The Lizard-Spock Expansion - S2-E8
Continuity mistake: When Sheldon goes to speak to Leonard, he is sitting on the couch. Camera cuts to Raj for one second, then to Penny and you can see Sheldon has crossed the apartment and is now in the hall. There is not enough time to move that far in that time. (00:09:05)
The Lizard-Spock Expansion - S2-E8
Continuity mistake: When Leonard is talking to Penny in the laundry room; as he walks forward to ask her about whether him dating Stephanie is wrong, the box of washing powder on the machine behind him alternately has its lid closed or open. (00:14:00)
The Lizard-Spock Expansion - S2-E8
Continuity mistake: At the very beginning, Leonard's Diet Coke keeps changing position without anyone touching it.
The White Asparagus Triangulation - S2-E9
Continuity mistake: When Sheldon is in Penny's apartment trying to get her to tell him why her relationship with Leonard failed, the yellow tee-shirt on the red pillow next to him keeps changing position.
The White Asparagus Triangulation - S2-E9
Continuity mistake: When Sheldon, Raj and Howard are talking in the cafeteria, Sheldon's drink keeps moving position.
The White Asparagus Triangulation - S2-E9
Continuity mistake: When Leonard is helping Sheldon open the jar, the red napkin which he left on the couch where he was sitting changes position or vanishes in every shot.
The White Asparagus Triangulation - S2-E9
Continuity mistake: When Sheldon is questioning Raj and Howard in the cafeteria, the bottle of water is on Raj's tray faces the camera with the barcoded side. But in one closeup it rotates to show the logo-branded side.
The White Asparagus Triangulation - S2-E9
Continuity mistake: When climbing the stairs at the start, Penny and Sheldon turn the corner and carry on the conversation. Camera cuts and now they turn the corner again and continue their conversation without breaking it.
The Vartabedian Conundrum - S2-E10
Continuity mistake: When Leonard and Penny are talking in the dryer room, the size of the towel Penny is folding keeps changing. (00:15:00)
The Vartabedian Conundrum - S2-E10
Continuity mistake: When Stefanie and Leonard are talking in bed towards the end, Stefanie's arm moves from on her head to on her pillow instantly. (00:16:30)
The Vartabedian Conundrum - S2-E10
Continuity mistake: When Sheldon is talking via the laptop, the amount of letters in the words he says is different to the amount of keys hit.
The Vartabedian Conundrum - S2-E10
Continuity mistake: When Sheldon is told that he can't talk, he goes from sitting to standing instantly.
The Vartabedian Conundrum - S2-E10
Continuity mistake: When Stephanie asks Leonard why he hasn't told her about Penny, he spills some of the pancake mixture out of the bowl he is stirring. In some shots the spilled mixture vanishes and the appears again.
The Vartabedian Conundrum - S2-E10
Continuity mistake: When Leonard, Raj and Howard are talking about Leonard's new trousers, the items on the tray behind Howard keep changing.
The Bath Item Gift Hypothesis - S2-E11
Continuity mistake: When Penny takes a drink from the egg-nog carton before kissing Leonard on the cheek, between shots the logo-branded label changes which direction it faces in her hand. (00:16:45)
The Bath Item Gift Hypothesis - S2-E11
Continuity mistake: When Leonard gives Penny her christmas gift, as she unwraps it she tears the paper off so that most of the box is exposed. In the next shot much more of the wrapping is back intact and differently positioned. (00:19:40)
The Bath Item Gift Hypothesis - S2-E11
Continuity mistake: When Sheldon emerges with all of the bath item gift baskets for Penny, he drops them on the floor and chair. Between shots one of the baskets on the chair changes from being an upright green-ribboned basket, to a toppled-over white-ribboned basket. (00:19:50)
The Bath Item Gift Hypothesis - S2-E11
Continuity mistake: Near the start, when the camera is on Raj, David Underhill is seen in the top left-hand corner of the screen shaking someone's hand, already in the cafeteria. Then, when the camera is on Wolowitz, David is just walking into the door of the cafeteria. David sits down to the right of the man sitting at the table, then shortly afterwards David is now sitting where the other guy was, originally.
The Killer Robot Instability - S2-E12
Continuity mistake: When Penny and Howard are arguing near the start, Penny has her arms crossed in one shot and down by her side in the next. (00:04:50)
The Financial Permeability - S2-E14
Continuity mistake: When the guys are using the whiteboard to figure out their cinema plans, Sheldon draws two black X's on the board with a marker. In the following shots the appearance of the X's changes. (00:00:30)
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.