chicken embryo development

A. INTRODUCTION
1. Background
The nature of the organism is to have the ability to form a new individual or form a new generation to defend the preservation of species. This capability is called as the ability to reproduce. The process of reproduction as we know it is not an instant process, but involves a series of continuous processes, such as gametogenesis, fertilization, embryo development until a new individual is born.
One characteristic of living beings is the ability of these creatures to reproduce or proliferate. Reproduction aims to maintain the kind of extinction, in which new individuals are produced can be similar or different from the parents. Known three-way living things reproduce the spawn, breed, breed and lay eggs.
The pattern of embryonic development in chickens (aves) basically the same as frogs (amphibians), namely through several stages of division. Cleavage at the cleavage meroblastik aves, namely division which only takes place in chip institutions only. From the results it obtained blastoderm division. The next stage is blastulasi, stage of gastrulation, and organogenesis neuralisasi stage.
Based on the above explanation, we need to hold an experience that could support our understanding on matters relating to the development of the embryo. One way is to conduct lab work, ie activities where we can observe directly all the processes discussed above. In this lab we will examine the development of chicken embryos the incubation period 24, 48, and 72 hours.
Thus, we not only know the process of chicken embryonic development through theory alone, but also through practical activities. From the results of lab work, then we can compare the theory obtained from the lecture bench with those observed directly.
2. Purpose
The purpose of this practicum are:
1. Studying the formation of organs in various stages of the chick embryo age.
2. Studying the embryonic layer that will form the organ.
B. PREVIEW OF LITERATURE
Chickens have feathers that provide insulating (warm coverings) for the body, thus making it smaller, but provides the ability to maintain temperature and has a hollow bones and a single gonad (in females), an enlarged and active only dive breeding season (Kimball, 2006).
Knowledge of the fertile and whether egg is needed, especially at the hatchery. In addition knowledge to physical selection of egg, egg fertile also need to know. Physical selection can be done including cleaning egg from its parent dirt, cracks or absence of eggs and egg shape size (normal or not). But apart from that is not less important knowledge about the fertile / infertile eggs viewed from inside the egg (Anonymous, 2008)
Cleavage dikoskoidal meroblastik can be found in chickens. Cleavage took place on blastodisk contained in the polar anima eggs. While the yolk is also split. Cleavage takes place within the reproductive tract (Adnan, 2008).
Like a baby in his mother's belly, chick embryo in the egg also experienced significant growth from day to day. Embryo in the egg as the beginning of the life of a chicken turned out to have the uniqueness of growth in it. Knowledge about the development of the embryo in the egg in the hatchery, but please note does not hurt if we had participated know the development of embryos from day to day (Anonymous, 2008).
Regional heads have folding of the embryo called the fold of the head and split between the intra-and extra embryos. During embryonic development, Albumen will lose fluid so that it becomes thick and the volume is reduced. Towards the end of the incubation period, residual yolk and the yolk sac enter into the abdominal cavity and then close the abdominal wall. Residual yolk is used by baby chicks as food supplies during the early period of his life outside the egg (Yatim, 1990)
Division which lasted chiped acquired institution as much as 3-4 blastoderm cell layer. The second cleavage is perpendicular first division, and the region contribute to four blastomeres are also not completely separate. The third division, two divisions of simultaneous parallel with mining division produced 8 blastomeres. The fourth division is a division of the circle and cut out all fields previous division. The fifth cleavage is radial cleavage, cutting the field of the fourth division and produce blastomeres edge-blastomeres that do not separate completely incorrect (Adnan, 2008).
According to (Adnan, 2005), There are four kinds of extra-embryonic membranes are present in higher vertebrates, namely:
1. Yolk sac is very closely spanknopleura membrane functions in nutrition, especially in the reptilian embryo and yolk in birds because having that very much.
2. Amniotic sac . It is a thin membrane derived from somatoplura form a sac that surrounds the embryo and contain the fluid, the presence of this membrane in birds and mammals, reptilian cause of this animal group called the amniotic.
3. Allantois sac . It is a bag that berb entuk from the ventral colon evaginasi back in the early stages of development the main function or as a place of shelter and the development or storage of urine and as a gas exchange organ between the embryo with its outer environment.

