How is humor created in Act I scene ii of The Merchant of Venice?

Act I, scene ii of The Merchant of Venice, introduces the audience to Portia. The audience will come to appreciate Portia's keen intellect and dry sense of humor. She is weighed down by the problems which face her and the need to find a husband according to her father's will. Nerissa, Portia's servant, discusses all of Portia's suitors and Portia stereotypes and finds fault with each one of them. Humor is created in Portia's descriptions and her acute sarcasm. By the end of the scene, the irony is not lost on the audience as Portia expresses her interest in Bassanio - who has no money and is intent on hiding his money problems by loaning from Antonio.

In describing her suitors, Portia suggests that the Neapolitan prince "does nothing but talk of his horse" (37) to the point that Portia suggests his mother may have "played false with a smith;" in other words, placing his parenthood in question. This would have amused Shakespearean audiences enormously as they would have imagined the outcome of such an indiscretion. In describing the "County Palatine" who "does nothing but frown," Portia even uses rhyme (palatine / rhyme) to suggest how ridiculous a union with him would be.  

An English audience would have appreciated how Portia discredits each of the European and Scottish suitors, and as the English like to make fun of the shortcomings of others, the members of the audience would have enjoyed her attack on a typical English "baron," especially because they would have come across just such a hapless person themselves. The audience would have also appreciated Portia's daring. A modern audience can appreciate the tongue-in-cheek humor.