1. 4-H Embryology
Penn State
4-H
Responsibility!

2. 4-H Pledge I pledge my Head to clearer thinking
my Heart to greater loyalty
my Hands to larger service
and my Health to better living
for my club, my community
my country and my world.
Page 19

3. What is Embryology?
Embryo + ology

4. Embryology = the study of the beginning of life of any living thing
What is Embryology?
Embryology = the study of the beginning of life of any living thing

5. Let’s talk about chickens…

6. Rooster = Male
Hen = Female

7. Pages 5-6
Key words:
Ovary
Oviduct
Pigment
How long does it take for a hen to make and egg?

8. That’s the hen, what about the rooster?
The hen produces this egg independently.
This egg has hen cells only.
This egg will not develop an embryo.
This is the type of egg you buy at the grocery store.
This egg is INFERTILE. H
When hens and roosters are together they mate
and the hen produces this egg.
This egg has hen and rooster cells.
This egg will develop an embryo.
This is the type of egg in the incubator.
This egg is FERTILE. H R
The hen and rooster mate. Parent cells unite inside the hen. The fertile egg is formed.

9. Shell
Outer Shell Membrane
Page 4
Inner Shell
Membrane
Air Cell
Albumen
Chalazae
Yolk
Germinal Spot
Small, white
Blastodisc
-Infertile
4 x larger, tan, circle
Blastoderm - Fertile

10. Incubation
Natural Incubation: the hen sits on the eggs until they hatch.
Artificial Incubation: use an incubator and copy the hen’s actions
until the eggs hatch.
4 Components of Incubation:
Temperature
Humidity
Exercise
Clean, fresh air
Page 3

11. Candling

12. Page7

13. 4
The embryo looks like a spider.
Label:
Air Cell
Embryo
Blood Vessels
Yolk
Albumen
Shell

14. The embryo looks like a spider. Label: Air Cell Embryo Blood Vessels 4
The embryo looks like a spider.
Label:
Air Cell
Embryo
Blood Vessels
Yolk
Albumen
Shell
Shell
Air Cell
Yolk
Homework:
Page 3 - reading
Page 4 - bottom
Page 5 – top
Page 13- Scientific drawing
Embryo
Albumen
Blood Vessels
Page 13