CK 12 offers a wide variety of textbooks and resources for free. You can even create your own textbook by adding chapters from their library. I created a textbook during the Covid-19 pandemic because students were learning from home. They did not have their textbooks (which were outdated anyway.)
This free version aligned to their current curriculum, which used Miller and Levine’s Dragonfly Book. Students complete reading guides for each chapter. Many of the guides are formatted to be completed on Chromebooks.
The list below contains reading guides for each of the chapters. The guides also contain direct links to the chapters for students to access. I do not have answer keys for these guides, but most are simple enough. The goal is for students to just read the text, so the questions are not difficult.
CK 12 Reading Guides
You can also access the Google folder or download each individually. If you want to edit the documents, please copy them to your own drive. Files listed are “view only.”
I also have similar reading guides for OpenStax Biology, which is more advanced. I use this text in my AP Biology (Dual credit) class.