Egg
An egg is a reproductive capsule produced by many animals to reproduce. Fertilized eggs contain embryos which develop into whichever animal laid it. Some animals have eggs which are only visible at a cellular level, like humans for example. Usually the egg contains all the nutrients the developing animal needs, but mammals some develop within their mothers (such as mammals), almost eliminating the need for eggs. Most eggs are considered tasty, such as chicken eggs, but they tend to rot after a short amount of time unless kept cold. However, eggs, almost entirely in their yolks, provide excellent sources of nutrition due to their abundance of vitamins and minerals, particularly several fat-soluble vitamins less prevalent among plant-based foods; vitamin D3, naturally exclusive to animal products, are found in egg yolks.
Unusual characteristics
The liquid in eggs have an unusual characteristic of solidifying when heated. In addition, eggs are a perfect, complete protein.
Fragility of eggs
Due to their thin and brittle shells, eggs are fragile.