Can a defendant waive their constitutional rights by pleading guilty?

Thus, " [j]ust as a defendant may affirmatively waive constitutional rights to a jury trial, to confront and cross-examine witnesses, to the privilege against self-incrimination, and to counsel as a consequence of a negotiated plea agreement, so also may a defendant waive the right to appeal as part of the agreement. [Citation.] As the Court of Appeal noted in People v. Vargas (1993) 13 Cal.App.4th 1653, 1659, 17 Cal.Rptr.2d 445... If a defendant may waive important constitutional rights by pleading guilty, it follows a fortiori that a defendant may expressly waive his statutory right to appeal as part of a plea agreement .... " ( People v. Aparicio (1999) 74 Cal.App.4th 286, 289, 87 Cal.Rptr.2d 750, citing People v. Panizzon (1996) 13 Cal.4th 68, 80, 51 Cal.Rptr.2d 851, 913 P.2d 1061 ( Panizzon ).)