Describe the relationship between piggy and ralph changes during the novel? and what impact does piggy have on ralph at the end?be specific please

You only get one question, so I'll address the first.  The
relationship between these two changes as Lord of the Flies
progresses.  Initially, Ralph is not particularly interested in Piggy in any
way.  In fact, under circumstances in which you'd expect them to work together and
cooperate, Ralph is perfectly willing to walk away from Piggy.  Ralph does his best to
ignore him; once the other boys arrive, he is quick to get a laugh at Piggy's expense by
announcing the name Piggy hates.  Piggy has always needed Ralph; he just has too much
going against him to find friendship among the other boys.  Ralph, on the other hand,
doesn't need Piggy.  As time goes on,  though, Ralph comes to recognize his need for
Piggy's intellect. Together, they unite against the hunters and the slow move into
uncivilized, disorganized, improper behavior.  Piggy forgives Ralph, and Ralph gains a
new appreciation for Piggy.  Towards the end, Piggy is scared, really scared.  He knows
that, if something happens to Ralph, Jack would love nothing more than to get rid of
him.  Their final scene together is poignant, as Piggy blindly clings to Ralph as he
strives to assert himself and the rules of civility upon Jack and his fellow savages. 
To no avail.  Once Piggy is gone, Ralph is in a purely physical battle for his
life.