Season 3, Episode 10 - The Gorilla Experiment
Aired December 7, 2009
When Penny wants to learn more about Leonard's work, she turns to Sheldon for lessons. Sheldon views the opportunity to teach Penny rudimentary physics as an experiment, but his teaching style quickly brings Penny to tears. Meanwhile, Howard gets jealous after his girlfriend Bernadette also takes an interest in Leonard's research.
Season 7, Episode 23 - The Gorilla Dissolution
Aired May 8, 2014
A bad day on the set of her movie causes Penny to reconsider the decisions she's made in her career - and her romantic life. Meanwhile, Howard and Bernadette struggle to take care of an injured Mrs. Wolowitz, while Raj gets relationship advice from Sheldon.