How many different kinds of proteins does one cell contain?

Ageologist determines that a sample of a mineral cant be scratched by a steel nail but can be scratched by a masonry drill bit based on this information the sample mineral has to be softer than

Are the earth's ocean floor and continents the same age geologically? why or why not?

Factors that can increase mutation rates a. high temps b. low temps c. food additives d. uv rays