While performing an experiment on the enzyme amylase, macy uses three different
ph solutions: ph 3.0, ph 4.0, and ph 6.7. she finds that all the starch is broken down fastest at ph 6.7.

how would you justify these findings?

Which statements explains what the fossil records indicates? check all that apply. a) earth is 4.5 billion years old b) many organisms have become extinct c) mammals have always existed on earth d) mass extinctions have occurred several times on earth e) the amount of water on earth has decreased over time?