Cellular processes are carried out by many different types of molecules, mostly proteins. the function of each protein molecule depends on its shape which, in turn, is determined by the protein's specific sequence of what?

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?