Replication and transcription are similar processes in mechanistic terms because both:

Options

A. Use RNA primers for intiation
B. Use deoxyribonucleotides as precursors
C. Are semiconserved events
D. Invovle phosphodiester bond formation with elongation occuring in the 5'-3' direction.

Answer

### Step-by-Step Solution:

1. **Understanding Replication and Transcription**:
- Replication is the process by which DNA makes a copy of itself, resulting in two identical DNA molecules.
- Transcription is the process where a segment of DNA is used to synthesize messenger RNA (mRNA), which will later be translated into proteins.

2. **Role of RNA Primers**:
- In DNA replication, RNA primers are essential for initiating the synthesis of the new DNA strand. They provide a starting point for DNA polymerase to begin adding nucleotides.
- In transcription, RNA polymerase does not require a primer; it can initiate RNA synthesis at specific promoter regions on the DNA.

3. **Nucleotide Precursors**:
- During DNA replication, deoxyribonucleotides (dNTPs) are used as the building blocks to synthesize the new DNA strand.
- In transcription, ribonucleotides (NTPs) are used to synthesize RNA, which include ATP, CTP, UTP, and GTP.

4. **Semi-Conservative Nature**:
- DNA replication is semi-conservative, meaning each new DNA molecule consists of one old (parental) strand and one new strand.
- Transcription does not involve the semi-conservative mechanism; it simply synthesizes RNA from a single DNA template strand.

5. **Phosphodiester Bond Formation**:
- Both processes involve the formation of phosphodiester bonds. In DNA replication, these bonds link deoxyribonucleotides together to form the DNA backbone.
- In transcription, phosphodiester bonds link ribonucleotides together to form the RNA strand.

6. **Direction of Elongation**:
- Both replication and transcription occur in the 5' to 3' direction. This means that nucleotides are added to the growing strand at the 3' end.

### Conclusion:
Replication and transcription are similar in that both involve the formation of phosphodiester bonds and occur in the 5' to 3' direction, but they differ in the type of nucleotides used and the requirement for RNA primers.