Why are hens' eggs very satisfactory for the study of embryology?
363791
Fertilized eggs can be easily maintained in humidified incubators and during early stages of development the embryo floats on to of the egg yolk that it is using for nutrition. As the embryo grows it sinks into, or below the, yolk. The regular appearance of somites allowed early experimenters to acurately stage the embryo. The embryo was accessible and easy to manipulate (limb grafts/removal etc) that were informative about developmental processes. Chicken cells and tissues (neural ganglia/fragments) are also easy to grow in tissue culture. The discovery that quail cells have a different nuclear appearance meant that transplanted cells (chick/quail chimeras) could be tracked during development.
1020710
The types of eggs based on yolk characteristics are described as:\nIsolecithal: sparse evenly distributed yolk, eg., sea urchin, mouse\nMesolecthal: moderate amount of yolk, often unevenly distributed, eg., frog\nTelolecithal: dense yolk concentrated at one end, eg., bird, reptile\nCentrolecithal: yolk concentrated at the middle of the egg, eg. fly
147711
Eggs aren't bad, but like all the things in live to much is never good. But the egg itself is a very good thing voor the body: Eggs contain about 6 grams of high quality protein, so high that it is used as the standard by which other foods are measured. Eggs are also a rich source of vitamins, including A, E and K and a range of B vitamins such as B12 (energy), riboflavin and folic acid. Eggs also contain all eight essential amino acids needed for optimal muscle recovery and building valuable minerals like calcium, zinc and iron.\nwant to know more about the egg click on the link and they will tell you more.
366427
The egg came first, because before there were any chickens at all, there was the species that mutated/evolved into the chicken (some sort of dinosaur, no doubt). That species was invariably an egg laying creature, and therefore, there were eggs long before there were chickens.
680269
You mean chicken eggs that we eat? It's not necessary. Generally the eggs we eat aren't fertilized.
833119
The white of an egg is a very simple protein. Globulin.. the yolk of an egg contains sufficient lecithin to combat any microscopic globule to be found in that yolk,, (cholesterol). Any one familiar with  lecithin is aware of its ability to combat cholesterol. In fact the origin of the word comes from the Greek, meaning yolk of an egg. Most, 2/3 of people eating eggs will find their cholesterol reduce rather than elevate.. the other 1/3 will have no change. This has personally been observed, when a patient was advised to eat eggs when there had been no change in the many months of prescribed meds for the condition. He was normal at his next 3 month test.
159512
The chicken because God created all of the animals first.  The egg came shortly after. :D
516957
The hen of course. Each species was sent in pair and then they multiplied. Imagine a mammal, it does not lay eggs, so it must have come as in its animal form first.
571426
An egg produced by "natural means" or by "artificial insemination" are exactly the same.  The only difference would come by what the hen was eating during the developement of the egg.  If she is commercially used to lay eggs, then she is fed a chicken scratch and corn diet.  If she is free range then she eats whatever she finds on the ground (worms, bugs, seeds).  In which case the free range hen would have a more flavorful egg regardless of how the egg was started.
451579
Between Religion and Science, i believe that the CHICKEN came first. In relation to Religion, God created all the animals, including the chicken, for a specific purpose. Reproducing another kind of them, which in chickens, they lay eggs. In Science, we all knew in the theory of evolution, that all living things came from single celled animals, but evolved to multiple-celled animals eventually. But, it doesnt mean that being a single celled animal makes you an EGG because its already an animal, only one celled. So the answer is probably the CHICKEN.
548166
well\nit's the same as follows:\ndid egg come first or a hen?\ni wish u find your answer.
1140353
scrambled eggs prove the existence of God...and that He does have a sense of humour.\n\nlight fluffyness that is delicious in the morning...and it came from a chicken's behind.\n\nta-da.
33079
Your question is similar to "does a woman need a man around to ovulate?" Hens lay eggs regularly. The rooster's function is to fertilize the eggs. So roosters are rarely around in commercial egg farms, because fertilized eggs are generally not desired.
870009
A hen can only lay an egg if it has been fertilised. Unfertilised eggs (ova) remain within the egg. Only if the ova are fertilised do they progress further, to enclose the zygote/embryo within a calcified shell (egg) which is then laid.\nTherefore its is impossible for a laid egg to be haploid (n) because such an egg just wouldnt be laid.
325368
Probably our ancestors saw animals eating other eggs and followed suit.  Once we had established that eggs were tasty, and we had domesticated chickens, we just kept eating eggs.
212862
Raw whole eggs are a phenomenally inexpensive and incredible source of high-quality nutrients that many of us are deficient in, especially high-quality protein and fat.\n\nYou can read more about the myths of eating raw eggs at the link below....
193309
the egg, because before hens existed there were proto-hens that laid eggs as well. One day one of those proto-hens evolved and the first hen was born.