Statement I: pBR322 is a natural plasmid.

Statement II: Agrobacterium tumefaciens is a natural genetic engineer.

Only statement II is correct.

 The correct answer is Option (2) -Only statement II is correct.

Statement I: pBR322 is not a natural plasmid. It is, in fact, an artificial plasmid that was constructed in the lab for use in genetic engineering experiments. It contains genes for antibiotic resistance (e.g., ampicillin and tetracycline resistance) and a variety of restriction sites, making it a widely used cloning vector.

Statement II: Agrobacterium tumefaciens is often referred to as a "natural genetic engineer" because it has the ability to transfer a part of its DNA (the T-DNA) into the genome of plants, causing the formation of tumors (crown gall disease). This natural process has been exploited in biotechnology to introduce desired genes into plants, making A. tumefaciens an important tool in plant genetic engineering. The tumor inducing (Ti) plasmid of Agrobacterium tumifaciens has now been modified into a cloning vector which is no more pathogenic to the plants but is still able to use the mechanisms to deliver genes of our interest into a variety of plants.