A 'giant mouse' in the laboratory can be produced by gene:

Options

A. mutation
B. synthesis
C. duplication
D. manipulation

Answer

To answer the question about how a 'giant mouse' can be produced in the laboratory through genetic engineering, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Genetic Engineering**:
- Genetic engineering involves altering the genetic material of an organism to achieve desired traits. In this case, we are looking to produce a giant mouse.

2. **Identifying the Options**:
- The question provides several options regarding the genetic procedure that can lead to the production of a giant mouse. These options include gene mutation, gene synthesis, gene duplication, and DNA manipulation.

3. **Evaluating Each Option**:
- **Option A: Gene Mutation**:
- Gene mutation refers to permanent changes in the DNA sequence of a gene. While it can lead to various traits, it is not specifically used to create a giant mouse. Thus, this option is incorrect.

- **Option B: Gene Synthesis**:
- Gene synthesis involves creating artificial genes in the lab. While this is a useful technique, it does not directly lead to the production of a giant mouse. Therefore, this option is also incorrect.

- **Option C: Gene Duplication**:
- Gene duplication is the process of creating copies of existing genes. Although it can contribute to genetic diversity, it does not specifically result in the production of a giant mouse. Hence, this option is incorrect as well.

- **Option D: DNA Manipulation**:
- DNA manipulation involves directly altering the genes of an organism. This technique allows for the insertion of specific genes, such as those responsible for growth hormones, into the fertilized eggs of mice. This can lead to the desired phenotype of a giant mouse due to the overproduction of growth hormones.

4. **Conclusion**:
- After evaluating all options, the correct answer is **DNA manipulation**, as it is the method used to insert growth hormone genes into the embryos of mice, resulting in the production of a giant mouse.

### Final Answer:
A 'giant mouse' in the laboratory can be produced by **DNA manipulation**.