BEHIND-THE-SCENES WITH DESTINY'S CHILD, ON "20/20," FRIDAY NOVEMBER 19 ON ABC

Elizabeth Vargas Reports on a Female Identical Twin Who Transformed Herself into a Transgender Male

John Stossel Reports on College Cheating

Whether you call them "Independent Women" or "Survivors" or hit-makers, Grammy-winning R&B trio Destiny's Child has reunited after a three-year break to launch solo careers. The three singers - Beyonce, Michelle Williams and Kelly Rowland - invited "20/20" behind-the-scenes for a rare glimpse of their world as they prepared for their new tour, and also spoke candidly to ABC News Correspondent Deborah Roberts about stunning the critics who doubted they would ever share the stage again. The report airs on "20/20" FRIDAY, NOVEMBER 19 (10:00-11:00 p.m., ET) on the ABC Television Network.

And: Elizabeth Vargas introduces viewers to identical twins who could not be more different. Thirty-five years ago, near Anchorage, Alaska, Juanita and Liana Barbachano were born identical female twins, and now they are brother and sister. Juanita, who transformed herself into a transgender male named Juan, says he knew "that I was really a boy" since the age of three. "We've always had a brother-sister relationship, although we were two females," says Liana, who is married and has eight children. So how could identical twin girls, conceived from the same fertilized cell, sharing the same DNA, turn out to be so different? Vargas reports on the compelling and often painful journey of Juanita to Juan, and how it raises profound questions about what determines human identity: nature or nurture?

Plus: John Stossel reports on cheating in college and how it has become big business for some.

"20/20" is anchored by Elizabeth Vargas and John Stossel. David Sloan is the executive producer.