Here's why:

* Conjugation is a form of horizontal gene transfer where genetic material (usually in the form of plasmids) is directly transferred from one bacterium to another through a pilus (a bridge-like structure).

* Eukaryotes do not typically use conjugation as a means of transferring genetic information. They have more complex mechanisms for reproduction and genetic exchange, such as meiosis and sexual reproduction.

However, it's important to note:

* Some eukaryotes can engage in a process called "conjugation" in a different context. This involves the fusion of two cells (like in certain algae or protozoa) for the purpose of exchanging genetic material. This is not the same as bacterial conjugation and is more akin to sexual reproduction.

So, while both bacteria and some eukaryotes may have a process called "conjugation", it is fundamentally different in its mechanism and purpose.