Real Science 4 Kids Level 1 Biology from Gravitas Publications: Students are introduced to definitions, classifications, morphology and experiments involving organisms. This is the teacher's manual for Level 1 Biology for grades 4-6. Real Science 4 Kids published by Dr. Rebecca Keller, deserves this honorable mention. I’ve heard so many great things about these books, but I haven’t used them myself, so I can’t speak first hand about them. However, I have a friend who was a chemist at a pharmaceutical company BC&H (before children and homeschooling), and she loves these. She’s even planning to use them to teach a chemistry co-op next year. Check our website for my review once I’ve tried them. Retails for $26.95