Question 5

DNA molecule separates into two template strands.

The second step in DNA replication is when the DNA molecule separates into two template strands. This step is crucial as it allows the replication process to proceed by creating individual strands that serve as templates for synthesizing new complementary strands.

A) Complimentary nucleotides are added to each template strand.

This option describes a later step in the DNA replication process, where nucleotides are incorporated into the growing new strands. This occurs after the template strands have been separated, making it not the second step in the sequence.

B) DNA molecule separates into two template strands.

This option is the correct answer as it identifies the step that naturally follows the unwinding of the DNA molecule. The separation of the strands is essential for allowing replication machinery access to the genetic code, making it the second step in the replication process.

C) Two DNA molecules, each with a template strand and a new strand, are formed.

This step occurs at the end of the replication process when two identical DNA molecules have been synthesized. It is not the second step, as it follows both the unwinding and the separation of the original DNA strands.

D) DNA molecule unwinds.

While this step is vital for initiating DNA replication, it occurs first in the sequence. The unwinding of the DNA must happen before the strands can separate, making this option incorrect as the second step.

Conclusion

The correct answer, identifying the separation of the DNA molecule into two template strands as the second step in replication, is critical for the accurate duplication of genetic material. Other options either describe steps that occur earlier or later in the process, highlighting the importance of understanding the correct order of operations in DNA replication.