What could be the possible harm of using antibiotic resistant gene as a selectable marker in plasmid, used for gene transfer in production of GM food?
(A) GM food contains the enzyme produced by the antibiotic resistance gene that was used during gene tranfer in genetic engineering. This could cause allergies since it is a foreign protein.
(B) The bacteria present in the alimentary canal of the humans could take up the antibiotic resistance gene present in GM food.
(C) The bacteria in the human alimentary canal would then become resistant to the concerned antibiotic.
(D) The transgene may be transferred through pollen to their wild relatives and make weeds more persistant and damaging.

Options

A. A only
B. Both B and C
C. A,B and C
D. A,B,C and D

Answer

To analyze the possible harm of using an antibiotic-resistant gene as a selectable marker in plasmids for gene transfer in the production of genetically modified (GM) food, we can evaluate each of the given statements step by step.

### Step-by-Step Solution:

1. **Understanding the Use of Antibiotic Resistance Genes**:
- Antibiotic resistance genes are often used as selectable markers in genetic engineering to identify successfully modified organisms. However, their use raises concerns about potential risks.

2. **Evaluating Statement A**:
- **Statement**: "GM food contains the enzyme produced by the antibiotic resistance gene that was used during gene transfer in genetic engineering. This could cause allergies since it is a foreign protein."
- **Analysis**: This statement is true. The protein produced from the antibiotic resistance gene can be recognized as foreign by the human immune system, potentially leading to allergic reactions.

3. **Evaluating Statement B**:
- **Statement**: "The bacteria present in the alimentary canal of humans could take up the antibiotic resistance gene present in GM food."
- **Analysis**: This statement is also true. Horizontal gene transfer can occur, allowing gut bacteria to acquire the antibiotic resistance gene from GM food.

4. **Evaluating Statement C**:
- **Statement**: "The bacteria in the human alimentary canal would then become resistant to the concerned antibiotic."
- **Analysis**: This statement is true as well. If gut bacteria take up the antibiotic resistance gene, they can become resistant to the antibiotic, making it ineffective in treating infections.

5. **Evaluating Statement D**:
- **Statement**: "The transgene may be transferred through pollen to their wild relatives and make weeds more persistent and damaging."
- **Analysis**: This statement is misleading. While gene transfer can occur between crop plants via pollen, the claim that it would directly make weeds more persistent is not accurate. Pollen transfer typically occurs between similar species, not from crops to unrelated wild relatives.

6. **Conclusion**:
- The correct statements regarding the potential harm of using antibiotic-resistant genes as selectable markers are A, B, and C. Statement D is incorrect.

### Final Answer:
The possible harms of using antibiotic-resistant genes as selectable markers in GM food production include:
- (A) Allergic reactions due to foreign proteins.
- (B) Uptake of antibiotic resistance genes by gut bacteria.
- (C) Development of antibiotic-resistant bacteria in the human gut.