I took micro and A&P1 together. My advisor had actually suggested to do it that way. It was not easy whatsoever but it can be done! My nursing friends all did it the same way and not one of us failed either class. There would be days where both classes would have a test so I would have to study a certain amount for micro and spend the rest of my time on A&P, considering that was the class I was most worried about at the time. So just prioritizing will help you a lot. It will not be easy I can promise you that but as long as you go in knowing that you are going to have to put in some hard work you will do just fine.