After the completion of replication, each DNA molecule will have one parental strand and one newly synthesized strand. This scheme is known as:

Semi-conservative DNA replication

The correct answer is Option (1) → Semi-conservative DNA replication  

While proposing the double helical structure for DNA, Watson and Crick had immediately proposed a scheme for replication of DNA. To quote their original statement that is as follows: ‘‘It has not escaped our notice that the specific pairing we have postulated immediately suggests a possible copying mechanism for the genetic material’’ (Watson and Crick, 1953). The scheme suggested that the two strands would separate and act as a template for the synthesis of new complementary strands. After the completion of replication, each DNA molecule would have one parental and one newly synthesised strand. This scheme was termed as semiconservative DNA replication.