Ans. The hypothesis for the beginning of life on earth is of 4 stages. The first stage was formed with precursors of life, like amino acids and nucleotides. The second stage of the hypothesis explains the synthesis of complex molecules such as nucleic acids and proteins. The third stage of the hypothesis explains the cell structure formation, which is enclosed by membranous structures. And the fourth stage of the hypothesis explains the cell characteristics, this membranous structure emerged as more chemically selective and developed unique properties.