What chemical reaction takes place between an egg shell and vinegar ?

The reaction of the eggshell in vinegar is an acid-base reaction. When you submerge an egg in vinegar, the shell dissolves, leaving the inner semi-permeable membrane intact. Vinegar (acid) breaks apart the solid calcium carbonate crystals (base) in the eggshell into their calcium and carbonate parts.

Explanation:

desert perennials often survive by remaining dormant during dry periods of the year, then springing to life when water becomes available. most annual desert plants germinate only after heavy seasonal rain, then complete their reproductive cycle very quickly.