SANTA CLARA -- With the expected change to a second-year quarterback, 49ers running back Frank Gore can be counted upon to accept more responsibility in the team's offense.That does not mean Gore will carry the ball any more than he did in the first 10 games of the season. After all, Gore ranks eighth in the NFL with 831 yards and five touchdowns on 157 attempts for a 5.3-yard average.Instead, Gore would take on more of a leadership role before the snap.In the first quarter of the 49ers' win Monday night over the Chicago Bears, Gore was seen motioning to kill a play just prior to Colin Kaepernick motioning the same thing.The 49ers changed the play at the line of scrimmage, and Kaepernick hit Randy Moss on a 12-yard pass.Often, the 49ers' quarterback is given two plays in the huddle. Then, he must decide which play to use, based on a pre-snap read of the defense. If the quarterback decides to keep the first play, he yells, "Let it roll! Let it roll!" If the second play is the proper choice, his command is "Kill! Kill! Kill!""I was just going over the film with coach Tom (Rathman), and he makes sure you know everything," Gore said. "He makes us learn everything about the defense, so I just know when the quarterback will make a change and what-not."If he (Kaepernick) doesn't say it, I will, yeah."Alex Smith has been cleared to resume practice this week after experiencing concussion symptoms over the weekend. He took part in limited practice Wednesday. On Thursday, he was again wearing a black jersey, signifying that he is off-limits for contact.The 49ers are scheduled to practice 1 hour, 40 minutes on Thanksgiving Day, concluding at 1 p.m.