Criminal justice

Please answer the following 2 Questions. 1.During the course of a trial a defendant has a constitutional right to participate in picking his jury. As part of this constitutional right, a defendant is allowed two kinds of challenges he can use when selecting a jury. What are the two challenges? How do these challenges differ? Which challenges are bad for the defendant and why?   2. Sam, a man accused of rape, was tried and convicted by a jury made up of all women. What was the the standard of proof required preponderance of the evidence or beyond a reasonable doubt? Was his constitutional right to trial by jury of his peers violated? Justify your answer.