About root zones

[00Lxns]

Hi!

I'm using Bind to provide some friendly names for my local services, 
such as: svn.localhost, php.localhost (for php prjects), java.localhost 
(for JavaEE) and so on. I have no trouble to set up this behave. But 
also I wants to study how DNS and Bind works, cause I'm studding 
computer science. And I have a problem.

My Bind server is chrooted, and there is no any special options set 
(such as: -c). Bind configuration should be read form /etc/bind/ (as its 
chrooted, for me: /var/bind9/chroot/etc/bind) and this is set.

options {...} are most default...

  If I add 'recursion no;' statement to options, Bind behave as 
Authority-only server. So it no answer for queries like: dig @127.0.0.1 
+norecurse ns. Its understandable for me. dig @127.0.0.1 ns is rq so it 
will be refused also.

If I change 'recursion no;' to 'recursion yes;' dig @127.0.0.1 
+norecurse ns will be refused, but dig @127.0.0.1 return answer 
(recursive query).

Its all ok, but... From where Bind gets informations about root zone?

If I comment line 'include "/etc/bind/named.conf.default-zones"' should 
not be any informations for about root zones, and my local zones too.
/etc/init.d/bind9 restart
rndc flush
(no cahce?)
But Bind further ehav root zones informations. I suspect that it is 
automatically downloaded. I look in tcpdump but I did not discovered any 
transfer.
ifdown wlan0 -> from now there is only loopback interface, again bind9 
restart, rndc flush.
Bind still knows root zones... My question is why? Is there something 
that I don't understand, or something I don't know?

Bind 9.7.3
Linux lex-sclavia 3.0.0-1-686-pae
Debian wheezy (testing)


Thank you for reply.
Luke.