Linking master to subsheet and back
 

Is there a way to have data entered into a master sheet and have it replicate to a linked sheet, which is easy to do but what I need is to also have data entered on the subsheet replicate back to the master.
I also want to be able to add new rows to the master and have the added rows replicate on the subsheet. A tall order I know.
Thanks in advance for any help with this.