The Communication Deterioration - S8-E21
Penny: You are a wise man.
Sheldon: Well, Penny, who's smarter, the wise man or the person who comes to him for advice?
Penny: Oh, I guess you're right. Maybe it is the person who asks.
Sheldon: No. It's the wise man. That's why he's called the wise man. You know how I know that? I'm the wise man.
The Colonization Application - S8-E17
Amy: We could also be the first people to procreate on Mars.
Sheldon: You just can't keep it in your space pants, can you?
The Intimacy Acceleration - S8-E16
Penny: If you were to die this evening with no opportunity to communicate with anyone, what would you most regret not having told someone?
Sheldon: So it would be today? Huh... Well, I suppose there's something satisfying about dying on my birthday.
Penny: Today's your birthday?
Sheldon: Yes.
Penny: Well that's always been a secret. Not even Amy knows.
Sheldon: Well, I don't enjoy presents. And the thought of people jumping out and yelling surprise fills me with more dread than the words "George Lucas Director's Cut."
The Intimacy Acceleration - S8-E16
Sheldon: Just out of curiosity, Penny, if this experiment does make us fall in love, would you drive me to Lake Geneva, Wisconsin, for Gary-Con? It's the only convention celebrating the life and work of Gary Gygax, the co-creator of Dungeons and Dragons.
Penny: You know what, I can honestly say if we fall in love, not only will I drive you there, I will buy you all the dragon T-shirts you want.
Sheldon: Okay, babe, let's do this.
The Intimacy Acceleration - S8-E16
Bernadette: You better find my husband's mother, 'cause one way or another we're walking out of this airport with a dead woman.
The Comic Book Store Regeneration - S8-E15
Raj: Wait, hang on. If you're really Nathan Fillion, what's the line from Firefly about your bonnet?
Customer: I swear by my pretty floral bonnet, I will end you.
Leonard: That's it. That's the line.
Raj: Although, I knew the line, doesn't make me Nathan Fillion.
Customer: Do you want the picture or not?
Raj: I want a picture with Nathan Fillion.
Customer: How about a picture with a guy who looks like Nathan Fillion, but a little more annoyed than Nathan Fillion usually is?
Leonard: What do you think?
Raj: Eh, it's good enough for Facebook.
The Comic Book Store Regeneration - S8-E15
Stuart: I can't believe she's gone. That woman took me in. If it wasn't for her, I would have been homeless.
Amy: One of us would have taken you in.
Stuart: Yeah, I don't recall any offers. But you know what, I'm glad it worked out the way it did, because I got to know this wonderful person.
Suggested correction: Genes can be dormant. Which allows them to skip generations. Therefor Missy's children could actually get the "mutated" gene. This is especially true since Sheldon and Missy are twins. Also, since the episode is about who out of Leonard, Howard or Raj, Sheldon would allow to "mate" with his sister, there is the added "insurance" of getting any smart genes from any of the 3 Lothario's mentioned above.
If you are going to try to argue with a geneticist about genetics, please use the correct terms. Sheldon is not referring to a recessive gene - there is no such thing as a dormant gene - he is speaking of a randomly mutated gene. Those are the words he used. If he had inherited a homozygous recessive karotype - one recessive gene from each of his parents - then somewhere in his family tree there would similarly gifted people, in which case he would use the correct term - a recessive gene. If Missy is a heterozygotic dominant karotype possessing the recessive gene for super-genius and the dominant for ordinary intelligence then mating her with Howard, Raj or Leonard would be a waste of time as their dominant genius gene would prevent the recessive super-genius gene from being expressed in the phenotype of the resulting child. The child would be highly intelligent but not on Sheldon's standards. It doesn't matter if Sheldon does not know any of this as he refers several times to a randomly mutated gene, not a recessive one. Missy does not carry the super-genius gene. The posting is correct.
Sheldon is prone to magical thinking when necessary to preserve his obsessive need to control his environment. He may have simply ignored the flaw in his reasoning, as even the most intelligent humans do when venturing outside their ares of expertise. He may be interested in the science of genetics, but his Ph.D. in physics doesn't qualify him as an expert in that field.