________ is a strong but flexible material like hard rubber. In the embryo, most of
the skeleton is first made of cartilage. As the embryo grows, the _______________________ is replaced
by bone.
i. This is called ______________________.
36. How are bones different in birds?
 Bird bones contain ______________________ and are said to be pneumatized. When a bird takes off for
flight the exaggerated movement of the wings creates an air current which fills the air sacs within the
bones and makes the bird light enough to fly. The bones do no become _________________________
until after the bird ________________.
37. Respiratory System: The ______________are not used for respiration until just before the chick hatches. In the
meantime we have seen that a chick uses the allantois to breathe.
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 The amount of oxygen supplied through the egg shell is enough until the chick starts the exhausting
process of hatching.
 During incubation, the ___________________ which evaporates from the egg is replaced by
________________ which is stored in the air cell.
 By the time the chick begins to hatch, the air cell has grown to fill about _______________ of the egg.
 The chick’s first hatching movements are to _________________ the shell membranes covering the air
cell and take its first breaths with its _________________.
 The oxygen stored in the air cell is _______________________ to allow the chick to break through the
eggshell.
38. How birds breathe: The bird’s lungs are ___________________________ in proportion to its body size
compared to humans; They are only half the size.
 A birds lungs are not ____________________, they do not change size when the bird breathes.
 Specialized elastic structures called ____________________ are connected to the lungs and draw air
through the lungs.
 As air passes through the lungs, ______________________ in the air is exchanged for carbon dioxide in
the blood.
 Birds have two sets of air sacs: _______________________, and ______________________.
i. The ________________________________ include the abdominal and the caudal thoracic air
sacs.
ii. The _________________________________ include the cervical, clavicular and the cranial
thoracic air sacs.
 As we know air sacs even extend into the ___________________. Air sacs inflate or deflate whent eh
size of the bird’s chest changes.
i. The bird controls this by moving its _____________________. The largest of the air sacs, the
abdominal air sac surrounds the _______________________________ and is largely responsible
for breathing while the bird is at rest.
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 As a bird becomes more active, it needs more ___________________________. Increased movement
forces its chest to expand and compress more which in turn inflates and deflates more of its air sacs.
i. This forces more air through the lungs and makes the bird ________________________. When
a bird flies all its air sacs are filled including those in tis bones and makes it light enough to
_________________.
 A bird can also use its air sacs to _________________ by forcing air through its vocal organs like a
bagpipe.
i. Some birds can sing while they fly because they are able to sing when they breathe in as well as
breathe out.
 Constant _____________________ supplies birds with more oxygen than humans. This is necessary to
maintain their high ________________________________ and for flying.
 The lungs of the chick begin to form early to be ready when it __________________________. Air sacs
continue to _____________________ long after the chick is hatched.
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