Do non-bootable data drives have boot sectors?

Possibly a stupid question here, but I’m wanting to confirm a small detail about hard drive workings that up until now I’ve just assumed.

I understand that the 440-byte bootloader won’t be present on a non-bootable data drive (i.e. a drive that doesn’t have an operating system installed to it) but how about the boot sector that usually contains the bootloader in addition to the MBR/GPT partition table itself?

Do drives that are being used purely as data drives require boot sectors, and could running the CMD fixmbr command theoretically fix a data drive’s damaged boot sector?