Even being a visual learner the trick is to take notes, even if you never look at the notes ever again its good to write them down, you are more likely to remember something you have written down rather than to just look at it. Science is something that could be easy, you just have to take it at your own pace, don't try to learn science by giving it a quick read or glance at it.
Answer:
Red blood cells (RBC)
The gene pool of the population will remain relatively constant.
