Three basic steps are required for making GMO are :
I. Identification of DNA with a desirable gene .
II. Introduction of identified DNA into the host .
III. Maintenance of introduced DNA to its progeny .
What is the correct sequence of involvement ?

Options

A. `II rarr I rarr III`
B. `I rarr III rarr II`
C. `II rarr III rarr I`
D. `I rarr II rarr III`

Answer

To solve the question regarding the correct sequence of steps required for making a genetically modified organism (GMO), we can break down the process into three distinct steps as follows:

### Step-by-Step Solution:

1. **Identification of DNA with a Desirable Gene**:
- The first step in creating a GMO is to identify the specific DNA that contains the gene of interest. This gene should have desirable traits that can benefit the organism or enhance its characteristics.

2. **Introduction of Identified DNA into the Host**:
- Once the desirable gene has been identified, the next step is to introduce this DNA into the host organism. This is typically done using various techniques such as transformation, transfection, or gene editing methods.

3. **Maintenance of Introduced DNA to its Progeny**:
- The final step involves ensuring that the introduced DNA is maintained and expressed in the progeny of the host organism. This means that the new genetic material should be stably integrated into the host's genome so that it can be passed on to future generations.

### Correct Sequence:
Based on the steps outlined above, the correct sequence of involvement is:
1. Identification of DNA with a desirable gene (Step I)
2. Introduction of identified DNA into the host (Step II)
3. Maintenance of introduced DNA to its progeny (Step III)

Thus, the correct answer is **Option 4: 1, 2, 3**.