1). As show in the quote, Tybalt's prejudice towards Mercutio, resulted in him fighting and killing Mercutio for no other reason than Mercutio was a Montague. In turn, this event filled Romeo with anger and caused Romeo to take revenge and fight and kill Tybalt. This chain reaction was all caused because of Tybalt's prejudice towards the Montagues. Tybalt was willing to fight and kill any of the Montagues, which then caused Romeo to retaliate and kill Tybalt. As explained, Tybalt's prejudice against the Montagues caused himself to take a drastic measure by writing a note of challenge to Romeo, and also forced Romeo to take an extreme action in spite of vengeance.
A second example of prejudice is Capulet's prejudice in relation to the Montagues which strongly influenced Juliet to act in secrecy. Juliet was forced to take desperate action by first having herself married to Romeo in secrecy. Evidence of this marriage was when Friar Lawrence married them: "For, by your leaves, you shall not stay alone / Till holy church incorporate two in one"" (2.6.). Due to Capulet's prejudice, Juliet was forced to have a wedding in secrecy because her father would never allow her to marry a Montague due to his prejudice against Montagues. Another drastic measure Juliet had to perform because of Capulet's prejudice was to fake her death by drinking vile. Right before she drank the fake death-inducing vile she said: "Romeo, I come! This do I drink to thee"" (4.3.). Once again because of Capulet's prejudice (which firstly forced Juliet to be married in secret), Juliet had to fake her death to avoid marrying Paris the next day, as Capulet had arranged, since she was already married to Romeo. Marriage is a huge commitment, and because of Capulet, Juliet was forced to marry Romeo in secrecy and later consume a fake death-inducing vile to avoid another marriage. These events involving Juliet were definitely drastic measures and were largely influenced by Capulet's prejudice towards Montagues.