The number of phosphodiester and hydrogen bonds formed during perparation of rDNA using EcoRl respectively are .

Options

A. 2&6
B. 2& 16
C. 4 & 16
D. 4 & 8

Answer

To determine the number of phosphodiester and hydrogen bonds formed during the preparation of recombinant DNA (rDNA) using EcoRI, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Process**:
- EcoRI is a restriction enzyme that cuts DNA at specific sequences. When preparing rDNA, DNA from two different organisms is combined. The EcoRI enzyme creates sticky ends on the DNA fragments.

2. **Identify the DNA Fragments**:
- Assume we have two DNA fragments: one from the first organism and one from the second organism. The EcoRI cuts the first organism's DNA, creating a specific sequence where the new DNA can be inserted.

3. **Counting Phosphodiester Bonds**:
- Phosphodiester bonds are formed between the sugar and phosphate groups of adjacent nucleotides in a DNA strand.
- In the example, we can visualize the DNA strands after EcoRI has cut them and where the new DNA is inserted.
- For the given DNA sequence, we can count the phosphodiester bonds:
- If we have 4 nucleotides in the new DNA sequence, there will be 4 phosphodiester bonds formed between them.

4. **Counting Hydrogen Bonds**:
- Hydrogen bonds form between complementary bases of the DNA strands.
- In DNA, adenine (A) pairs with thymine (T) through 2 hydrogen bonds, and guanine (G) pairs with cytosine (C) through 3 hydrogen bonds.
- If we have a sequence that pairs with the new DNA, we can count the hydrogen bonds:
- For example, if the new sequence has A-T and G-C pairs, we can count the total hydrogen bonds formed.

5. **Final Count**:
- After counting, we find:
- **Phosphodiester Bonds**: 4
- **Hydrogen Bonds**: 16

6. **Conclusion**:
- Therefore, the number of phosphodiester bonds formed is 4, and the number of hydrogen bonds formed is 16.

### Final Answer:
- Number of Phosphodiester Bonds: 4
- Number of Hydrogen Bonds: 16