It is appropriate that artificial insemination is a key plot point in “The Back-Up Plan” (2010). The entire film smacks of artificiality. Don’t get me wrong. Jennifer Lopez has many moments of adorability and watching her be cute for 108 minutes wouldn’t be the worst way to fill a Sunday afternoon. But this rom-com is just so TV movie-of-the-week. The romantic interest is a TV guy (Alex O’Loughlin) and most of the cast are TV people (Tom Bosley, Noureen DeWulf, Linda Lavin, Melissa McCarthy). The producer? You guessed it: CBS Films. It’s not a film, it’s a cross-platform marketing tool.