Jordan and Ronnie, Big Brother 11

CBS has announced (most) of the 13 houseguests who will be competing for the $500,000 grand prize on Big Brother 11 this summer.

Host Julie Chen made the reveal on CBS' Early Show, but only introduced 12 players. The remaining mystery guest — which the blogosphere suggests will be a player from a past season — will be announced July 7, two days before the show's premiere.

Check out photos of the Big Brother 11 houseguests

The cast is relatively young (the oldest contestant is a 41-year-old school teacher/DJ) and features the usual suspects: a buxom blonde, a beefy jock, an edgy type (tattoos!) and a bikini model. But this might also be the season of the nerd. One of the houseguests has a Ph.D. in neuroscience, while another is an obsessive gamer who collects Star Wars memorabilia.

This season, the houseguests will be grouped into cliques — popular, athletes, brainiacs and off-beats — just like in high school. Also, the house has gone green this season, with most of the walls being constructed from reconstituted wood panels. Houseguests will also have to recycle and use an automatic composter.

Get a first look at the redesigned Big Brother house

Big Brother 11
premieres Thursday, July 9 at 8 pm/ET.