TV HIGHLIGHTS

Young Sheldon, 8 PM on Ch. 7 and Ch. 12: This prequel to “The Big Bang Theory” closes its fourth season with a finale called “The Wild and Woolly World of Nonlinear Dynamics,” in which young Missy’s (Raegan Revord) first heartbreak sparks a series of events affecting brother Sheldon (Iain Armitage) and the entire Cooper household. Fans can rest easy on one point, though: There’s no real-world heartache for this show’s cast and creative team, since CBS recently renewed “Young Sheldon” for three more seasons.

Growing Up Hip Hop, 9 PM on WE: The original edition of this popular reality show franchise, which follows the offspring of such hip hop legends as Rev Run and Treach, returns for its sixth season, adding some new faces to its cast, including Grammywinning producer Stevie J, daughter Savannah, son Stevie Jr., music industry veteran Luther “Uncle Luke” Campbell and his daughter Cree. Among the returning characters, Rev Run’s daughter, Angela Simmons, is into a heavy new romance with a professional boxer, while a pair of dueling weddings inadvertently uncover a shocking family secret.

Rebel, 10:01 PM on Ch. 22 and Ch. 9: After Helen (guest star Mary Mcdonnell) is denied critical surgery, Rebel (Katey Sagal) goes to the mat to save her life, and continues to push Cruz (Andy Garcia) to recall the heart valve for closer study in the new episode “Heart Burned.” Elsewhere, Cassidy and Lana (Lex Scott Davis, Tamala Reneé Jones) try to help Luke (Sam Palladio) when his personal life threatens both his career and personal reputation. Mo Mcrae, Adam Arkin, Abigail Spencer, Dan Bucatinsky and Sharon Lawrence guest star.