Which statement about $\mathrm{RNA}$ is correct?

During the formation of nucleic acid polymers, what molecule is removed?

What is the primary structural difference between $\mathrm{RNA}$ and $\mathrm{DNA}$?

Which of the following is not a component of $DNA$?

What enzyme allows a retrovirus to synthesize $D_{N}A$ from an $R_{N}A$ template?

How is $\mathrm{RNA}$ different from $\mathrm{DNA}$ in terms of structure and function?

Which is a major difference between messenger RNA ($m\mathrm{RNA}$) molecules and transfer RNA ($t\mathrm{RNA}$) molecules?

Which $\mathrm{DNA}$ fragments move farther in the gel during electrophoresis?

Which enzyme is responsible for synthesizing new $DNA$ strands during the $PCR$ process?