You've made the hypothesis that the steeper the slope, the faster a ball will be rolling when it reaches the bottom.
what should be your independent variable in an experiment testing this hypothesis?
a. how heavy the ball is
b. how steep the slope is
c. how high the ball starts on the slope
d. how fast the ball is rolling at the bottom

Animal bodies (and even plant bodies for that matter) are complex enough that life couldn't exist without enzymes. enzymes are usually large, complex biological catalysts that are expensive to make. enzymes speed up the rate of chemical reactions without being used up during the reaction (they can be reused many times). they are highly specific in the reactions they regulate. knowing what enzymes are and how they function, why does this explain why complex life forms could not exist if there were no enzymes.

If the nucleus of a cell was removed the cell wouldn’t be able to make proteins because

There are fewer than 100 naturally occurring elements in the universe, but there are millions of different unified substances. explain how this can be true.