Bring Up or Water Down

In my Pre AP Biology courses, I have a dilemma.  Do I teach the curriculum on a college prep basis, or do I make sure that all of my students are doing well?  I have several students that are not doing well right now.  I look at their grade and it is apparent that they are not doing homework or taking any extra time for Pre AP Biology.  For a lot of my students, this is the first year that they have had homework.  One of our feeder schools does not allow homework.  This is making my job increasingly tough.  I do not give much homework, only about one night per week, but expect them to read the material outside of class.  Too many of my students feel as though they can get the material just by showing up to my class.  They are not wanting to do anything outside of my class.  I do have several A's because it is class that students can be successful.  So my dilemma is, do I quit giving outside work so that the everyone will be successful, or do I keep going at a college prep level and leave the others behind?  In the famous words of Monday Night Football...You make the call!!!