Does the contents in assets folder contribute to compiled game data when no scenes/prefabs use it?

I just imported standard assets but only need a small piece from it in my scene.

However I am very curios to know if things like standard assets where large parts of the plugin/library are not actually being used, are the scrips and any other data used in the final build?

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continuation:
I also load things using AssetBundles, and they could have scrips/objects that were not included in any scene when the game was built but are dynamically added.

So even if I only use the "fire" elements from StandardAssets in my compiled game, can I still create a scene as an AssetBundle and use the "water" asset?

Thanks!!