1. Conservative hypothesis: In the conservative process, DNA sequences are separated into two. Each sutra acts as a mold and creates new sutras. Then the old sutras are placed together and the new sutras are placed together. As a result, two strands of DNA are formed. That is, two strands of one DNA are old and two strands of other DNA are new.
2. Dispersive hypothesis: In the dispersive process, DNA strands are broken into two. Then different amounts of old and new fragments combine to form two DNA molecules. This process is not acceptable.
3. Semiconservative hypothesis: The process in which two new DNAs are formed from one maternal DNA and each of the two new DNAs has a maternal source and a new source is called a semiconservative process. In 1957, scientist Stent first used the term semiconservative. In 1958 Mathew Meselson & Franklin Stahl proved the semiconservative hypothesis in E. coli bacteria. In 1960, Herbert Taylor demonstrated semiconservative replication by experimenting with bean plant root cells. In 1960, scientist Sueka demonstrated semiconservative processes in human HeLa cells. In 1961, scientist Symon demonstrated the semiconservative process in the algae Chlamydomonas.