What begins to happen on one of the unzipped strands?

What begins to happen on one of the unzipped strands?

• A. Complementary bases are attaching to the unzipped strand
• B. RNA polymerase binds to start transcription
• C. Histones wrap around DNA
• D. Nucleotides detach and degrade

Answer: (A)

When DNA unwinds, each exposed strand serves as a template for building a new complementary strand. Incoming nucleotides with bases that pair to the exposed bases attach themselves (A pairs with T, G pairs with C) and are linked by DNA polymerase to form a new strand. This is why complementary bases attaching to the unzipped strand is the right description here. The other processes—RNA polymerase initiating transcription, histones wrapping DNA, or nucleotides detaching and degrading—aren’t the immediate events taking place on the unzipped DNA during replication.

When DNA unwinds, each exposed strand serves as a template for building a new complementary strand. Incoming nucleotides with bases that pair to the exposed bases attach themselves (A pairs with T, G pairs with C) and are linked by DNA polymerase to form a new strand. This is why complementary bases attaching to the unzipped strand is the right description here. The other processes—RNA polymerase initiating transcription, histones wrapping DNA, or nucleotides detaching and degrading—aren’t the immediate events taking place on the unzipped DNA during replication.