How to merge hard drives without using Disk Utility?

Hi,

Disk Utility has no visible 'Partition' tab when I click on a hard drive, so I am wondering if there is a way to merge my hard drives without using it?

A possible reason for the Partition tab not being visible is that my MacBook was set up by adminstrators at my school, and perhaps they have locked the hard drive so I cannot merge them.
Is there any way to get around that?

Thanks!