Consider the following statements regarding the DNA-mediated gene transfer and choose the correct answer:<br>1. DNA fragments carrying the gene to be transferred are mixed with a carrier DNA<br>2. They are then precipitated out with a calcium phosphate buffer<br>3. The precipitate is used to transform target cells<br>4. The Ca-precipitated DNA enters the cell by exocytosis

Correct Answer: Only 1, 2 and 3 are true