David,
The activity looks fine. The worksheet takes a while to open, because it was the first time for me to use the Word web thing. What is the advantage of the word web thing over a word doc in the file manager? I think I know but want to hear from you.
Perhaps the teacher notes should say something about not using this activity for assessment as the data collection and processing are given.
This is a great video which would summarise cell structure and DNA replication in an inspiring way for 2nd year Biology students. Although the last 10 minutes argues against evolution.