Is it possible to create drop-down list with bold values? Can you make certain values not selectable?

So I'm making a form and looking to use drop down list boxes to limit options. I'm looking to have bold headings within the list that aren't select-able. An example is below. Are either of these options possible?

Fruit

  Apples

  Bananas

Vegetables

  Carrots

  Green Peppers

Meats

  Beef

  Chicken

Thanks

Josh