Approvals with empty groups

Hi there, 

A bit more of a general question. If there is an approval required from a group, but the group currently does not have any members, does this approval then go to Manager of the group? If not, who does the approval go to? Also, what effect does this have on the flow if the approval doesn't go anywhere?

I hope the question makes sense; thanks in advance for your help.

Kind regards, 

G