An organism is a cell that has inherited its DNA from its parents. For example, an egg is a cell; however, it is not an organism. A sperm is a cell; however, it is not an organism. Nevertheless, a zygote is an organism (i.e., an offspring) because it has inherited its DNA from its parents. In his landmark book entitled The Origin of Species (1859), Charles Darwin stated, “Owing to this struggle for life, any variation, however slight and from whatever cause proceeding, if it be in any degree profitable to an individual of any species [i.e., an organism], in its infinitely complex relations to other organic beings [i.e., organisms] and to external nature, will tend to the preservation of that individual, and will generally be inherited by its offspring [i.e., an organism]. Indeed, Darwin stated, “The male and female sexual elements seem to be affected before that union takes place which is to form a new being.”
By the way, a quartz crystal has no DNA.