During polymerisation of deoxyribonucleosides triphosphates in bacteria which of the following enzyme is mainly required?

Options

A. DNA dependent RNA polymerase
B. DNA dependent DNA polymerase
C. RNA dependent DNA polymerase
D. DNA gyrase

Answer

To answer the question regarding which enzyme is mainly required during the polymerization of deoxyribonucleoside triphosphates in bacteria, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Process of DNA Polymerization**:
- DNA polymerization is the process of synthesizing a new DNA strand by adding deoxyribonucleotides to a growing chain. This process occurs during DNA replication.

2. **Identify the Role of Enzymes**:
- Different enzymes play specific roles in DNA replication. The key enzyme responsible for the polymerization of deoxyribonucleotides is crucial to this process.

3. **Recognize the Template Requirement**:
- DNA replication requires a template strand. The new DNA strand is synthesized complementary to the template DNA strand.

4. **Determine the Correct Enzyme**:
- The enzyme primarily responsible for the polymerization of deoxyribonucleoside triphosphates in bacteria is **DNA-dependent DNA polymerase**. This enzyme synthesizes new DNA strands by adding nucleotides complementary to the template strand.

5. **Eliminate Incorrect Options**:
- **DNA-dependent RNA polymerase**: This enzyme is involved in transcription, not DNA replication.
- **DNA gyrase**: This enzyme helps relieve supercoiling during DNA replication but does not directly polymerize nucleotides.
- Other options can also be evaluated in a similar manner to confirm that they do not fit the requirement for polymerization.

6. **Conclude with the Correct Answer**:
- The correct answer is **DNA-dependent DNA polymerase**, as it is the enzyme that catalyzes the addition of deoxyribonucleotides to form a new DNA strand during replication in bacteria.

### Final Answer:
The enzyme mainly required during the polymerization of deoxyribonucleoside triphosphates in bacteria is **DNA-dependent DNA polymerase**.