water
oxygen
sodium chloride
Gradually as the result of many intermediate steps is my answer because as life on Earth for example started off with simple atoms making molecules, and as the time went past more complex compounds were be produced. And from there later on unicellular organisms started appearing. Nothing in evolution that I know of happens in a short time, at least from the human perspective.
There are two major types of reproduction in living organisms, these are sexual and asexual reproduction. Asexual reproduction is a type of reproduction in which an offspring is derived from a single parent. The offspring derived from the parent inherit DNA molecule from its parent, thus, the genetic information in both the parent and the offspring are identical. Thus, in asexual reproduction, the parent and the offspring possess identical genetic make up.