[A]: Recombinant DNA contains DNA from two or more sources.
[R]: Plasmids are small extra rings of DNA in bacteria that carry genes not present in the bacterial chromosome

Options

A. If both A and R are true and R is the correct explanation of A
B. If both A and R are true but R is not the correct explanation of A
C. If A is true and R is false
D. If both A and R are false

Answer

To solve the question, we need to analyze both the assertion and the reason provided:

**Assertion (A):** Recombinant DNA contains DNA from two or more sources.
**Reason (R):** Plasmids are small extra rings of DNA in bacteria that carry genes not present in the bacterial chromosome.

### Step-by-Step Solution:

1. **Understanding the Assertion:**
- Recombinant DNA is defined as DNA that has been artificially made by combining DNA from two or more different sources. This is a fundamental concept in genetic engineering and biotechnology.

2. **Understanding the Reason:**
- Plasmids are indeed small, circular DNA molecules found in bacteria. They are separate from the chromosomal DNA and can carry genes that are not found in the bacterial chromosome. This characteristic allows plasmids to be used as vectors for cloning DNA.

3. **Analyzing the Relationship:**
- The assertion states that recombinant DNA contains DNA from multiple sources, which is true. The reason explains that plasmids can carry additional genes and can be used to create recombinant DNA. This means that the reason supports the assertion because plasmids are often used to introduce foreign DNA into a host organism, thus creating recombinant DNA.

4. **Conclusion:**
- Since both the assertion and the reason are true, and the reason provides a correct explanation for the assertion, we conclude that the correct answer is:
- **Option 1:** Both assertion and reason are true, and reason is the correct explanation of assertion.