Turn play -call down or fold?

[Percy101]

Both of these hands occured against relative newcomers to the table, so my query concerns whether it would be standard to call down or fold against a turn raise from an unknown in such situations.
For the pocket 9s hand I would also be interested to hear how much of a difference it would make to your decision if the overcard were a K,Q or J rather than an Ace.
For the A7s hand I was wondering whether you would be more or less likely to call down/fold if the board were less co-ordinated.
Comments on all streets would also be welcome. Thanks.

Party Poker 1/2 Hold'em (9 handed) converter

Preflop: Hero is BB with 9[img]/images/graemlins/diamond.gif[/img], 9[img]/images/graemlins/heart.gif[/img].
<font color="#666666">4 folds</font>, MP3 calls, <font color="#666666">2 folds</font>, <font color="#CC3333">Hero raises</font>, MP3 calls.

Flop: (4.50 SB) 4[img]/images/graemlins/club.gif[/img], 5[img]/images/graemlins/heart.gif[/img], 7[img]/images/graemlins/diamond.gif[/img] <font color="#0000FF">(3 players)</font>
<font color="#CC3333">Hero bets</font>, MP3 calls.

Turn: (3.25 BB) A[img]/images/graemlins/diamond.gif[/img] <font color="#0000FF">(3 players)</font>
<font color="#CC3333">Hero bets</font>, <font color="#CC3333">MP3 raises</font>, Hero?


Party Poker 1/2 Hold'em (9 handed) converter

Preflop: Hero is BB with A[img]/images/graemlins/heart.gif[/img], 7[img]/images/graemlins/heart.gif[/img].
<font color="#666666">1 fold</font>, UTG+1 calls, MP1 calls, <font color="#666666">4 folds</font>, SB completes, Hero checks.

Flop: (4 SB) A[img]/images/graemlins/diamond.gif[/img], 4[img]/images/graemlins/diamond.gif[/img], Q[img]/images/graemlins/heart.gif[/img] <font color="#0000FF">(4 players)</font>
SB checks, <font color="#CC3333">Hero bets</font>, UTG+1 calls, <font color="#CC3333">MP1 raises</font>, SB folds, <font color="#CC3333">Hero 3-bets</font>, UTG+1 folds, MP1 calls.

Turn: (5.50 BB) J[img]/images/graemlins/club.gif[/img] <font color="#0000FF">(2 players)</font>
<font color="#CC3333">Hero bets</font>, <font color="#CC3333">MP1 raises</font>, Hero?