Question

Dr. Michelle Wang at Cornell University studies DNA replication and protein synthesis. Her group researches how a protein called helicase unzips the DNA strand.
After DNA is unzipped, what is the next step in DNA replication?
A. Messenger RNA forms along the exposed DNA bases.
B. A chromosome with two identical strands of DNA is formed.
C. Nitrogen bases pair up with the DNA strands.
D. Ribosomes attach to DNA and move along the strand.

Answer 1

Answer:

C. Nitrogen bases pair up with the DNA strands.

Explanation:

The correct option would be that nitrogen bases pair up with DNA strands.

DNA replication is a process during which a DNA molecule makes a copy of itself. It represents one of the major processes of gene expression.

DNA replication happens in several steps and it involves several important enzymes: The steps can be summarized in chronological order as follows:

• The double helix structure of the DNA is first unwound using a helicase enzyme.
• A short RNA sequence known as primer binds to each DNA strand. Binding is done at a single site on the leading strand while it is done at multiple sites on the lagging strand.
• An enzyme known as DNA polymerase then elongates the primers by adding nucleotide bases to grow new strands.
• Once elongation is complete, the primer disengage and the RNA nucleotide bases are replaced DNA equivalence, the okazaki fragments of the lagging strands is joined by a ligase, the nely synthesized strands are proofread and each strand winds up to their respective parent strand.

Hence, the correct option would be that nitrogen bases pair up with the DNA strand.

Correct option: C.