Here's why:

* Oak trees are a diverse genus (Quercus) with many species. Each species has its own unique chromosome number.

* Diploid refers to the number of chromosomes present in a normal body cell (somatic cell).

To find the specific diploid number for a particular oak species, you would need to research that species. For example, you might find information like:

* Quercus robur (English Oak): Diploid number = 24

* Quercus rubra (Red Oak): Diploid number = 24

* Quercus alba (White Oak): Diploid number = 24

Keep in mind that even within a species, there can be occasional variations in chromosome number due to mutations.