You're very close! Your description of the nucleus is accurate, but there are a few minor things to adjust:

* "pl nuclei" should be "plural nuclei".

* "from Latin or nuculeus meaning kernel" is a bit redundant. "Nucleus" is the Latin word for "kernel."

* "It contains most of genetic material?" should be "It contains most of the cell's genetic material."

Here's the corrected version:

In cell biology, the nucleus (plural: nuclei) from Latin "nucleus" meaning "kernel" is a membrane-enclosed organelle found in eukaryotic cells. It contains most of the cell's genetic material.

Let me know if you have any other questions about cell biology!