C. OBSERVATION METHOD
1. Tools and Materials
a. Tools
1) Petri dish
2) Tweezers
3) Incubator
4) Scissor
5) Filter paper
6) Microscope
b. Material
1) Egg which is incubated for 24, 48, and 72 hours.
2) NaCl physiologies
2. Work Procedure
a. Incubated the egg for about 24, 48, and 72 hours in incubator with 37o-38o C temperature.
b. Broke the incubated egg and pour to the petri dish which is contain NaCl physiologies.
c. Site the filter paper and make the hole in the center which is fit with the embryo.
d. Cut the yolk, moved the filter paper so the embryo went with the paper.
e. Dipped the embryo to NaCl physiologies, and moved to microscope.

D. RESULT AND DISCUSSION
1. Observation result

2. Discussion
a. Observation I
Eggs were observed on the first observation of eggs that had been incubated for 24 hours, which has shown the existence of an embryo that is still colored nodes. At this time the chicken embryo has undergone cleavage blastula and gastrula stage in which the visible presence pellusida area that is visible above the nodes subgerminal cavity. And opaka area, an area that was dark, located on the edge blastodisk. This area consists dariarea opaka vaskulosa, opaka vitelin, blood islands in the area opaka vaskulosa. And opaka area, an area that was dark, located on the edge blastodisk. This area consists dariarea opaka vaskulosa, opaka vitelin, blood islands in the area opaka vaskulosa. After 24 hours of incubation, there were spots of blood on eggs and embryos are still difficult to be observed with light microscope, so that the development of an embryo at stage 24-hour incubation could not be observed. Around the embryo there are areas that the yellow color quite different from the color of egg yolk or yolk surrounding the embryo, making the embryo as if inside a circle which is located in the egg yolks (the yolk). This area is called the extra embryos that consist of the area and the area opaka pellusida. Khalaza not clearly visible.
b. Observation II
Eggs on the observation that both eggs have been incubated for 48 hours. It appears the first line in the center of blastoderm. Among extraembrionic annexis vitelin visible membrane which has the main role in embryo nutrition. At this time the embryo looks covered by 3 layers ie ectoderm body organs will be tellensefalon, diensefalon, rombensefalon, mensefalon, miensefalon, and vasikula optics. Venous sinus formed mesoderm, visceral cleft atrium, ventricle, limit the amnion, and tail bud, and visceral endoderm seen a gap, intestine front, two will be the respiratory tract.
c. Observation III
The third observation of eggs in an egg that has been incubated for 72 hours, which has seen a Rhombencephalon located next to the dorsal and telensephalon approached the development of the heart. Head more towards the posterior folds. In the caudal region formed primordial feet, mesoderm will experience growth that will develop into primordial wings. Consists of the brain tube lateral ventricle, three in the diensephalon, cerebral aquad on mensephalon, and ventricular four on rhombensephalon and canal on the spinal cord. Stimulate the formation of optic cup and lens lens cornea stimulates the formation. Ototis and ductus endolimfatikus will become the inner ear. There are front intestine, colon and bowel middle rear.

E. CLOSING
1. Conclusion
Based on the observations, can be summed up as follows:
a. In the 24-hour incubation period of chicken embryos has experienced seemingly division of the embryo is actually clear.
b. During the 48 hour incubation, the embryo is experiencing the formation of the heart, optic vesicle to the formation of the eye.
c. During the 72-hour incubation, the chick embryo has undergone blood vessel formation, would eye the ear and tail.
d. embryonic layer that forms the layers ectoderm, endoderm, and endoderm which then form the various organs through the cleavage blastula, gastrulation and organogenesis
2. Suggestion
a. For apprentice, be a good practice and listen to the instruction of assistant.
b. For assistant, we hope for the next practicum, not just one assistant that manage this practicum.

BIBLIOGRAPHY
Adnan.2005. Perkembangan Hewan. Makassar : Jurusan Biologi FMIPA UNM.
Adnan.2008. Perkembangan Hewan. Makassar : Jurusan Biologi FMIPA UNM
Anonim. 2008. Perkembangan Embrio Ayam. http://one.indodeskri.Com/judul-
skripsi-tugas-makalah/biologi-umum/pengamatan-tahapan perkembangan-embrio-ayam. Accessed at January 15th 2011

Kimball, 2006. Biologi Jilid III edisi kelima. Jakarta: Erlangga

Yatim. 1990. Reproduksi dan Embriologi. Bandung: Tarsito.