8.Your choice talk about something you learned or ask a question about something that is confusing you

I learned about genetic traits, and genes. How parents pass down their genes, will affect how kids look like. I also learned how to solve the genetic genes by using punnet squares. And knowing how to separate, and understand which is dominant trait, and which is recessive trait. After knowing this, i learned how to graph them using family tree. If the parents are both recessive, the kids are 25% dominant, 50% Aa and 25% aa recessive. What confuses me is fossils. I'm not sure which is index fossil and not sure if which is artifact.