The type of sexual exchange that occurs among bacteria where DNA is carried into a bacterial cell by a bacteriophage is called transduction.

Here's how it works:

1. Bacteriophage infection: A bacteriophage (a virus that infects bacteria) infects a bacterial cell.

2. DNA packaging: During the phage's replication cycle, some bacterial DNA may be mistakenly packaged into phage particles.

3. Transfer: When these phage particles infect a new bacterial cell, they inject the packaged bacterial DNA along with their own genetic material.

4. Recombination: The transferred bacterial DNA can then recombine with the recipient cell's genome, introducing new genetic information.

There are two main types of transduction:

* Generalized transduction: Any bacterial gene can be transferred.

* Specialized transduction: Only specific genes adjacent to the phage integration site are transferred.

Transduction is a significant mechanism for horizontal gene transfer in bacteria, allowing for the spread of genetic information and potentially contributing to the development of antibiotic resistance.