Features Of Embryonic Development
During this essay, the features of embryonic development are analysed and comparisons between the developments of different species will be explored. Developmental biology is the study of the activity which leads to the growth and maturation of organisms.
The Red Jungle Fowl (Gallus gallus) is thought to be the ancestral to the modern domestic chicken. (Fumihito et al., 1994).  Chickens have had a long association with man, according to D. Burt 2007, domestication took place 8,000yrs ago in Thailand.  The chicken (Gallus gallus domesticus) is used as a model organism, it has many features which qualify it for this role. Fertilized chicken eggs (therefore embryos) usually take exactly 21 days to fully develop and hatch, this makes them easy to work with and incubate. By cutting into the egg directly, observing can also be done with ease. 
To understand how chickens develop, two dissections can be carried out, task 1: a dissection of an embryo which has been incubated for 11/2 day and task 2: a dissection of an embryo which has been incubated for 4 days. The procedures for these tasks can be found in the appendices. Drawings of observations can also be found in figure 5.
Adult features present? …show more content…
Eighteen somites (pairs), somites are divisions of an animal’s body containing the same internal structures. They are made up of paraxial mesoderm, paraxial mesoderm is the area of the mesoderm in the neurulating embryo which is produced with the neural tube. Somites later subdivide into sclerotomes, myotomes and dermatomes.  In figure 2 the otic vesicles can be seen, one is visible, the other is denoted only by a slight protuberance. The neural tube can also be seen, this has developed from the neural plate and will go on to form the full central nervous