Are there 10.4 systems that can upgrade to 10.11

Yes.  The mid-2007 iMac with 10.4.10 and mid-2007 MacBook Pro with 10.4.9 can be upgraded to 10.8, through 10.11.  Older MacBook Pros and iMacs can't upgrade to 10.8 or 10.9.  Although if they have a Core2Duo processor they can upgrade to 10.7.5 with the same process below.  CoreDuo, CoreSolo processors can only upgrade to 10.6.8.   G5 processors, and G4 processors with a minimum of 867 Mhz can only upgrade to 10.5.8 (although note they will lose access to Classic compatibility).

No Mac Mini, Mac Pro*, MacBook (without secondary name), with 10.4 installed, may be upgraded to 10.8 through 10.11.

To determine what system was prebundled with your Mac, see this tip if you lost your discs or bought it used or refurbished without discs:

https://discussions.apple.com/docs/DOC-6413

This user tip explains the process to upgrade:

https://discussions.apple.com/docs/DOC-6271

Note: Additional systems that had 10.5 preinstalled can also upgrade to 10.9 or 10.10, following the steps on the following tip:

Which 10.5 systems can upgrade to 10.11?

* An unsupported method of upgrading older Mac Pros with 10.4.7 or later is on this tip: http://www.jabbawok.net/?p=47