Sonic Hedgehog.

Chapters 1 and 2 were pretty easy to read but chapter 3 was a little different.
It got into a more wordier and required more concentration. I sometimes had
to reread a few lines to make sure I was understanding what I was reading.
The text it getting more challenging but isn't that why we are taking
an AP biology class. I found it very interesting to read about the sonic hedgehog
gene that is in almost any animal. It was also intriguing to read about the different
experiments geneticists performed in order to discover what they needed to
about this ZPA and how it plays a role in developing limbs anywhere from shoulder to
fingers and legs. Basic genetics is pretty simple to understand but trying
to find "your inner fish" and how it all changed over millions of years
is veeeerryyy complicated. But overall the book is intriguing no matter
how complicated it is getting. (: