Revelations - S5-E22
Heimdall: As a race, the Asgard reproduce exclusively through a process of enhanced cellular mitosis.
Samantha Carter: Are you serious? You have no other means of propagation?
Heimdall: No.
Jack O'Neill: Carter?
Carter: They're clones, sir. All of them.
O'Neill: Ah. Well, that answers a few questions.
Heimdall: In fact, for nearly a thousand years we have been physically incapable of achieving cell division through meiosis.
O'Neill: [Confused, looks at Carter] Hmm?
Carter: [Whispering] Sexual reproduction, sir.
O'Neill: Ah. [To Heimdall] A thousand years?
Heimdall: It is usually not something we discuss with other races.
O'Neill: This I understand.
Chosen answer: Report 30185 is a joke report referring to the time when SG-1 go back in time to 1969 in the episode '1969'. The joke is that Colonel O'Neil knocked up a hippie and made sure Mitchel was taken care of throughout his life, like how he got into the 302 program while his buddy, a better pilot, did not.