I often take some test questions directly from practice exams to encourage students to use these resources. Instructors may also have access to downloadable test banks. I recommend that students visit the text websites and use chapter links as starting points for research projects. Especially useful are links that illustrate how biology concepts relate to everyday life. There are many websites that can be incorporated into an online class.
Tutorials are especially useful to give students practice with complex concepts.
For example, genetics problems can be difficult to explain to online students. I assigned specific Mendelian genetics problems from The Biology Project to online students. Another good starting place to search for science tutorials is Online Tutorials and References . It is not difficult to find helpful science websites. I used a search engine and found several sites in about an hour.