Read the following four statements (A-D)
A. The first transgenic buffalo, Roise produced milk which was human alpha-lactalbumin enriched
B. Restriction enzymes are used in isolation of DNA from other macromolecules
C. Downstream processing is one of the step of rDNA technology
D. Disarmed pathogen vectors are also used in transfer of rDNA into the host
which of the two statements have mistakes ?
(a) B and C
(b) C and D
(c) A and C
(d) A and B

Options

A. B and C
B. C and D
C. A and C
D. A and B

Answer

To solve the question, we need to analyze each of the four statements (A-D) and identify which two contain mistakes.

### Step-by-step Solution:

1. **Analyze Statement A**:
- Statement A claims that "The first transgenic buffalo, Rosie, produced milk which was human alpha-lactalbumin enriched."
- **Mistake**: This statement is incorrect because Rosie was the first transgenic cow, not a buffalo. Therefore, this statement contains a mistake.

2. **Analyze Statement B**:
- Statement B states that "Restriction enzymes are used in isolation of DNA from other macromolecules."
- **Mistake**: This statement is misleading. Restriction enzymes are primarily used to cut DNA at specific sequences, which allows for the isolation of specific DNA fragments rather than isolating DNA from other macromolecules. Thus, this statement also contains a mistake.

3. **Analyze Statement C**:
- Statement C mentions "Downstream processing is one of the steps of rDNA technology."
- **Correct**: This statement is true. Downstream processing involves the extraction and purification of the desired product after the recombinant DNA has been produced.

4. **Analyze Statement D**:
- Statement D states "Disarmed pathogen vectors are also used in transfer of rDNA into the host."
- **Correct**: This statement is also true. Disarmed vectors, such as modified Agrobacterium, are indeed used to transfer recombinant DNA into host organisms.

### Conclusion:
- The two statements that contain mistakes are **A and B**.
- Therefore, the correct answer is **(d) A and B**.