According to Betty Crocker, you can substitute (in most cases) 2 egg yolks for 1 egg. I use an egg substitute such as Egg Beaters insteat. If you are allergic to eggs, I wouldn't use them because they are made with 99% egg whites. The other 1% isn't mentioned. Good question for Wikianswers.
fish (tuna)
You could use egg replacer. We use it all the time for my brother who is allergice to eggs. It is great to have around so you can replace eggs when you need to.
yes
The milled flaxseed package says you can replace 1 large egg with 1 TBSP of milled flaxseed and 3 TBSP water.
Often refered to as the "nest egg" these artificial eggs are used to replace eggs in the nest of a broody hen. They can also be used to show new pullets where the laying nest is. Some farms use rock or golf balls as nest eggs.
Three quarter cup apple sauce is used to stand in for 3 eggs
Eggs Benedict traditionally uses poached eggs. Eggs Florentine may use poached or shirred eggs.
Remove the eggs. You can replace them with eggs you know are from another bird who was active with a rooster. Your broody hen won't care.
Flax seeds are not an essential ingredient for making a cake and can therefor be omitted. The most commonly used binding agent is eggs. A cake absolutely needs something as a binder. If you don't want to use eggs, you can replace them by gluten or starch.
Mayonnaise is not a direct substitution for eggs in a cake. You need to calculate the amount of oil as well, and also balance the acidity of the mayonnaise with baking soda.
use fertilized eggs
You need to use eggs when you do any type of bread. You can make bread without eggs. :)
Plants use seeds and do not have "eggs".