Question

Why is DNA replication considered a semiconservative process?

A. New DNA molecules are built on the template DNA as Okazaki fragments, which are then cut away from the template strand.

B. Each resulting DNA molecule contains one strand from the original molecule and one newly built strand.

C. All new DNA molecules are built on the same template strand, allowing the template to be used again.

D. The sequence of each new DNA strand is different from the sequence of the template strand, maintaining the uniqueness of each.

Answer 1

Step-by-step explanation:

The correct answer is B. DNA replication is considered a semiconservative process because each resulting DNA molecule contains one strand from the original molecule and one newly built strand. This was first demonstrated by the Meselson-Stahl experiment in 1958, where they labeled the DNA of E. coli with a heavy isotope of nitrogen and then switched to a lighter isotope of nitrogen. They found that after one round of replication, the resulting DNA molecules contained one heavy and one light strand, indicating that DNA replication is semiconservative.