Which of the following statements is incorrect?

Options

A. Plasmids have the ability to replicate within the bacterial cells independent of the control of chromosomal DNA
B. Some plasmids have only one or two copies per cell whereas, the others may have 15-100 copies per cell
C. Bacteriophages have the ability to replicate within the bacterial cell independent of the control of chromosomal DNA
D. Transformation is a procedure of separation and isolation of DNA fragments

Answer

To determine which statement is incorrect, we will analyze each of the given statements one by one.

### Step 1: Analyze the first statement
**Statement:** Plasmids have the ability to replicate within bacterial cells independent of the control of chromosomal DNA.

**Analysis:** This statement is correct. Plasmids are extrachromosomal DNA molecules that can replicate independently of the chromosomal DNA within bacterial cells.

**Conclusion:** This statement is correct.

### Step 2: Analyze the second statement
**Statement:** Some plasmids may have only one or two copies per cell whereas the others may have 15 to 100 copies per cell.

**Analysis:** This statement is also correct. The copy number of plasmids can vary significantly, with some plasmids having low copy numbers (1-2) and others having high copy numbers (15-100).

**Conclusion:** This statement is correct.

### Step 3: Analyze the third statement
**Statement:** Bacteriophages have the ability to replicate within the bacterial cell independent of the control of chromosomal DNA.

**Analysis:** This statement is correct. Bacteriophages can indeed replicate within bacterial cells, and they can do so independently of the bacterial chromosomal DNA.

**Conclusion:** This statement is correct.

### Step 4: Analyze the fourth statement
**Statement:** Transformation is a procedure of separation and isolation of DNA fragments.

**Analysis:** This statement is incorrect. Transformation refers to the process by which genetic material (DNA) is taken up by a cell from its surroundings, leading to genetic change. The procedure for separation and isolation of DNA fragments is typically done using techniques like gel electrophoresis.

**Conclusion:** This statement is incorrect.

### Final Conclusion
The incorrect statement among the options provided is:
**Transformation is a procedure of separation and isolation of DNA fragments.**